Spitfire Mk. I versus Me 109 E
A Performance Comparison

This narrative makes no attempt at being a full and detailed history of the Spitfire I or Messerschmitt BF 109E, rather its intent is to examine in detail, with emphasis placed on the use of primary source archival material supported by personal accounts, the performance aspects of these aircraft that most books only briefly – and frequently incorrectly - mention.

The Spitfire first flew in March 1936. Entry into service was with No. 19 Squadron at Duxford in August 1938 while 18 more squadrons were equipped with Spitfires by the start of the Battle of Britain in July 1940. The first BF 109 prototype flew in September 1935, ironically powered by a Rolls-Royce Kestrel engine. The first production model, the BF 109B-1, was delivered in February 1937. The BF 109 E, the varient that saw action during the Battle of Britain, entered into service early in 1939. Given the multiple aircraft combat environment in which they fought, the performance of the Spitfire Mk I and the Messershmitt Bf-109E was sufficiently close that the results of combat would generally fall to initial position, numbers, tactics and pilot experience.


Level Speed

Early production Spitfire Is achieved top level speeds is excess of 360 mph. Trials by the Aeroplane and Armament Experimental Establishment (A.& A.E.E.) at Martlesham Heath and Boscombe Down obtained maximum level speeds of 362 mph for Spitfire I, serial number K.9787, 367 mph for K.9793, and 364 mph for L.1007. 1a 1b 1c   These aircraft, however, do not represent the condition of those that first fought against enemy fighters over Dunkirk in May 1940. A number of improvements were necessary to make the Spitfire ready for war. The addition of a bullet proof windscreen was one of those improvements, however, it cost about 6 mph and resulted in a maximum top level speed ranging from 355 to 360 mph during the Battle of Britain. Another improvement, raising the engine limitations to +12 lb/sq.in. on the Merlin II and III, had little effect on maximum level speed at full throttle height and above, however, this improvement did have a very significant impact on level speeds from sea level up to about 15,000 ft.

The Spitfire data used in the following level speed chart derives from trials conducted by the Aeroplane and Armament Experimental Establishment (A.&A.E.E.) at Boscombe Down and the Royal Aircraft Establishment (RAE) at Farnborough. Spitfire Mk. I serial No. N.3171 first flew on 10 November 1939 and was delivered to A.& A.E.E. at Boscombe Down for flight trials on 16 November 1939. It was equipped with a Merlin III engine, Rotol Constant Speed Airscrew, bullet proof windscreen and domed hood. The A.&A.E.E. trials of N.3171 resulted in level speeds of 283 mph at sea level and 354 mph at 18,900 feet with the Merlin engine operating at 6.25 lbs/sq.in., 3000 rpm. 1d   For comparison, Spitfire Mk. I R.6774 equipped with de Haviland Constant Speed Airscrew and armoured windscreen achieved 288 mph at sea level and 355 mph at 17,800 using 6.25 lbs/sq.in., 3000 rpm. The similarly equipped Spitfire I R.6770, except fitted with 2 cannons and four Browning guns, reached 358 mph at 18,000 ft. 1e   The Royal Aircraft Establishment (RAE) obtained 314 mph at sea level and 359 mph at a full throttle height of 11,500 feet using +12 lbs/sq.in. boost. 1f

German data of the Me-109E shows top level speed ranging from 342 to 348 mph. Russian charts show top speed of the Me 109E-3 was 342 mph. French tests of a captured Me 109 returned maximum speeds ranging from 342 to 354 mph. (Il en résulte une incertitude sur les résultats: from estimated position error). 2a 2b 2c   Swiss full power horizontal flight speeds of a Me 109 with DB 601 Aa averaged 348 mph at 16,404 ft. 2d   US flight tests of an Me 109 E-3 operating at 1.3 ata obtained 290 mph at sea level and 339 mph at 17,500 feet. 2e   Some German documents suggest that mature Me 109Es having DB 601As with improved superchargers may have achieved 354 mph at 16,404 ft. All figures without armoured windscreen, excepting Russian where condition is unknown.

The Me 109 E data used in the following level speed chart derives from flight tests conducted by Messerschmitt at Augsburg and from the Bf 109 E Flugzeughandbuch. 3   Messerschmitt obtained 301 mph at sea level and 348 mph at 16,240 feet with ME 109 E-1 Wk.Nr. 1774 operating at 1.33 ata as recorded in Meßprotokoll vom 26.4.38. 4   The Me 109 Flight Handbook specifies the engine limits as 1.3 ata, 2400 rpm (1,3 ata und 2400 U/min nicht überschreiten!). 5   Trials of BF 109 E-1 W.Nr. 1791 by Messerschmitt as reported in Meßprotokoll vom 6.4.39 resulted in a sea level speed of 295 mph operating at 1.3 ata. 6   Trials of BF 109 E-3 W.Nr. 1792 by Messerschmitt as reported in Meßprotokoll vom 16.2.39 resulted in a sea level speed of 290 mph operating at 1.3 ata. 7   Messflüg vom 7.11.38, 1.3 ata, 5,653 lbs obtained 285 mph at sea level and 342 mph at 14,763 ft. Messung E.Stelle Bericht Nr. 2652/39 shows 280 mph at sea level and 342 mph at 14,763 ft. Recalculations of the test data at Augsburg from 14.10.39 gives 290 mph at sea level and 342 mph at 14,763 ft at 1.3 ata for a Me 109 E-3. Kontrollflug vom 31.4.39 at 1.3 ata shows 299 mph at 2,132 ft. (which extrapolates to about 290 mph at SL).

The comparable 5 minute engine limitations were; 1.30 ata/2400 rpm for the Me 109 E-1, 3 and 4, and +12 lbs/3000 rpm for the Spitfire Mk I. Comparitive speed trials carried out by the Royal Aircraft Establishment (RAE) at Farnborough found:

The Spitfire proved to be considerably the faster of the two, both in acceleration and straight and level flight, without having to make use of the emergency +12 boost. 8


The Spitfire data used in the following chart comes from A.& A.E.E trials of N.3171, the Me 109 data from the Flight Handbook - Dec. 1939. Neither data set includes pilot armour. Prior to the Battle of Britain operational Spitfires were retrofitted with pilot armour weighing 73 lbs. 117 117b 117c 117d   In addition, the Spitfire I 1/2 hour climb limit was raised to 2850 rpm below 20,000, 3000 rpm above 20,000. Combat climb rating was +12 lbs./sq.in, 3000 rpm.   Weight of the Spitfire I was 6,050 lbs, that of the Me 109 E1 5,672 lbs. and Me 109 E3 5,750 lbs. The DB 601A's supercharger was driven through a hydraulic coupling which is reflected in the 109 prototype level speed curve above and the engine curve below. (For more examples showing "proper" 109 curves see HERE). The BF 109 E Flugleistungskurven must thus be seen as somewhat simplistic.

F/O D. H. Watkins of 611 Squadron wrote in his Combat Report for 2 June 1940:

At 08.18 hrs 2 E/A Me109 sighted attempting to get on my tail - with emergency boost climbed away into sun - on turning saw two E/A crossing my path about 300 ft below flying line astern 200 yards apart - color silvery brown on top sides & fuselage - blue undersides and small black crosses. I attacked rear machine & opened fire from 200 yards on its starboard quarter - came into dead astern position at 200 yards and firing continuously saw parts of port wing break off - corrected aim and machine shuddered violently and did flat climbing turn and then dived vertically out of my sight. 9

P/O Peter St. John of 74 Squadron wrote in his Combat Report for 10 July 1940:

I was No. 3 in Yellow section patrolling over a convoy off Deal at about 10,000 ft. C.B.1200 visibility good. I sighted three enemy aircraft below and to the right. I informed Yellow leader of them; we went into line astern and went down to engage enemy aircraft. On the way down I saw another formation of 109's to the left and slightly down. Yellow leader had seen them also and we climbed and attacked from the rear. The 109's split up and I picked one and gave him a short deflection burst. I did not have time to see the effect of the burst as another 109 was on my tail. I outclimbed the 109 without difficulty. When I got on his tail I gave him all the ammunition I had and saw my tracers going in. The 109 flew off very unsteadily towards the French coast. Having finished all my ammunition I returned to Base. In my estimation there were about thirty 109's. I did not see any bombs. 10

F/LT John Ellis of No. 610 recorded in his Combat Report for 24 July 1940:

I was leading three sections of 610 Squadron on a patrol at 12,000' off Dover on 24/7/40. We took off at about 1115. At 1130 I sighted three Me 109's three thousand feet above us and flying west in the opposite direction to us. As I had to use full throttle to catch the e/a the remaining two sections got left behind. The formation of 109's broke up on being attacked and I singled out one of them. I opened fire at 200 yds. on the first burst and he immediately rolled on to his back and dived vertically, he then pulled out and proceeded to climb practically vertically. He carried out this manoeuvre four times and each time I got in a good burst while he was climbing. Throughout these evolutions bluish smoke was coming from a point about a foot from each wing tip. On his final climb I got in a good burst of roughly 5 seconds from dead astern, the Me 109 suddenly belched forth clouds of black smoke and white smoke, turned on its back and spiralled down in a vertical dive. It looked to be completely out of control. I followed the burning aircraft down until it entered a cloud at 3000' still going down almost vertically. F/O Wilson & Sgt Arnfield saw this e/a go down. 11

S/L John Ellis of No. 610 Squadron wrote in his Combat Report for 12 August 1940:

    I was leading 610 Sqdn which was detailed to intercept raid approaching Dungeness... In the dogfight I chased one solitary Me. 109 flying very fast and diving slightly. He rolled on to his back as I opened fire and I continued firing as he started his vertical dive, I could see my bullets entering the side of his fuselage as I followed him down. I broke off the attack as I was convinced he was diving out of control, he was also drawing away from me rapidly. F/O Lamb, who was behind me, later reported he saw this e/a continue its dive into the sea and break up.
    I climbed up again to 15,000 over Dungeness and spotted another Me 109 climbing into the sun. I caught him at about 20,000. He started to spin down to the left soon after I opened fire. I fired the remaining ammunition at very close range as he was spinning, but he presented an extremely difficult target. When I broke off the attack his engine was ticking over slowly and he was still spinning violently and he appeared to be out of control. Noticing a scrap going on just above I left the Me 109 and returned to re-arm. 12

Sgt. H. Chandler of No. 610 Squadron wrote in his Combat Report for 14 August 1940:

Attacked e/a which seemed to be above. Attempted to get on his tail, he immediately turned left to return the attack. We manoeuvered for a long while, during which he fired quite a fair amount. I got two short bursts which had no effect. After about 12-15 minutes he tried to out-climb me, I immediately went into fully fine pitch and easily caught up. The instant at which I opened fire, he rolled over and went straight down. I followed him and he started to smoke and eventually went into the sea. I steered 300° and after about 6-8 minutes made a landfall 3 miles West of Dungeness. 13

F/Lt. L. G. Olive of No. 65 Squadron recorded in his Combat Report of 13 August 1940:

At about 14.55 hours on the 13th August, 1940, "A" Flight took off to intercept 3 e/a flying from Chatham but no interception was made. On returning to land we were instructed to join up with "B" Flight which we did about 15.40. We intercepted about 15 to 20 Me.109's flying at about our own height (19,000 ft.) engaged about 5 with my section in a dog fight and noticed four above to the east at about 23,000. I climbed and after a dog fight shot down the rearmost which blew up and descended in flames. The remainder dived for France. I was then returning when I noticed four Me.109's at about 26,000 ft. I climbed and approached down sun and shot down another in flames. I saw it explode on the way down. I then started to descend when about 30 Me.109's tried to attack me, but as they were the same level I outclimbed them into the sun and attacked the nearest one of my pursurers. They gave up the chase and I was diving to cloud level when I saw a single Me.109 going back to France. I attacked at about 430 A.S.I. and fired about a four second burst and noticed him rock violently and pieces flew off the machine. I fired the remaining ammunition into him before he reached the cloud, when I lost sight of him. I then returned to Manston and landed. 14

F/Lt. L. G. Olive again noted that he out climbed Me.109s in his Combat Report of 24 August 1940:

At approximately 1530 I was patrolling with my flight following B Flight when we were instructed to intercept enemy raid. I saw about 40-60 bombers heavily escorted by fighters. Some of the fighters were above us. We climbed to 28,000 feet and attacked down sun. On my first attack I fired a full deflection on an Me.110 which immediately threw out clouds of white smoke, apparently Glycol. I last saw it diving about 10,000 feet below still throwing out smoke but could not observe it further as there were many e/a in the vicinity. I climbed above them and opened fire on the rear one which tried to fire from a gun in his tail. I could not observe the effect of my fire as I was being attacked by five ME 109's from above. I managed to out climb them and attacked the rear ME with my remaining ammunition but observed no results. Returned and landed. 15

P/O N. Agazarian of No. 609 Squadron wrote in his Combat Report for 26 September 1940:

I then climbed up to attack an Me 109 when I saw another diving past me - I turned and dived after it. It zoomed and I followed getting in a short burst from about 400 yards. I then gave my machine full throttle and revs and caught up the 109 hand over fist. When about 50 yards away and directly behind I gave him the rest of my ammunition. He went on to his back and spun down - I followed him down - the spin straightened out into a vertical dive so that I could not keep up with him. I lost interest and climbed up at about 3,000 ft. and went home. 16

F/Lt Eric Thomas of No. 222 Squadron wrote in his Combat Report for 9 October 1940:

I was leading the Squadron on patrol at 30,000 feet roughly over Chatham. I followed 41 Squadron down to 28,000 feet and then saw about 5 Me.109's directly above at 29,000 feet. I climbed up into them and they made for a layer of cirrus, through which I followed them. I increased revs. to 3000 and gradually outclimbed them and gave a 4 seconds burst into the belly of one enemy aircraft. Glycol streamed out of the port radiator and he went down in a shallow dive. I followed him down and gave a series of 1 second bursts at 100 yards, down to 3000 feet. During these attacks, glycol came out of the starboard radiator and black smoke came from the engine. The enemy aircraft landed with undercarriage up about 4 miles N. of Hawkinge, which burnt very slowly, a small amount of blue smoke coming out of the cockpit. Civilians then arrived and I saw them approaching the pilot, who was standing about 30 yards from his aircraft holding a white handkerchief and with his arms raised in surrender. The enemy aircraft had a completely yellow nose, cowling and rudder. 17


The first 77 production Spitfires were delivered with a fixed pitch, two-bladed wooden airscrew. As of May 1939, subsequent production Spitfires were fitted with the de Havilland two-pitch, three-bladed airscrew, which greatly improved take-off and high altitude performance. Deliveries of Spitfires equipped with constant speed propellers began as early as November 1939. No. 19 Squadron recorded their first delivery of the improved Spitfire as follows: 18

No. 54 Squadron completely converted to "Rotol Spitfires" during December 1939. 19 The introduction of the constant speed propellers increased the Spitfire's climb rate by 730 ft/min. over that of the 2-pitch propeller equipped Spitfires.

54 Squadron Spitfire I's equipped with Rotol Constant Speed Propellers and bullet proof windscreens. The Rotol CSP can be recognized by its more rounded spinner profile relative to the de Haviland propeller. KL/O is shown at Hornchurch. KL/T was flown by Colin Gray and is shown "somewhere in Essex, 1940". The camouflage and marking scheme, along with the condition of the aircraft, date the photographs sometime between March and May 1940.

Service trials at Hornchurch demonstrated that Rotol Spitfires had the following advantages compared to the de Havilland 2-pitch airscrews on Spitfires:- a better take-off; a better climb; a higher ceiling; much greater manoeuvrability; increased diving speed and increased endurance. Combat experience over Dunkirk also demonstrated that "The rotol Spitfire is the superior of any enemy aircraft yet encountered by our Pilots from Hornchurch". 19b  Hurricane squadrons were being supplied with aircraft fitted with Rotol constant speed airscrews during April and May 1940 and these aircraft were used on operations during the Battle of France. 19c 19d 19e 19f 19g 19h 19i   By June 1940 all Hurricane I aircraft being delivered from the manufacturers had Rotol constant speed airscrews. 19j   Those Spitfires previously delivered with de Havilland two-pitch airscrews were converted to constant speed units beginning in June 1940. 20 20b 20c 20d 20e 20f 20g 20h 20i 20j 20k   Conversion kits were also supplied to Supermarine for new production Spitfires. 21   The Spitfire I Pilots Notes (A.P.1565A) states:

Airscrew control.- This aeroplane may be fitted with one of the following airscrew controls: (a) de Havilland two position (b) de Havilland constant speed, or (c) Rotol (35°) constant speed. If constant speed control is fitted the r.p.m. can be adjusted to remain as desired, but within the limits allowed by the airscrew pitch range. If the two position control is fitted on this aeroplane it can also be operated to give various airscrew pitch settings between fine and coarse; this is obtained by slowly moving the control between its range of movement until the desired r.p.m. are obtained. For example, if a full power climb is required, instead of pushing the control into fully coarse pitch as the r.p.m. rise after taking-off, the control should be moved slowly forward until the r.p.m. drop to the maximum permissible for climb (2,600) and then pulled slightly back; this will leave the airscrew pitch at the position which gives these r.p.m. until power begins to drop off with altitude. As the power drops off the r.p.m. can be maintained by again fining the airscrew pitch as required. This in effect will give a similar improvement in performance to that obtained by means of a constant speed airscrew. The operation of varying the airscrew pitch in this manner to suit different conditions of flight will be found quite simple after a little experiment. 20l

Engine Power

Maximum power of the Merlin III was 1310 HP at 9,000 ft. (Emergency, 5 minute limit) and that of the DB 601 A, 1036 HP at 5,250 ft. (Kurzleistung, 5 minute limit). 22  23  23b  As the chart below demonstrates, the Merlin III was a more powerful engine at all altitudes compared to the DB.601 A, giving the Spitfire a clear advantage over the Me 109 E. The DB 601 A engine offered a number of advantages over the Merlin, however, such as fuel injection and better fuel consumption.

The Merlin III engine data is from Rolls-Royce. 24   The DB 601A engine data is taken from curves found in the DB 601 A u. B Motoren-Handbuch of May 1942. 25   Trials were successfully carried out in October 1939 to increase the power of the Spitfire's Merlin II and III engines by raising the manifold pressure to +12 lbs./sq.in. 26   Air Ministry A.P.1590B/J.2-W. dated 20 March 1940 gives official notice that "The emergency use of higher boost pressures up to +12 lb./sq. in. is now permitted for short periods by operation of the modified boost control cut-out". 27  Also during February and March 1940 Spitfire and Hurricane Squadrons were converting their aircraft over to 100 octane fuel, which made possible an increase in engine power by raising the boost to +12 lb/sq.in.. 28a  28b  28c  28d  28e  28f  28g  28h  28i  28j  28k  28l  28m  28n  28o  28p  28q  28r  28s  28t  28u  28v  28w  28x  28w  28z  28aa  28bb  28cc  28dd  28ee  28ff  28gg  28hh  28ii  28jj  Combat reports show that +12 lb boost was used by the Spitfire (and Hurricane) squadrons during their first combats with the Me 109 E in May 1940 while covering the Dunkirk evacuation. 29  30  Hurricane Squadrons based in France during May of 1940 were also employing +12 lbs/sq.in. boost in combat. 31   31b  

The first Spitfire into service was delivered to No. 19 Squadron at Duxford on 4 August 1938. The use of 100 octane fuel was approved for Spitfire Squadrons by 24 September 1938. 32   Fighter Command noted on 6 December 1938 that Duxford, Debden, Northholt and Digby had received 100 octane fuel. 32b   As of December 1938 Nos. 19 and 66 were based at Duxford and were the only RAF units then equipped with Spitfires. The Air Ministry noted in a memo dated 12 December 1939 that "100 octane fuel is approved for use in Hurricane, Spitfire and Defiant aircraft, and state that issue will be made as soon as the fuel is available in bulk at the distribution depots serving the Fighter Stations concerned." 32c   Gavin Bailey concluded that "The actual authorisation to change over to 100-octane came at the end of February 1940 and was made on the basis of the existing reserve and the estimated continuing rate of importation in the rest of the year." 33  As of 31 March 1940 220,000 tons of 100 octane fuel was held in stock. 34  The Co-ordination of Oil Policy Committee noted in the conclusions of their 18 May 1940 meeting with regard to the "Supply of 100 Octane fuel to Blenheim and Fighter Squadrons" that Spitfire and Hurricane units "had now been stocked with the necessary 100 octane fuel". 35   The Committee recorded that actual consumption of 100 octane for the 2nd Quarter 1940 was 18,100 tons. 36   Jeffrey Quill recalled:

It was only shortly before the Battle of Britain that we changed over to 100 octane. It had the effect of increasing the combat rating of the Merlin from 3000 rpm at 6 1/2 lb boost (Merlin III) or 9 lb boost (Merlin XII) to 3,000 rpm at 12 lb boost. This, of course, had a significant effect upon the rate of climb, particularly as the constant speed propellers (also introduced just before the battle) ensured that 3,000 rpm was obtainable from the ground upwards whereas previously it was restricted by the two-pitch propellers. It also had an effect upon the maximum speed but this was not so significant as the effect upon rate of climb. 37

Wood and Dempster wrote in their book "The Narrow Margin":

As it turned out, aviation spirit was to prove no worry for the R.A.F. By July 11th, 1940, the day after the Battle of Britain opened, stocks of 100 octane petrol used in the Merlin engine stood at 343,000 tons. On October 10th, twenty-one days before the battle closed, and after 22,000 tons had been issued, stocks had risen to 424,000 tons. With other grades of aviation spirit total stock available on October 10th, 1940, was 666,000 tons. Oil reserves were 34,000 tons. 38

Wood & Dempster’s figures for stocks of 100 octane are in agreement with those of the War Cabinet, however, their figure of 22,000 tons issued falls short of the Air Ministry’s figures as shown below. By 7 August 1940 "authority has been obtained for the use of 100 octane fuel in all operational aircraft and that instructions to that effect are being issued to Commands", i.e. all operational aircraft in Bomber, Coastal, Training and Fighter Commands. 39   100 octane fuel was the predominate aviation fuel in stock throughout the Battle of Britain. 40a   On October 29, just before the end of the Battle of Britain, 423,400 tons of 100 octane fuel was in stock in the UK. 40b   The War Cabinet recorded that 100 octane stocks stood at 202,000 tons on 31 December 1939 and that 100 octane stocks had risen to 499,000 tons one year later on 31 December 1940. 40c   The Air Ministry recorded that 58,000 tons of 100 octane were issued during the Battle of Britain. 40d   The War Cabinet recorded that 100 octane consumption within the UK for the whole of 1940 amounted to 130,000 tons, an average of 2,500 tons per week. 40e   Consumption of 100 octane during the Battle of Britain averaged 10,000 tons per month for the months of July and August rising to 14,000 tons in September followed by 17,000 tons during October. Total consumption of 100 octane fuel during the Battle of Britain therefore was on the order of 50,000 tons. 40f   V. A. Kalichevsky, author of the 1943 book The Amazing Petroleum Industry wrote:

It is an established fact that a difference of only 13 points in octane number made possible the defeat of the Luftwaffe by the R.A.F. in the Fall of 1940. This difference, slight as it seems, is sufficient to give a plane the vital "edge" in altitude, rate of climb and maneuverability that spells the difference between defeat and victory. 40g  

The Spitfire I Pilot's Notes lays out the use of +12 boost as follows:41

An August 1, 1940 memo from Air Chief Marshall Dowding to all Fighter Groups shows that the pilots often exceeded these limits.

The use of the automatic boost cut out control enables the pilot to get an emergency boost of + 12 lbs. per sq.in. from the engine for 5 minutes when circumstances demand it. Some pilots "pull the plug" with little excuse on every occasion. 42  

609 Squadron Spitfire I marked for 100 octane fuel  602 Squadron Spitfire I in pre Battle of Britain camoflage and marked for 100 octane fuel. 602 Squadrons's Operations Record Book notes for 16 February 1940 "100 octane fuel now in all aircraft"

Combat reports, official documents and literature of the period are replete with accounts of pilots using +12 lbs. emergency power, Hurricane as well as Spitfire, expressed variously as; breaking the wire, pulling the plug, pulling the tit, pushing the throttle through the gate, boost overide, boost cut-out, Emergency, Emergency power, etc. As Dowding noted above also with respect to the Defiant, the automatic boost cut out control enabled the pilot to get an emergency boost of + 12 lbs. per sq.in. A.&A.E.E tested the Defiant at +12 lbs boost and the pilots recorded pulling the boost cut-out. 42b   42c   The Spitfire Mk I Pilot's Notes shows the boost cut-out control adjacent to the throttle in the port view of the cockpit. 42d   Sectional perspective views of the automatic boost control can be found in AP 1590B Merlin II and III Aero-Engines. 42e   The control linkage for the automatic boost control system on the Spitfire I is shown in Air Publication 1565 A, The Spitfire I Aeroplane. 42f   As noted eariler A.P.1590B/J.2-W stipulated modification of the boost control cut-out to allow +12 lb./sq.in. boost pressures. 42g   DRG.No. A.P.1590B/J.2/40 showed where to drill a 0.093 in. hole in the cut-off valve for boost control to effect the modification. 42h

P/O John Freeborn of No. 74 Squadron used his boost cut out over Dunkirk on 24 May 1940:

As I broke away two ME.109's got onto my tail. I dived steeply with the 2 e/a following me, one was on my tail and the other on my port quarter. As I dived to ground level I throttled back slightly and the e/a on my tail over shot me and I was able to get a three seconds burst at a range of about 50 to 100 yards. He seemed to break away slowly to the right as though he was badly hit and I think he crashed. The second ME.109 then got onto my tail but I got away from it by using the boost cut out. 43

P/O Colin Gray (NZ), with No. 54 Squadron over Dunkirk, recalled the first time he used emergency power. Gray was engaged in a mêlée with Me 110s and 109s on 25 May 1940, when after destroying a Me 109 E and his Spitfire being hit by several cannon shells, he broke off combat:

By this time, as usual, there was not a soul in sight, and I decided the best course of action was to set off for home as speedily as possible. I pressed the emergency boost tit, which poured on the fuel, but was only for use in dire emergency as it could overstress the engine. I considered this was justifiable under the circumstances, since I was still inside France and could not see anyone coming to my assistance. 44

On another recounting of this incident Gray noted specifically "I selected +12 lbs (emergency boost) and continued my climb...". 44b   Gray also related a harrowing incident that occurred on 31 August when Hornchurch was bombed, the order given "54 Squadron, take off, take off, for Christ's sake take off", followed by section leaders ordering the Pilots to: "...press their emergency boost tits (giving double take off power)". 45

P/O Al Deere of No. 54 Squadron recorded in his Combat Report for 26 May 1940:

On approaching Gravelines at 17,000 feet two enemy aircraft were sighted. Red Leader and I gave chase using 12 boost. 29 

F/LT Brian Lane, serving with No. 19 Squadron, wrote of his 26 May 1940 combat wherein emergency power allowed him to escape a very dangerous situation indeed, his aircraft suffering only light damage:

I was beginning to breathe again when rat-tat-tat behind me and a tracer appeared over the cockpit, the bullets churning up a patch of foam in the water a hundred yards ahead. It was then that I remembered the automatic boost cut-out, a device giving maximum power from the engine for use in emergency. I pushed the lever down and felt the surge of power from the Merlin in front of me as the aircraft accelerated. Twisting and turning, I managed to keep clear of the Hun bullets, very nearly hitting the water several times while doing so. One of the 109s had evidently climbed up to one side and now came diving in at me from the beam. I turned towards him and gave him the last of my ammunition at point-blank range. I think he went straight in, for as I drew away with my superior speed I could see only two Messerschmitts behind me. 46

Of particular interest is Lane's official combat report of this incident, in which +12 boost is specifically mentioned:

            A dog fight now ensued and I fired burst at several E/A, mostly deflection shots. Three E/A attached themselves to my tail, 2 doing astern attacks whilst the third attacked from the beam.
            I managed to turn towards this E/A and fired a good burst in a front quarter deflection attack.
            The E/A then disappeared and was probably shot down. By this time I was down to sea level, and made for the English coast, taking violent evasive action.
            I gradually drew away from E/A using 12 lb. boost which gave an air speed of 300 m.p.h. 46b

19 Squadron Spitfire Mk I, spring 1940.

F/Sgt. G. C. Unwin of 19 Squadron recorded in his Combat Report for 1 June 1940:

I was Red 3 with F/Lt. Lane; along the coast, about 2 to 3 miles N.E. of Dunkirk 12 E/A were sighted at 4000 feet. We formed line astern and engaged the enemy. They formed line astern and used evasive action by turning. The aircraft looked like Me. Jaguars. I climbed underneath one and gave a burst approx. 5 secs. at 150 - 100 yds. range. The aircraft blew up over my head. I then chased another who turned and climbed as I got within range. I gave him a long burst, and his starboard engine then stopped and threw out oil and smoke. I carried on firing until about 100 yards, and then dived under him to avoid collision. I looked around for a while for more aircraft but could only see Spitfires. Being almost out of ammunition I returned home. Practically no return fire was experienced. Aircraft were fast. I had to use 12 Boost to catch them. No. of rounds fired - 300. 47

P/O M. P. Brown of 611 Squadron recorded in his Combat Report for 2 June 1940:

When patrolling Dunkirk at 15,000 feet with "A" Flight, ME.109's suddenly appeared in our formation. I attacked an ME.109 using deflection but no apparent hits. I then realized that an ME.109 was on my tail firing - I dived to evade e/a but was followed down by e/a. My engine was missing and I went down to beach, it picked up again and I went over Dunkirk at about 100 feet, still followed by E/A. When I opened the boost cut out I felt no more shots from e/a and found I had evaded him. 48

F/LT John Ellis of No. 610 recorded in his Combat Report for 12 June 1940:

I was the leader of Blue section 610 Sqdn. which was ordered to take off at 0745 hrs on 12/6/40. There were two aircraft in the section as Blue 3 had trouble starting and when he did take off he failed to contact us. Immediately we were airborne we were ordered to 'vector 120' and 'gate'. 49

610 Squadron Spitfire Mk I at Hawkinge in early July 1940. Note the petrol bowser marked for 100 octane fuel.

F/Lt. John Webster, of No. 41 Squadron, engaged in a night time interception of a He 111 at Tees Mouth recording in his Combat Report for 19 June 1940:

I was about 5 miles North East of A/C and chased after it. I had to use 12 lbs boost to catch it. 50

P/O J. P. Studd of No. 66 Squadron recorded in his Combat Report for 9 July 1940:

The enemy aircraft turned East and was caught after a chase of approx. 10 minutes, boost cut out being used. 50b

Sgt. A. Smith of No. 66 Squadron recorded in his Combat Report for 9 July 1940:

We gave chase using extra boost and climbing to height of 16000. 50c

F/Lt D. P. Kelly of No. 74 recorded in his Combat Report for 28 July 1940:

I was Blue No. 1 of No. 74 Squadron and was flying about 300 yards astern and to port of Red Leader when we saw some Me.109's a little below us (we were at 18,000 ft). Red section turned and dived down to port. I likewise turned to port but found a formation in Vic of 3 Me.109's pass about 300 yards across my nose. I took a snap shot at them but noticed no effect. Immediately after this I saw 3 Me. 109's to port diving down very fast. I found it necessary to use boost cutout and dived down on the leading one whom I managed to get on the tail of by diving steeply and turning left. I closed to 250 yards and opened fire with slight deflection and saw after a few seconds the machine turn left, dive and a tongue of flame appeared on port side. It then dived down into the sea burning. Blue 2 confirms that he saw smoke and glycol coming from enemy aircraft before he broke away to engage 2nd. enemy aircraft. 51

F/Lt. John Webster, of No. 41 Squadron, high-tailed it home using 12 boost on 28 and 29 July 1940, recording in his combat reports:

I returned home at 0 feet 12 boost, and landed at Hornchurch. 52

On reaching sea level I used twelve boost and made for the coast. Seeing that my aircraft was damaged I brought it back to Hornchurch. 53

P/O George Bennions, of No. 41 Squadron, engaged in a combat on 28 July 1940 demonstrating that emergency boost was used for offense as well:

...I ordered Yellow Section to carry out a Number One attack on this aircraft. Using the emergency boost I closed right in using full deflection and firing from 200 Yards to 100 Yards. The enemy turned over on its side and went almost vertically downwards, I followed using full boost and gave two more bursts of about 4 Seconds each from a position slightly left of astern, and after the second burst the whole of the enemy fuselage was enveloped in black smoke... 54

41 Squadron Spitfire I with F/O Peter Brown in the cockpit

P/O Art Donahue's account of using +12 boost during his first combat of 5 August 1940, whilst flying Spitfires with No. 64 Squadron out of Kenley, is typical:

“There are bandits approaching from the north” In quick response to this information, our leader sang out a command: “All Tiger aircraft, full throttle! Full Throttle!” That meant to use the emergency throttle that gave extra power to our engines. I was flying in our leader’s section, on his left. As he gave the command “Full throttle”, his plane started to draw ahead, away from me. I pushed in my emergency throttle in response to the command, the first time I had ever used it, and my engine fairly screamed with new power. I felt my plane speeding up like a high spirited horse that has been spurred. 55

F/Lt. John Webster, of No. 41 Squadron, once again noted use of 12 boost in his Combat Report of 8 August 1940:

I had no difficulty (using 12 boost) in overtaking the Me. 109's either in diving or level flight. 56

F/O R.W. Wallens, of No. 41 Squadron, recorded in his Combat Report for 11 August 1940:

12 lbs boost used by all Green Section. 57

41 Squadron, now flying from Catterick in 13 Group, intercepted the 15 August 1940 raid on the east coast. The Intelligence Officer noted:

All pilot's report e/a fast and used 12 lbs boost to catch them. 58

P/O Jeffrey Quill of 65 Squadron recorded in his book of a 12 August 1940 combat:

I pressed my boost control cut-out and felt the surge of power as the boost went suddenly up and black smoke poured from my exhausts. 75b

F/Lt George Gribble of 54 Squadron flying from Hornchurch, recorded in his Combat Report for 15 August 1940:

I dived to the attack, using 12 boost and fired a long burst at one from astern. It seemed to "shudder" in mid air and then dived away steeply with black smoke coming from it. 59

F/O Hugh Dundas (later Group Captain), flying Spitfires with No. 616 out of Leconfield, in the northern part of 12 Group, wrote of scrambling to intercept Ju 88s from Denmark on 15 August 1940 :

I set a course and rammed the throttle 'through the gate' , to get the maximum power output, permissible for only a very limited time. Some of the others were ahead of me, some behind. We did not bother to wait for each other or try to form up into flights and sections. We raced individually across the coast and out to sea. About fifteen miles east of Bridlington I saw them, to the left front, and slightly below - the thin, pencil shapes of German twin engine bombers, flying in loose, straggling, scattered formation toward the coast. 60

616 Squadron scramble from Kenley, late August 1940

F/Lt Robert F. Boyd, flying with No. 602 out of Westhampnett, wrote an interesting statement in his combat report for 18 August 1940 regarding emergency boost :

I then dived for sea level 10 miles from Coast, saw five aircraft I thought were Hurricanes and climbed to them for protection. They proved to be Me 109's which chased me back to coast, one continuing chase after others had left me: on seeing this I went into a turn, got onto its tail closed to 70 yards and fired 2 second burst. I saw this A/C hit the sea in flames... My Spitfire easily outdistanced Me 109's at 10 lbs boost 2800 r.p.m. 61

P/O James Morton, with No. 603 at Hornchurch, wrote in his diary for 28 August 1940:

We were now 3/4 way over the Channel, so I turned for home and dived to sea level. On the way down I noticed I was being followed so pressed the tit and kept very close to the water. The chap was 6-800' behind and I was slowly gaining. I kept on at sea level to the bottom of the cliffs near Hawkinge and came up and did a tight circuit of the old airship hanger, but the chap had gone. I felt rather relieved in the Channel as I thought most of my rounds were gone. Actually I had about 100 rounds left per gun. 'Tigger' (Morton's Spitfire) with the tit pressed and the dive from 4,000' was doing a steady 320 with a great long trail of smoke. I wonder if the Hun claimed anything. 62

P/O Ronald Berry of 603 Squadron shot down Oberleutnant Helmut Rau I/JG3 flying a Me 109 E-4 on 31 August, recording in his Combat Report:

As I had no oxygen, I had to leave the squadron at 22,000 feet and waited below in the sun for straggling enemy aircraft. After patrolling for 30 minutes, I saw a Me109 proceeding very fast. To overhaul him I had to press the emergency boost - indicated speed - 345. I caught the enemy aircraft off Shoeburyness. I opened fire at close range and fired all my ammunition until the enemy aircraft streamed with smoke and pancaked on the mud at Shoeburyness. 63

Sgt Jack Stokoe of 603 Squadron claimed a 109 destroyed, probably that of Oberleutnant Bauer of III/JG53, recording on his Combat Report of 1 September 1940:

At about 17.30 we were patrolling Manston at 12,000' when control informed us Canterbury was being dive bombed. About five miles south of the town when at about 3,000' a Me 109, silver with black crosses, dived past my nose flattened out about 50 feet up and headed south. I executed a steep turn, pushed in boost override, and sat on his tail. At about 50 yards, I gave him one small burst with little effect, closed to 30 yards, and gave a slightly longer burst. Black smoke poured from him as I overshot him. The a/c crashed in a field, turned over two or three times and burst into flames in a clump of trees. 70 bullets were fired from each gun. 64

222 and 603 Squadron Spitfires at Hornchurch, 1 September 1940

P/O Roger Hall of No. 152 Squadron based at Warmwell in 10 Group described a 4 September scramble:

We were traveling at full throttle and climbing at nearly three thousand feet a minute in the general direction of the enemy formation, which was just visible high up above and in front of us. I could see Yellow Section in front and above us also, going at full boost. Black streams of petrol vapour were coming away from their engines. ‘Better use your energy boost, Roger,’ Ferdie called out to me, as he started to increase speed himself. The makers stipulated that the emergency boost must not be used for more than five consecutive minutes, but now the occasion seemed to warrant the risk. I throttled back, pushed the red half-lever forward and then opened up the main throttle again. Immediately the aircraft seemed to leap forward with a jolt, hitting me in the back as it did so, and the engine started to vibrate – black smoke pouring out of each exhaust port. The engine vibration transmitted itself to the entire aircraft and I began to appreciate the maker’s instructions. 65

F/O Robert Oxspring (later Group Captain) of No. 66 Squadron, based at Kenley, wrote of a 6 September 1940 combat:

Still turning toward the bombers, I saw another 109 crossing ahead at my level. I throttled up to max power to reduce the distance and get my sights on. Just getting to firing range, I suddenly thought of Ken's 'watch your tail' warning. I looked back over my left shoulder and sure enough, another 109 was below my tail pulling bead and about to let go. There was no point in sticking around to see if he could shoot straight and my reactions were unbelievably fast. I parked everything in the left hand corner. Cranking on full left aileron and rudder, at the same time I shoved the throttle through the gate for emergency power.

Hauling back on the stick, I reefed into a blacked-out turn... I held the turn for a number of seconds which I judged had completed about 270 degrees... Then with the pressure relaxed my eyesight returned and I peered rearwards to seek my aggressor. He was nowhere in sight, but then nor was the rest of my flight.66

P/O R. D. Elliott of No. 72 Squadron, flying out of Biggin Hill, wrote on his Combat Report for 9 September 1940:

...I turned and was then astern E/A - & with the aid of MAX Boost (12 lbs) I gradually closed with enemy... 67

P/O H. R. Allen of No. 66 Squadron recorded in his Combat Report for 9 September 1940:

I intercepted using emergency boost. 67b

F/O Brian Macnamara of 603 Squadron recorded on his Combat Report of 27 September 1940:

I was Guard section leader when the squadron was proceeding north near Dungeness. I saw a 109 flying very low going south. I peeled off and chased it, firing continuously. I could see my incindiaries bursting on the machine and black smoke began to come from the engine and the enemy began to slow down and turn as if to land on the water. However two Me109's suddenly appeared 200 yards ahead of me out of the haze and shooting at me. I was forced to turn and run. The enemy chased me till I had crossed the English coast. I flew about 20 feet off the water, taking violent evasive action and the enemy's bursts missed mostly through insufficient deflection. In fine pitch, with full throttle and the red lever pressed, I appeared to be drawing away from the 109's as their fire slackened for the last mile of two and when I turned, they were further behind me than at the start of the action. 68

P/O Bob Doe described his usual routine after being scrambled, whilst flying Spitfires with No. 234 Squadron out of Middle Wallop, 10 Group:

Once we were in the vicinity of the enemy, I would 'pull the plug', which was the release so that we could get extra boost, but I wouldn't use it, and would start my search. 69

He had occasion to use emergency boost during a couple of low altitude tail chases of Me-109s, most notably whilst shooting down Hauptmann Rolf Pingell of I./JG26 on 18 August.

Geoffrey Wellum, flying with No. 92 Squadron out of Biggin Hill from early September to the end of the Battle, wrote of his routine when combat was imminent:

Things are starting to get rough. Automatically I have followed my self-imposed drill that I always do at times like this. Reflector sight on; gun button to fire; airscrew pitch to 2,650 revs; better response. Press the emergency boost override. Lower my seat a notch and strap tight. Ok men, I’m all set. Let battle commence. 70

P/O David Crook, with No. 609 Squadron at Middle Wallop, published an interesting account in his book of his most successful day of the Battle of Britain, 30 September 1940:

    It was now obviously a matter of moments only before we were in the thick of it. I turned my trigger on to 'Fire', increased the engine revs. to 3000 r.p.m. by slipping the constant speed control fully forward, and 'pulled the plug', i.e. pushed the small handle on the throttle quadrant that cuts out the automatic boost control thus allowing one to use emergency power.
    A few seconds later, about six Me. 109s flew across right in front of us. I don't think they saw us till too late as we were coming out of the sun. Michael was leading Blue Section and I was leading Green, and immediately we swung our sections round and turned on to the tails of the enemy. They saw us - too late - and tried to escape by diving.
    We all went down after them in one glorious rush and I saw Michael, who was about a hundred yards ahead of me, open fire at the last Messerschmidt in the enemy line. A few seconds later, this machine more or less fell to pieces in mid-air - some very nice shooting on Michael's part. I distinctly remember him saying on the R.T., 'That's got you, you bastard,' though he never recollects it!
    The victim that I had selected for myself was about 500 yards ahead of me, and still diving hard at very high speed. God, what a dive that was! I came down on full throttle from 27,000 feet to 1,000 feet in a matter of seconds, and the speed rose with incredible swiftness - 400 m.p.h., 500, 550, 600 m.p.h. I never reached this speed before and probably never shall again. I have a dim recollection of the sea coming up towards me at an incredible rate and also feeling an awful pain in my ears, though I was not really conscious of this in the heat of the moment. I pulled out of the dive as gently as I could, but the strain was terrific and there was a sort of black mist in front of my eyes, though I did not quite 'black out'.
    The Messerschmidt was now just ahead of me. I came up behind him and gave him a terrific burst of fire at very close range. The effect of a Spitfire's eight guns has to be seen to be believed. Hundreds of bullets poured into him and he rocked violently, then turned over on his back, burst into flames and dived straight down into the sea a few miles off Swanage. The pilot made no attempt to get out and was obviously dead. I watched him hit the water in a great cloud of white foam, and then turned round to see what else was going on.
    A few of our Spitfires were chasing Messerschmidts all over the place and obviously a very nice little massacre was in progress, as a few seconds later I saw another Hun go into the sea. I then saw another Me. 109 going back to France as hard as he could and I chased him, caught him fairly easily, and put a good burst into him. He swerved slightly, his cockpit covering broke off the machine and flew just past my head and he then dived steeply.
    I waited to see him hit the water, but he was only shamming, as he flattened out again just above the sea, and continued full speed for home, though his machine was now smoking and obviously badly hit.
    For the first time in this war, I felt a certain pity for this German pilot and reluctant to finish him off. From the moment I saw him, he had no chance of escape as my Spitfire was so much faster than his Messerschmidt, and the last few moments must have been absolute hell for him. I could almost feel his desperation as he made this last attempt to get away.
    But if I let him go, he would come back to England another day and possibly shoot down some of our pilots. In the few seconds during which all this was happening, I did not consciously make these reflections; my blood was up anyway and I was very excited, but distinctly remember feeling rather reluctant.
    However, I caught him up again and made no mistake this time. I fired all my remaining ammunition at very close range, and he crashed into the sea, going at a terrific speed, and disappeared immediately. I circled round the spot, but there was no trace of anything. 71

P/O David Crook in a 609 Squadron Spitfire takes off from Middle Wallop during September 1940
Crook's gun camera film from 30 September 1940 showing the Me 109 on fire and turning on its back just before diving into the sea

F/O D. McMullen with 222 Squadron at Hornchurch wrote on his Combat Report for 15 October:

I was leading the squadron, flying at 20,000 feet, when I saw two smoke trails approaching above me. I climbed and chased them same way. E/A then turned and came back through us. I engaged one E/A firing approximately one half my ammunition. Another Spitfire overshot me so I then engaged the second one. Both the E/A dived steeply towards cloud. I chased the second E/A at about 100 ft. out to sea over Hythe. Owing to the windscreen freezing up and extremely bumpy air I was handicapped. I overtook E/A easily without 12 boost. One piece of fuselage appeared to fall off. 72

P/O G. A. W. Bodie of No. 66 Squadron recorded in his Combat Report for 25 October 1940:

I followed using 12 lbs boost... 72b

The DB 601A data charted above comes from the DB 601 A u. B Moteren-Handbuch of May 1942, which includes a 1 minute take-off rating. The Betriebs und Wartungsvorschrift zum Mercedes Benz Flugmotor, DB 601 A u. B., Ausgabe C, October 1940 also notes a 1 minute take-off rating. 23c  The highest permissible values in climb and level flight were 1.3 ata and 2400 RPM. 23d  A clockwork mechanisim limited take off boost to 1 minute only.23e  The take-off rating was not mentioned in the Me 109 E Flugzeughandbuch; the maximum engine limits are stated as 1.3 ata, 2400 rpm.


The RAE determined in Report No. B.A.1640 that "The minimum radius of turn without height loss at 12,000 ft., full throttle, is calculated as 885 ft. on the Me 109 compared with 696 ft. on the Spitfire." and that the corresponding time to turn through 360 deg is 25 seconds for the Me 109 and 19 seconds for the Spitfire. 73   (See also Me 109 and Spitfire. Comparison of Turning Circles and Spitfire and Me 109 Diagrams of Turning). 60 years later Dr. John Ackroyd, PhD, C.Eng, FRAeS of the Aerospace Division, Manchester School of Engineering, University of Manchester, and Fellow of The Royal Aeronautical Society, took a fresh look at this subject in his paper "Comparison of turning radii for four Battle of Britain fighter aircraft". He calculated the minimum turn radii to be 686 feet for the Spitfire IA versus 853 feet for the BF 109 E-3 - which is in very good agreement with the RAE's findings. 74  

Jeffrey Quill wrote of his combat experience whilst flying with No. 65 Squadron:

Nearly all our engagements with Me 109s took place at around 20,000 - 25,000 ft. The Spitfire had the edge over them in speed and climb, and particularly in turning circle. (...) One engagement with several Me 109s at about 25,000 ft over the Channel sticks in my memory. It all happened very suddenly; in fact we were mildly 'bounced' and soon I found myself behind two 109s in a steep left-hand turn. I was able to turn inside the second one and fired at him from close range. He went on pulling round as sharply as he could. I followed him without any difficulty and went on firing bursts at him. There were puffs of black smoke and then a trail of white vapour streamed from his aircraft. By this time I could no longer see the first 109 and then realized that he was on my tail. As I was by now just shuddering on the verge of a g-stall, I quickly turned inwards and dived. I pulled up again when I was sure I had shaken him off... I was pleased with that little episode – partly because I was damn sure that the first 109 was not going to get home and also because I was now convinced that the Spitfire Mk I could readily out-turn the 109, certainly in the 20,000 ft region and probably at all heights. 75

F/Lt Al Deere (NZ), with No. 54 Squadron during the Battle of Britain, commented:

My experience over Dunkirk had taught me that when attacked the best counter was to go into a right turn. In this manoeuvre, the Spitfire was infinitely superior to the Messerschmitt, and so long as one remained in the turn, the enemy pilot could not bring his guns to bear. And this I did, as the German pilot flashed past, turning as he did so to get behind me. But it was I who finished astern of him. The rest was easy. 76

F/Sgt William H. Franklin of No. 65 Squadron recorded in his Combat Report for 25 June 1940:

65 Squadron on offensive patrol North of Abbeville sighted about 12 ME.109 at about 15,000 feet. We attacked per section, I was Blue 2. An enemy aircraft circled on to my sections tail and I broke away to engage, but Blue 3 got there before me. I was then attacked by 2 enemy aircraft, and turned sharply to get on the tail of one. I manoevured into position on his tail and fired a very short burst at about 200 yards. Enemy aircraft burst into flames and dived vertically. I was now engaged by second enemy aircraft. I manoevured onto his tail, as 2 other enemy aircraft attacked me from the rear. I broke away and after considerable manoevuring we had lost height to 4000 feet. One Me.109 again attacked from behind but I was able to turn slightly and get on his tail. I followed him as he turned and seeing me closing on him he half rolled. This brought the other two aircraft out of position for attack on me. I followed inside the first enemy aircraft and fired two very short bursts at about 250 yards and I saw enemy aircraft dive into the ground. 77

F/LT John Ellis of No. 610 may have learned from Deere's experience, recording in his Combat Report for 24 July 1940:

I was the leader of 610 Sqdn. which was sent to attack e/a attacking shipping N. of Margate on 24/7/40. The Squadron left Hawkinge at 1230 and climbed through 3,000 ft of cloud which was down to 400' over the aerodrome. We came out of the cloud over Margate and as we had penetrated the cloud by sections I gave orders for the sections to rendezvous over the convoy which was 5 miles N. Margate. While circling the Convoy Green 1 called me up to say he was on my starboard beam and below. I sighted green section immediately but at the same time saw three Me 109's diving down in vic to attack them so I gave orders for green section to do a tight a turn as possible to the right this they did and successfully evaded the enemy who had just commenced to open fire as they turned. Blue Section immediately attacked the 109's which broke up two diving down and one climbing. I attacked the one that climbed, closed to 250 yds and fired two bursts of roughly 6 seconds closing eventually to 50 yds. The e/a was enveloped in black & white smoke after the first burst and it eventually rolled on its side and dived straight down and crashed into the sea eight miles N.N.E. Margate. This is confirmed by F/O Wilson & Sgt Arnfield. 78

610 Squadron Spitfires over Kent, June 1940

P/O Art Donahue, an American serving with No 64 Squadron, described his 8 August combat with a Me 109:

Then one got on my tail and gave me a burst just as I saw him, and I laid over into a vertical turn; and as he did likewise, following me, I hauled my Spitfire around as tight as I could. We were going fast and I had to lean forward and hold my breath to keep from blacking out, and I turned this way for several seconds. Then I eased my turn so that I could straighten up and look out my cockpit, and I spotted the other in front of me. I had turned around on his tail now. He apparently became aware of it at the same time, for he abandoned his turn and took to flight; but he was a little late now. 79

P/O D. Hastings of No. 74 Squadron recorded in his Combat Report for 11-8-40:

I was Red No. 3 of No. 74 Squadron on patrol over Dover at about 24,000 feet. A.A. fire at 25,000 feet gave indication of bandits, and I saw 8 fighters to port. Red leader gave chase and dived after M.E. 109. I followed in line astern, Red Leader dived to about 5,000 feet towards the French coast. As no further E/A were near I went to the aid of a Spitfire who was engaging another M.E. 109, but which had a further M.E. 109 on its tail. I engaged the later E/A and gave it a 2 seconds burst at 300 yards range which immediately caused him to cease fire and he broke away to starboard. I followed him round and gave two 4 seconds deflection shots, this caused a stream of white liquid to pour from him. I then broke off as another M.E. 109 was closing in on my tail and firing at about 250 yards range.
      I found that with full throttle and 2800 revs. I did a steep climbing turn to starboard which easily out-turned the M.E. 109. They had the usual silver grey camouflage and black crosses and were apparently working in pairs. 80

F/O William Nelson D.F.C., an American in the R.C.A.F. and serving with No. 74 Squadron, recorded in his Combat Report for 11-8-40:

I was yellow 3 in No. 74 Squadron, on patrol over Dover at about 24,000 feet and sighted 8 M.E. 109s's to port. My leader suddenly dived on one ME 109, so I circled looking for any E/A coming down on our section. While climbing and turning I saw 6 M.E. 109's at 28,000 feet who obviously did not see me, they were circling widely so I climbed onto the last E/A. I was sighted and they started turning steeply, I easily out-turned them. They all broke up and the last E/A flich-rolled away from me, I closed rapidly and at the short range of 150 yards I opened fire with a 3 seconds burst dead astern, and he burst into flames. I immediately turned quickly away and saw the remainder E/A speeding for home, well away. Not seeing any further E/A I pancaked Manston. The M.E. 109's were sky - blue beneath and ordinary camouflaged above with black crosses. 81

F/Sgt William H. Franklin of 65 Squadron recorded in his Combat Report of 16 August 1940:

The squadron was operating from Manston and ordered to patrol Deal at 16.17 hours. We first sighted numbers of enemy fighters high above and climbed to engage. I suddenly found myself passing straight through a compact formation of about 24 Heinkel 113. Two end He.113's engaged me firing deflection shots. The shooting was bad, all going astern, and it struck me that they could not turn very quickly. In the ensuing fight I had no difficulty in firing a short burst from astern which sent one e/a down in flames. The others vanished. I ended in mid-channel and after a few minutes saw below me a Dornier 17 followed by a Me.109 well astern going towards France. I dived from about 20,000 feet down to 6,000 feet and closing in, fired a good burst from astern into the Do.17. It blew out grey smoke from both motors and bits came off the fuselage. I then had to attend to the Me.109 which dived towards Inglevert aerodrome. At 1,500 feet I fired a 3 second slight deflection shot and the e/a crashed into the ground off Inglevert. I then returned to base. 82

S/P Andrew McDowall, flying with No. 602 Squadron, recorded his opinion in his Combat Report for 18 August 1940:

In this dogfight I was able to get a long burst at one Me 109 and saw it crash into the sea... In my opinion Me 109's cannot hit Spitfires in tight right hand turn because they can't turn inside you in stern attack. 83

602 Squadron Spitfire I at Westhampnett in August 1940

Sgt N. Ramsay of No. 610 Squadron recorded in his Combat Report for 26 August 1940:

I was Green 2, and we were flying at 12,000 feet when the leading section dived to attack some E/A over Folkestone. My leader saw aircraft above and did not follow down. He ordered 'line astern' and started turning in a circle. I saw E/A coming down at different angles, one came down astern with me. I turned very steeply to the left, and eventually got on to his tail, he started turning left and right and I fired three short bursts. On the last burst he emitted a cloud of black smoke and started spiralling down very fast. As he went down the smoke ceased and he vanished into the cloud looking very much out of control. I did not go through the cloud immediately because I wanted to see if there were any more E/A near me. There were some above, but I decided they were too high so I went through the clouds and saw an E/A blazing on the ground West of Folkestone. 84

P/O Ronald Berry of 603 Squadron used the Spitfire's turning ability to transition from evasion to attack, recording in his Combat Report for 28 August 1940:

When approximately over Dover, the Squadron split up on sighting several Me.109s. Looking above 3 Me.109's crossed my bow in line astern. Shortly after, on my beam. Me.109 was firing and I immediately whipped up my aircraft and round and found myself on his tail, and at close range pumped lead into it until it opened into a heavy cloud of smoke. On turning again, another Me.109 was attacking from quarter astern. I steep turned to the right and got on his tail and he dived. I followed him and attacked, some bits fell off from E/A. As my ammunition was expended, I broke off combat and returned to base. 85

Sgt R. Hamlyn of 610 Squadron recorded in his Combat Report for 30 August 1940:

I was Green Leader. I first sighted enemy aircraft over Ashford and started to attack them but a number of M.E. 110's attacked me before I could open fire. So I eventually fired at one of the M.E's. He fell away from the rest, but I could not possibly see any result owing to the other enemy aircraft. On returning to base at 1,000 ft I noticed more aircraft bombing Biggin Hill. I at once climbed up to about 20,000 ft and was attacked by 5 M.E. 109's which were circling. Owing to my slow speed I was easily able to get on the tail of the last 109. I fired a burst of about 2 seconds from astern with slight deflection. He fell away from the others smoking badly. I followed him and gave him the rest of my rounds in one burst. He went straight in the ground. I came down to the place I thought I had seen him hit and there was a large fire burning in the wood round West Malling aerodrome. 86

Sgt B. Douthwaite, of 72 Squadron, recorded on his Combat Report for 2 September:

I then turned to port and attacked an Me 109 who was turning steeply to port. I could easily out turn him and fired until he broke away in a steep left hand dive. As I had expended my ammunition I did not follow him but returned to Hawkinge. 87

S/L Brian Lane, of No. 19 Squadron, got into a tight turning fight with an Me 109 on 15 September 1940:

That German pilot certainly knew how to a handle a 109 - I have never seen one thrown about as that one was, I felt certain that his wings would come off at any moment. However, they stayed on, and he continued to lead me a hell of a dance as I strove to get my sights on him again. Twice I managed to get in a short burst but I don't think I hit him, then he managed to get round towards my tail. Pulling hard round I started to gain on him, and began to come round towards his tail. He was obviously turning as tightly as his kite could and I could see that his slots were open, showing he was nearly stalled. His ailerons were obviously snatching too, as first one wing and then the other would dip violently. Giving the Spitfire best, he suddenly flung out of the turn and rolled right over on his back passing in front of me inverted. ...he flew on inverted for several seconds, giving me the chance to get in a good burst from the quarter. 88

F/S George Unwin, also of No. 19 Squadron, recalled his combat of 15 September:

Anyway I went into a tight turn and stayed in it and there, I don't know how many of these aircraft there were, I shot at several of them as they went through my sights but I actually shot two of them down. One of them strangely enough, I fired at the first one, I got the first one, and he bailed out. And of course the Messerschmitt pilot unfortunately sat on his tank, did you know that? He sat on his petrol tank and it wasn't a very, if they got a bullet there - up it went. This chap bailed out and I went to sight the next one, when suddenly the light - the reflector sight was an electric bulb lit up, and the bloody bulb failed. So I am without a sight but we did have this ammunition so the next one I got, I was still in a tight turn all the time, I mean, that was what probably saved me, you kept on turning and turning. Because the Messerschmitt couldn't turn like a Spitfire and I kept on turning, I don't know how many aircraft there were and the second I shot down without a sight. It was really wild and, you know, the fall off on the trace of a bullet and I got him exactly the same way, his tank went up but that frightened me I can tell you. I was all on my own in the middle of, I don't know how many, how many Messerschmitts there were but fortunately, as I say, I got away with it. I didn't even get a hole in me that day and yet against the odd ones I have several times got holes in me, but that day I got away with it. I must have had a guardian angel with me that day. 89

Unwin, also recounted:

I had survived this mission simply because the Spitfire could sustain a continuous rate of turn inside the BF 109E without stalling - the latter was known for flicking into a vicious stall spin without prior warning if pulled too tightly. The Spitfire would give a shudder to signal it was close to the edge, so as soon as you felt the shake you eased off the stick pressure.

19 Squadron Spitfire Mk I at Fowlmere in September 1940.

F/Lt J. W. Villa of No 72 Squadron recorded on his Combat Report for 15 September:

The ME 109 which I attacked half rolled as I opened fire and before he could dive away he caught fire and exploded. I was then attacked by five other ME 109. I did a steep turn to starboard and continued to turn until I out turned one ME 109 which was on my tail. I gave him two short bursts and he burst into flames. 90

Geoffrey Wellum of No 92 Squadron found himself in quite a fix after expending all his ammunition shooting down an HE-111:

I've behaved like a beginner, bounced from behind. My own fault, shouldn't have relaxed after I'd finished with that bloody Heinkel. Elementary rule number one: never relax vigilance. I asked for it and got caught napping, well and truly bounced...

Looking back over my shoulder, an Me 109 is sitting on my tail not thirty yards away, or so it seems, and turning with me. I see the flash from his cannons and puffs of greyish smoke as he tries a quick burst. Not a bad one either as I hear more hits somewhere behind the fuselage.

The German pilot is trying to tighten his turn still more to keep up with me and I'm sure I see the 109 flick. You won't do it, mate, we're on the limit as it is. I can see his head quite clearly and even the dark shape of his oxygen mask. Yet again I imagine that the 109 gives a distinct flick, on the point of a high speed stall. He has to ease his turn a fraction. The Spitfire gains slowly. I exalt and yell at him. Sweat starts to get into my eyes...

The 109 finally comes out of his turn and pulls up, trying to gain height on me. As he climbs he goes into another steep turn, very steep, well over the vertical. I look up at him but he has made his effort and failed. I've gained too much and now I'm more behind him than he is behind me...

If you want to shake someone off your tail you have to fly your Spitfire to its limits. In a tight turn you increase the G loading to such an extent that the wings can no longer support the weight and the plane stalls, with momentary loss of control. However, in a Spitfire, just before the stall, the whole aircraft judders, it's a stall warning, if you like. With practice and experience you can hold the plane on this judder in a very tight turn. You never actually stall the aircraft and you don't need to struggle to regain control because you never lose it. A 109 can't stay with you. 91

P/O George Bennions, of No 41 Squadron, demonstrated that the Spitfire was especially effective against the Me 109 when the turn was combined with a steep climb:

As Mitor Red 2 in line astern of Red 1 while acting as rear guard to blue and green sections, I noticed 2 ME 109's above and to the right diving to attack Red 1. I warned Red 1 and we turned right to evade them. We then turned left behind them to engage them. Half way around the turn I noticed another ME 109 about 800 yards astern and to the left. I immediately went into a steep right hand climbing turn at full throttle. The ME 109 tried to follow but after about 2 turns he fell out of the turn completely stalled, and I turned down on his tail. He carried out a left hand climbing turn and he ded S.E. at full throttle. I immediately closed astern but slightly left and opened fire at approx 100 yards. After two very short bursts I observed coolant pouring from the radiator... 92

Leading Blue Section I was attacked by ME 109. After a steep right hand climbing turn the ME 109 with a Yellow nose fell out of the turn and I turned on to his tail. He rolled over and went vertically downwards and pulled out heading south east as soon as he straightened up. I gave him three short bursts. He burst into flames and after knocking off his roof bailed out. 93

Evidently Bennions was well schooled in tactics arising from the RAE's comparative trials, where it was determined that:

Another effective form of evasion with the Spitfire was found to be a steep, climbing spiral at 120 mph, using +6 1/4 boost and 2,650 rpm; in this manoeuvre, the Spitfire gained rapidly on the ME 109, eventually allowing the pilot to execute a half roll, on to the tail of his opponent. 94

Sgt. Jack Stokoe of No 603 Squadron found the Me 109s to be vulnerable when they tried to use the spiral climb as an evasion, recording in his Combat Report of 31 August 1940:

We were ordered to patrol base at 12,000 feet. As I was rather late, the formation took off without me. I took off alone, climbed into the sun, and rejoined the formation which was circling at about 28,000 feet. I observed 2 Me 109s above, and climbed after them in full fine pitch. The ME's kept close together in a steep spiral climb towards the sun. I pumped several bursts at the outside one from about 200 yards with little effect. I closed to 50 yards and fired two more long bursts. Black smoke poured from his engine which appeared to catch fire, and 8 or 9 huge pieces of his fuselage were shot away. He spun steeply away and crashed inside the balloon barrage. I continued climbing after the other ME 109, and fired two long bursts from about 150 yards. White smoke came from his aircraft, and he spiralled gently downwards. I broke away as I was out of ammunition, and failed to see what happened to him. 95

P/O J. G. Drummond of 92 Squadron recorded in his Combat Report for 24 September 1940:

As leader of Blue Section 92 Squadron we intercepted enemy aircraft South of Estuary in the Maidstone area. I did a beam attack on the rear Section of Ju. 88's from below and right and fired a 3 second burst and hit the Port engine. After breaking away from the 88 I did a steep turn and found 3 Me. 109's on my tail. I turned on to the tail of the rear Me. 109 and fired a 5 second burst at about 300 yards from the quarter. Clouds of white smoke indicated that I had hit his glycol. I turned round and fired at another 109 which was on my tail. I saw my bullets hit the enemy aircraft. I then broke away and dived for the ground. 96

P/O D. C. Winter of No. 72 Squadron used a descending spiral turn as an effective evasive:

Then six more Me 109's came down on me & as I turned port an He 113 pulled up in front of me & I had a good bead for about 2 secs. during which time I was firing. The He 113 turned over & dived seawards... By then I was being attacked by six more Me 109 & by doing steep spiral turns I managed to avoid their fire. After awhile I saw the He 113 I had shot at, plane down into the water & sink about 2-3 miles off Beachy Head. This was confirmed by Red 3. Meanwhile I was still spiralling steeply & the Me 109's followed me down to about 1,000 ft & then I got down to about 50 ft & they left me. It was impossible to get a bead on them owing to their numbers. 97

Sgt P. Else of No. 610 Squadron also used a diving turn to good effect, recording in his Combat Report for 25 July 1940:

I was flying No. 2 position in Blue section when we sighted about 20 or more Me 109's above about 12 JU 87. We climbed in line astern to attack the ME and fired at one with considerable deflection with no result. I then had to shake off one Me 109 off my tail which I did with comparative ease with a tight diving turn. I then found myself on the edge of the mellee and slightly on the starboard rear beam of two ME 109's flying in line astern.
I attacked the rear machine from the quarter closing to astern opening fire at 200 yds and closing at about 25 yds. I could see the explosive bullets from my guns hitting him in the rear of the fuselage and the tail unit.
As I broke off the attack owing to the danger of hitting him he fell on one side, evidently from the attitude the machine had adopted, out of control. Both Me 109's took no evasive action at all, as I caught them both by surprise. The Me 109's were definitely working in pairs. I also saw one Me 109 shot down by F/Lt Ellis. 98

P/O Colin Gray (later Group Captain) of No. 54 Squadron reflected:

The problem of manoeuvrability was of prime importance in enabling one to turn inside the enemy, certainly in fighter versus fighter combats, and thus to get a shot in when on attack, or avoid being shot down when on the defensive - and here the British aircraft had a decided advantage in my experience. 99

F/O Hugh Dundas, with No. 616 during the Battle, wrote:

In one vital aspect the ME109 was at a disadvantage against the British airplanes. It could be out-turned both by the Spitfire and the Hurricane. This was a serious handicap to the Luftwaffe pilots allotted the duty of providing close escort for the bombers. Their freedom of action was curtailed. They could not pursue the tactic, best suited to their planes, of a high-speed attack followed by dive and zoom. They had to stick around and fight it out; and that involved the matching of turning circles. They never found a way round that problem and their difficulties were made all the greater when Goering, infuriated by the losses inflicted on his bombers, ordered the fighter squadrons to cling ever closer to the bombers they were escorting. 100

Adolf Galland recalled a conversation with Göring in August 1940:

I tried to tell him otherwise, replying that the Spitfire was better able to reduce speed, because of its lower wing loading. It was also better able to turn at low speeds. 101

Heinz Knoke was still flying a Me 109 E4 with II/JG 52 over England in May 1941 when he wrote of the Spitfires he encountered:

The bastards can make such infernally tight turns; there seems to be no way of nailing them. 102

The War Diary of I/JG 3 entry for 31 August 1940 states:

The Spitfires turn very well even at higher altitudes and tighter than the Bf 109. 103

Roll Rate

The RAE reported: "At 400 m.p.h. the Me.109 pilot, pushing sideways with all his strength, can only apply 1/5 aileron, thereby banking 45 deg. in about 4 secs.; on the Spitfire also, only 1/5 aileron can be applied at 400 m.p.h., and again the time to bank is 45 deg. in 4 secs. Both aeroplanes thus have their rolling manoeuvrability at high speeds seriously curtailed by aileron heaviness." 104

Elevator:-  The BF 109E flight handbook states: "Die Höhenruderkräfte und Flossenbelastungen werden bei hoher Fahrt sehr groß." 105 (The elevator forces and fin loads become very large during high speed). The RAE also found the 109's elevators to be heavy: "Throughout the speed range the elevator is heavier than that of the Hurricane or Spitfire, but up to 250 m.p.h. this is not objected to, since it is very responsive. Above 250 m.p.h. the elevator becomes definitely too heavy for comfort, and between 300 m.p.h. and 400 m.p.h. is so heavy that manoeurvability in the looping plane is seriously restricted; when diving at 400 m.p.h. a pilot, pulling with all his strength, cannot put on enough "g" to black himself out if trimmed in the dive." 106   It was found that the Spitfire pilots were able to evade Me 109's by "doing a flick roll and then quickly pulling out of the subsequent dive", and "if a Me.109 pilot can be tempted to do this at low altitude a crash is almost inevitable". 107  F/Sgt. Tew, of No 54 Squadron, put this tactic to good use, being credited with 1 Me. 109 destroyed without firing a shot:

During Patrol at approximately 1300 hours on 18/8/40 I was attacked by one Me 109 when I was at 2,000 feet. I turned towards enemy aircraft in a diving turn. Enemy aircraft half-rolled and followed me. I pulled out of dive at low altitude but enemy aircraft continued his dive and struck the ground bursting into flames. 108  

The Spitfire on the other hand was known to have a sensitive elevator control, perhaps a bit too sensitive.

Aerobatics:-  The RAE's view on the Me 109E's aerobatic capability:

Aerobatics are not easy on this aeroplane. Loops must be started from 280 m.p.h. when the elevator is unduly heavy; there is a marked tendency for the slots to open near the top of the loop, resulting in aileron snatching and loss of direction, and in consequence accurate looping is almost impossible.

At speeds below 250 m.p.h, when the ailerons are light and very effective, the aeroplane can be rolled very quickly, but there is a strong tendency for the nose to fall in the final stages of the roll, and the stick must be moved well back in order to keep the nose up.

Upward rolls are difficult; the elevator is so heavy at high speed that only a gentle pull-out from the preliminary dive is possible, and a considerable loss of speed is thus inevitable before the upward rolls can be started. 109

The Spitfire I's Pilot's Notes states:

This aeroplane is exceptionally good for aerobatics. Owing to its high performance and sensitive elevator control, care must be taken not to impose excessive loads either on the aeroplane or on the pilot and not to induce a high-speed stall. Many aerobatics may be done at much less than full throttle. Cruising r.p.m. should be used, because if reduced below this, detonation might occur if the throttle is opened up to climbing boost for any reason. 110

Leutnant Hans-Otto Lessing of II.JG/51 observed in a letter to home written 17 August 1940:

During the last few days the British have been getting weaker, though individuals continue to fight well. Often the Spitfires give beautiful displays of aerobatics. Recently I had to watch in admiration as one of them played a game with thirty Messerschmitts, without itself ever getting into danger; but such individuals are few. 111

Leutnant Max-Hellmuth Ostermann of 7./JG 54 wrote in his diary for 31 August 1940:

Utter exhaustion from the English operations has set in. Once more I lost contact with my squadron. The Spitfires showed themselves wonderfully manoeuvrable. Their aerobatics display - looping and rolling, opening fire in a climbing roll - filled us with amazement. I did no shooting but kept trying to get into position, meanwhile keeping a sharp watch on my tail. 112

S/Ldr. Leathart of No 54 Squadron put the Spit's capabilities, as well as his own, to use on 2/9/40 when he "played a game" with the Me 109s:

I was caught at a disadvantage about 4/5,000 feet below two squadrons of Me 109's. I decided that the best thing to do would be to act as a decoy. I harassed them and weaved among them and ended up getting them about 20 miles away from the aerodrome and North of Rochford. 113


Major Werner Mölders, JG 51, compared the British fighters to his own prior to the Battle:

    It was very interesting to carry out the flight trials at Rechlin with the Spitfire and the Hurricane. Both types are very simple to fly compared to our aircraft, and childishly easy to take-off and land. The Hurricane is good-natured and turns well, but its performance is decidedly inferior to that of the Me 109. It has strong stick forces and is "lazy" on the ailerons.
    The Spitfire is one class better. It handles well, is light on the controls, faultless in the turn and has a performance approaching that of the Me 109. As a fighting aircraft, however, it is miserable. A sudden push forward on the stick will cause the motor to cut; and because the propeller has only two pitch settings (take-off and cruise), in a rapidly changing air combat situation the motor is either overspeeding or else is not being used to the full. 114

Fortunately for Spitfire pilots, the two-pitch propeller was not representative of the condition of their aircraft during the Battle of Britain. New production Spitfires were delivered with constant speed propellers beginning in November 1939 and those older Spitfires with two pitch propellers underwent a crash program in June 1940 to have constant speed units retrofitted. 115 116 116b 116c 116d 116e 116f   Another modification to the Spitfires undertaken just prior to the Battle which proved to be of immense value to its pilots was the addition of armour plating behind the pilot's seat. 117 117b 117c 117d   Without doubt the Daimler-Benz performed better than the Merlin under negative 'g', however, it was not without its own limitations: Motor und Triebwerksanlage des Flugzeuges sind nicht zur Durchführung von rückenflügen geeignet. Hingegen ist Motor und Triebwerksanlage geeignet für Kunstflug in jeder anderen Form, wo nur ganz kurzzeitige Rückenlagen in Verbindung mit anderen Flugfiguren verkommen. Had the Rechlin test used the 100 octane fuel available to the British and had the tested Spitfire incorporated the latest improvements, Mölders would have seen the British fighters to be much more formidable opponents than those examples tested by the Germans which crashed during the Battle of France. Given that Mölders was injured and forced to crash land when his 109 was shot up by a Spitfire on 28 July 1940, and his plea to Göring in August for "a series of ME-109s with more powerful engines", its likely he held revised views of the Spitfire during and after the Battle of Britain.118

Oberleutnant Ulrich Steinhilper of III/JG 52 wrote of the difficulties new pilots found operating the Me 109's propeller:

We began our climb almost immediately after take-off and he was constantly using the radio to ask us to slow down so that he could keep up. It was obvious that he wasn't manipulating the pitch control with the skill of the more seasoned pilots to produce the same power as our machines. We tried to tell him what to do on the radio but to no avail. Eventually, about half way across the Channel at 4,000 metres Kühle told him to leave the formation and return to base. 119

Leutnant Erich Bodendiek, II/JG 53 engaged in a 18 September combat which demonstrated that the Me 109's propeller could be troublesome:

I was not flying my usual plane but, as I was the Technischer Offizier, I had to fly a plane with a new automatic propeller just to test it. That was my bad luck, having that bloody plane on that day for the first time because that 'automatic thing' turned that angle of the propeller so that an average speed was always maintained and not a kmh more! That meant trouble when starting and trouble at high altitude as the plane was nearly always unmanoeuvrable and swaggered through the air like a pregnant duck.

It was fine weather with clouds at an altitude of about 8,300m and out of this swung the RAF fighters when we were at 8,000m. They were obviously directed by radar but just missed us as they came out of clouds about a kilometre to the right of us. The Gruppen Kommandeur, Hpt von Maltzahn, did the best he could by climbing and trying to hide in the clouds. Everybody succeeded but me, thanks to my excellent propeller. My aircraft could not climb like the others had and therefore all the RAF fighters turned on me and I had no chance of escaping by diving as that wonderful propeller would ensure that I would travel at just 300 to 350kmh. Therefore I decided to fly straight ahead trying to gain altitude a metre at at time, perhaps reaching cloud without being shot down. I saw the Spitfires flying around me and shooting and my plane was hit several times... He then hit my my fuel tank which caught fire immediately. Within a second, my cabin was full of smoke and fire and I had to get out. 120

Oberleutnant Jochen Schypek, 5/JG 54, reiterated Mölders' view of the Spitfires' negative 'g' problems:

We were attacked when the bombers had reached the London Docks and I yelled an alarm "Indians at six o'clock!" ...With them, we had developed a standard and often successful procedure - our Daimler Benz engines were fuel injection ones whilst the Spitfires had carburettor engines. This meant once we put our noses down vertically and quick enough, our engines would continue to function without interruption whilst the Spitfires - and Hurricanes - attempting to stick to our tails would slow down long enough for us to put a safer distance between them and ourselves. The slowing down was the consequence of the float in the carburettor getting stuck due the the sudden change in position.

I had managed to break away at least a dozen times by means of this manoeuvre but lo and behold, it did not work this time! The 'Indian' was right on my tail in my steep dive and opened fire. I could see bullets hitting my wings and, from the white trails on both sides, I knew he had hit my radiator... My 'Indian' drew alongside and the aircraft appeared strange to me as I had never been so close to a live Spitfire before. I was rather relieved that he recognised I did not have any chance of getting home and that he did not insist he complete his kill... 121

Oberleutnant Gerhard Schöpfel, Gruppenkommandeur of III./JG 26 wrote of the Me 109 E:

It was superior to the Hurricane and above 6,000 metres, faster than the Spitfire also. I believe that our armament was the better, it was located more centrally which made for more accurate shooting. On the other hand, the British fighters could turn tighter than we could. Also I felt that the Messerschmitt was not so strong as the British fighters and could not take so much punishment. 122

Oblt Hans Schmoller-Haldy of JG 54 commented:

    My first impression was that it had a beautiful engine. It purred. The engine of the Messerschmitt 109 was very loud. Also the Spitfire was easier to fly, and to land than the Me 109. The 109 was unforgiving of any inattention. I felt familiar with the Spitfire from the start. That was my first and lasting impression. But with my experience with the 109, I personally would not have traded it for a Spitfire. It gave the impression, though I did not fly the Spitfire long enough to prove it, that the 109 was the faster especially in the dive. Also I think the pilot's view was better from the 109. In the Spitfire one flew further back, a bit more over the wing.
    For fighter-versus-fighter combat, I thought the Spitfire was better armed than the Me 109. The cannon fitted to the 109 were not much use against enemy fighters, and the machine guns on top of the engine often suffered stoppages. The cannon were good if they hit; but their rate of fire was very low. The cannon had greater range than the machine guns. But we were always told that in a dogfight one could not hope to hit anything at ranges greater than 50 metres, it was necessary to close in to short range. 123

Günther Rall, who served with III./JG 52 during the Battle of Britain, reflected on the strengths and weaknesses of the adversaries at that time:

The elliptical wings of the Spitfires had fantastic characteristics, great lift. They were very maneuverable. We couldn't catch them in a steep climb. On the other hand they could stall during inverted maneuvers, cutting off the fuel because the force of gravity prevented the flow of fuel. But they were still a highly respected enemy. In contrast, our Bf 109s had shortcomings. I didn't like the slats and our cockpits were very narrow, with restricted rear visability. Fighter pilots need a good all-round field of vision and we didn't have it. 124

Adolf Galland wrote of the matchup: "the ME-109 was superior in the attack and not so suitable for purely defensive purposes as the Spitfire, which although a little slower, was much more manueuverable" and in a fit of frustration uttered the famous passage to Göring "I should like an outfit of Spitfires for my Squadron". 125

The conclusions of the RAF, beginning with the Royal Aircraft Establishment (RAE):

Longitudinally the aeroplane is too stable for a fighter. There is a large change of directional trim with speed. No rudder trimmer is fitted; lack of this is severely felt at high speeds, and limits a pilot's ability to turn left when diving.

Aileron snatching occurs as the slots open. All three controls are too heavy at high speeds. Aerobatics are difficult.

The Me 109 is inferior as a fighter to the Hurricane or Spitfire. Its manoeuvrability at high speeds is seriously curtailed by the heaviness of the controls, while its high wing loading causes it to stall readily under high normal accelerations and results in a poor turning circle. 126

The Aeroplane and Armament Establishment at Boscombe Down reached a similar conclusion:

In general flying qualities the aeroplane is inferior to both the Spitfire and the Hurricane at all speeds and in all conditions of flight. It is much inferior at speeds in excess of 250 m.p.h. and at 400 m.p.h. recovery from a dive is difficult because of the heaviness of the elevator. This heaviness of the elevator makes all manoeuvres in the looping plane above 250 m.p.h. difficult including steep climbing turns. No difference was experienced between climbing turns to the right and left. It does not possess the control which allows of good quality flying and this is particularly noticeable in acrobatics. 127

Jeffrey Quill, Chief Test Pilot for Supermarine, compared the Me 109E to the Spitfire I as follows:

My experience in fighting against the BF. 109 E in a Spitfire Mk. I was mostly around or above 20,000 feet and led me to the conclusion that the Spitfire was slightly superior both in speed and rate of climb, that is was a more 'slippery' or lower drag aeroplane, and that it was outstandingly better in turning circle. 128

In October 1940 I flew a captured Me 109E; to my surprise and relief I found the aileron control of the German fighter every bit as bad - if not worse - at high speed as that of the Spitfire I and II with fabric-covered ailerons. They were good at low and medium speed, but at 400 mph and above they were almost immovable. I thought the Me 109E performed well, particularly on the climb at altitude, and it had good stalling characteristics under g except that the leading-edge slats kept snapping in and out. But it had no rudder trimmer - which gave it a heavy footload at high speed - while the cockpit, the canopy and the rearward vision were much worse than in the Spitfire. Had I flown the Me 109 earlier I would have treated the aeroplane with less respect in combat. 129

F/L Robert Stanford Tuck, who had an opportunity to fly a captured Me 109 E3 in May 1940, had a rather more positive view of the 109 stating: "without a doubt a most delightful little airplane - not as maneuverable as the Spit mind you, nor as nice to handle near the ground", giving high marks to the 109's higher rudder pedals and agreeing with Mölders that the the 109 had an advantage in that "our Merlin engines couldn't stand up to negative 'G' whereas the Messerschmitt's Daimler-Benz seemed quite unaffected". 130

P/O H.R. "Dizzy" Allen (later Wing Commander) of No. 66 Squadron, echoing Tuck, wrote of the matchup with an eye on tactical doctrine:

We were better at dogfighting than the fighter arm of the Luftwaffe, but only because both the Spitfire and Hurricane were more manoeuvrable than the Messerschmitts 109 and 110. In fact, dog-fighting ability was not all that important during the war. Fighter attacks were hit-or-miss affairs on average. Either you dived with the sun behind you and caught him napping, or he did that to you. I occasionally had to mix it in dog-fights with German fighter pilots, and either I would shoot them down or they would shoot me down, or I would lose sight of them because their camouflage was better than mine. The reason we were more manoeuvrable than them was because the Me-109 had a higher wing loading than our fighters. This gave us advantages, but they also had certain benefits. We had no idea that the Daimler-Benz engines in the 109s were fuelled by direct-injection methods. Our carburettors were a definate handicap. The Germans could push down the nose of their fighters, scream into a vertical dive, as if beginning a bunt, and accelerate like made away from us. When we tried that tactic, our carburettors would flood under negative gee, and our engines would stall momentarily - as they frequently did - which lost us all-important seconds during the engagments. 131

Alan Wright of No. 92 Squadron wrote:

There seemed to be more dog-fighting over Dunkirk than later, in the Battle of Britain or when escorting bombers over France. By then one side or the other was only too well aware of the distance and fuel necessary to get back to base. Then it became a matter of ‘bounce’, from up-sun if possible, attack and climb up again and out of the way. The Germans, when attacked over the UK, and occasionally over Dunkirk, would usually open up the taps and dive for home. There was good reason for this. Other things being equal, the Spitfire had the edge in the climb over the 109, while the 109 had the edge in the dive flat out. The ME109 pilots also found out over Dunkirk that the Spitfire had the tighter turned circle, which meant that after a turn or two of a two-plane dogfight, the Spitfire would have the 109 in its sights. At Dunkirk we were discovering these things. 132

Alan Deere, who served with No. 54 Squadron during the Battle of Britain, summed it up:

Undoubtedly, the 109 in the hands of a good pilot was a tough nut to crack. Initially, it was faster in the dive, but slower in the climb; the Spitfire could out-turn, but it was at a disadvantage in manoeuvres that entailed negative G forces. Overall there was little to choose between the two fighters. 133

Hugh Dundas thought the antagonists to be evenly matched:

There is no doubt, that Goering and his commanders overrated the effectiveness of their fighters in relation to our own. In fact the Messerschmitt 109 and the Spitfire were extraordinarily evenly matched. Their duel for supremacy lasted throughout the war, as each plane was constantly improved and given increased power and performance. At times the Germans, by rushing out a new version before our own next improvement was ready, would get one jump ahead. At other times the advantage would be to the RAF. But on balance the Spitfire was, I believe, slightly the better aircraft. And so it was in 1940. In particular, such advantages as it enjoyed over the ME 109 at the time were enhanced by the circumstances of the battle. 134

616 Squadron Spitfire I lands at Coltishall, September 1940

The Spitfire I had reached maturity by the outset of the Battle of Britain and began to be replaced by the Spitfire II in August. This improved variant first entered service with No. 611 Squadron, 135   eventually equipping over a third of the Spitfire squadrons by the end of the Battle. Oberleutnant Ulrich Steinhilper of III/JG 52 flew a Me 109 E-1, armed with 4 MG 17 machine guns, until 15 September 1940, whereupon he received a cannon equipped Me 109 E-4. 136 A month later he wrote home:

The British have, in part, a new engine in their Spitfires and our Me can hardly keep up with it. We have also made improvements and have also some new engines, but there is no more talk of absolute superiority. The other day (12 October) we tangled with these newer Spitfires and had three losses against one success. I got into deep trouble myself and my Rottenhund (Sigi Voss) was shot down. I ended up against two Spitfires with all weapons jammed. There was no alternative but to get the hell out of it. 137

Steinhilper and his wingman were shot down by the Spitfire Mk IIs of No. 74 Squadron on 27 October 1940. During the last phase of the Battle a third of the Me 109s were transformed into fighter-bombers, much to the consternation of the fighter pilots that had to fly it. 138   Improved versions of the BF 109 E, with the trouble plagued DB.601N, 139   began to show up in insignificant, penny packet numbers towards the end of the Battle, presaging the advent of the very capable Me 109 F. Thus the stage was set for continuous, performance enhancing improvements to the respective types right through to VE day - and beyond in the case of the Spitfire.

Miscellaneous Particulars

Fuel Consumption:-

Spitfire IMe 109 E
Capacity85 gallons88 gallons
All-out level89 gal/hr at 17,000'5 minute Kurzleistung69 gal/hr at 14,763'
Climbing81 gal/hr at 12,000'30 minute erhöhte Dauerleistung66 gal/hr at 16,404'
Cruising Rich68 gal/hr at 14,500'Dauerleistung (Continuous)59 gal/hr at 16,076'
Cruising Weak49 gal/hr at 18,500'  
Most economical cruising25 gal/hr at 14,000'Sparsamer Dauerflug (Most economical)55 gal/hr

Dive speed limitations:-   from the Pilot's manuals: Spitfire I - 450 mph IAS., Me 109 E - 466 mph

Service ceiling:-  Spitfire I - 34,700 ft.,140  Me 109E - 33,792 ft.141

Source References

  1a.   Spitfire K.9787, Performance Trials, A.& A.E.E., 6th January 1939
  1b.   Spitfire K.9793, Short Performance with 2 pitch metal airscrew, A.& A.E.E., 12th July, 1939
  1c.   Spitfire L-1007, Handling and performance trials with two 20 m.m. cannon fitted, A.& A.E.E., 20th July, 1939
  1d.   Spitfire N.3171. Merlin III Rotol Constant Speed Airscrew. Comparitive Performance Trials., 19 March 1940
  1e.   Spitfire I X.4257 and R.6770, Brief Performance and Handling Trials
  1f.   RAE Chart of Spitfire I, Merlin III
           Russian chart Me 109 E3
  2a.   French Chart Me 109 No.1304
  2b.   French Figures Me 109 E
  2c.   French Figures Me 109 E Centre d'Essais du Material Aerien. No. 371, December 1939
  2d.   Swiss Chart Me 109/J-347
  2e.   Memorandum Report on Messerschmitt, Me 109 FS-M-19-1501-A. Army Air Forces Material Center.
  3.   Flugleistungkurven, BF 109 E Flugzeughandbuch, Berlin, 16 December 1939
  4.   Vollgashorizontalflüge, Meßprotokoll vom 26.4.38, B.F.W. Augsburg
  5.   Flugbegrenzungen (engine limitations) BF 109 E Flugzeughandbuch, Berlin, 16 December 1939
  6.   Meßprotokoll vom 6.4.39, Messerschmitt A.G., Augsburg
  7.   Meßprotokoll vom 16.2.39, Messerschmitt A.G., Augsburg
  8.   Comparitive Trials between a captured Messerschmitt 109 and British Fighters. Air Ministry S.5217., July 1940.
  9. F/O D. H. Watkins, Combat Report - 2 June 1940
10. P/O Peter St. John, Combat Report - 10 July 1940, Uffz Kull 5/JG 51, Me 109 E-4 forced-landed Calais, aircraft 30% damaged.
11. F/LT John Ellis, Combat Report - 24 July 1940,  Probably Uffz. Kroll, killed, 9/JG 51 Me 109 E-1.
12. S/L John Ellis, Combat Report - 12 August 1940
13. Sgt. H. Chandler, Combat Report - 14 August 1940, Probably: Oberfw Dabusga, 6/JG 3, Me 109 E-1.
14. F/Lt. L. G. Olive, Combat Report - 13 August 1940.
15. F/Lt. L. G. Olive, Combat Report - 24 August 1940.
16. P/O N. Agazarian, Combat Report - 26 September 1940.
17. F/Lt. Eric Thomas, Combat Report - 9 October 1940, Fw. Schweser 7/JG 54 captured, Me 109 E-4 Wk. Nr. 5327.
18.   19 Squadron Operations Record Book, November 1939, Delivery of Rotol Constant Speed propeller equipped Spitfire
19.   No 54 Squadron Operations Record Book. Form 540, December 1939.  Re-equipped with Rotol prop, Dec. ORB, pg 2
19b. Rotol Airscrews for Spitfire, Headquarters, Fighter Command, 16th June 1940
19c. 1 Squadron Operations Record Book, April 1940
19d. 1 Squadron Operations Record Book, May 1940
19e. 151 Squadron Operations Record Book, April 1940
19f. 151 Squadron Operations Record Book, May 1940
19g. Paul Richey DFC, Fighter Pilot (Redwood Press, Wiltshire 1990) p 93.
19h. W/C Ian Gleed D.F.C., Arise to Conquer, (Random House, New York 1942) pp. 62-63.
19i. The Latest Rotol Airscrew, Flight, May 23, 1940
19j. Conversion of Hurricane Aircraft D.H. Two-Pitch Airscrews to Constant Speed, Ministry of Aircraft Production, 29th June 1940
20.   611 Operations Record Book, June 1940
20b. 609 Operations Record Book, June 1940
20c. 74 Operations Record Book, June 1940
20d. 92 Operations Record Book, June 1940
20e. 65 Squadron Intelligence Patrol Report, 7 July 1940
20f. Spitfire Conversion of 2 Pitch De Havilland Airscrews to Constant Speed, Headquarters, Fighter Command, 17th June, 1940
20g. De Havilland Constant Speed Airscrews, Loose Minute Sheet, 22.6.40
20h. Spitfire I fitted with De Havilland Constant Speed Airscrew, 22.6.40
20i. Spitfire I Airscrews, Ministry of Aircraft Production, 1st July 1940
20j. "Spitfire" Conversion of Two Pitch De Havilland Airscrews to Constant Speed, Ministry of Aircraft Production, 11th July 1940
20k. Pitch Panic, Flight, December 9th, 1943
20l. Spitfire I Aeroplane, Merlin II Engine, AP 1565A
21. E. Morgan & E. Shacklady, Spitfire the History, (Key Publishing Ltd., Stamford, Lincolnshire, 1987), pp. 53-54.
22. Alec Harvey-Bailey, The Merlin in Perspective, (Rolls-Royce Heritage Trust, Derby, 1983), p. 155.
23. Betriebs und wartungsvorschrift zum Mercedes Benz Flugmotor, DB 601 A u. B., Ausgabe C, October 1940
23b. D.(Luft)T.3601 A u. B., DB 601 A u. B Motoren-Handbuch, Mai 1942, p. 18
23c. Betriebs und wartungsvorschrift zum Mercedes Benz Flugmotor, DB 601 A u. B., Ausgabe C, October 1940, p.17.
23d. Betriebs und wartungsvorschrift zum Mercedes Benz Flugmotor, DB 601 A u. B., Ausgabe C, October 1940, p.47
23e. Flight - November 7 1940. An Inverted Vee Engine, The Mercedes-Benz DB601A: Hydraulic drive to Supercharger: Clockwork Boost Control, Roller Bearing Big Ends
24. Rolls Royce Merlin engines- Max power level flight
25. D.(Luft)T.3601 A u. B., DB 601 A u. B Motoren-Handbuch, Mai 1942, Abb.3 Leistungsschaubild
26. Air Ministry Correspondence R.D.3.6. 14/11/39.
27. Merlin II and III - Use of +12 lb./sq.in. Boost Pressure - Alterations and Precautions, (March 20, 1940)
28a. No. 611 Operations Record Book, (21 March 1940)
28b. No. 74 Operations Record Book, (16 March 1940)
28c. No. 602 Operations Record Book, (16 February 1940)
28d. No. 151 Squadron Operations Record Book, (16 February 1940)
28e. No. 111 Squadron Operations Record Book,( 15 February 1940)
28f. No. 504 Operations Record Book, (24 February 1940)
28g. No. 605 Operations Record Book, (28 May 1940)
28h. David Ross, The Greatest Squadron of Them All, The Definitive History of 603 Squadron, RAauxAF, (Grub Street, London, 2003), p. 125.
28i. Alec Harvey-Bailey, The Merlin in Perspective, (Rolls-Royce Heritage Trust, Derby, 1983), p. 85.
28j. Alfred Price, The Spitfire Story, (Arms and Armour Press Ltd., London, 1986), p. 74.
28k. Hundred Octane, Flight, No. 1631 Vol. XXXVII, The Outlook, March 28, 1940.
28l. H. F. King, Fighter Station, With the Spitfires in Scotland, (Flight, No. 1631 Vol. XXXVII, March 28, 1940), pp. 290-295.
28m. "Aero", Correspondance, (Flight, January 6th 1944), p. 22.
28n. Air Commodore F. R. Banks, I Kept No Diary , Airlife Publications, Shrewsburg, 1978, Appendix II Fuel pp 234-236
28o. W.G. Dudek and D. R. Winans, excerpt from AIAA Paper No. 69-779, Milestones in Aviation Fuels, (Esso Research and Engineering Company, New York 1969.) p. 319.
28p. A. R. Ogston, excerpt from History of Aircraft Lubricants (Society of Automotive Enginees, Inc. Warrendale, PA USA), p. 12.
28q. Royal Air Force History - Spitfire,   Old Royal Air Force History Web page
28r. The Daily Inspection of a Spitfire, Training film by the Royal Airforce - various stills. Spitfire I in pre Battle of Britain camoflage with 609 Squadron Codes marked for 100 octane fuel.
28s. 602 Squadron Spitfire I in pre Battle of Britain camoflage marked for 100 octane fuel.
28t. Leo McKinstry, Hurricane, Victor of the Battle of Britain, (John Murrey Publishers, London, 2010), p. 87.
28u. Ibid., p. 191.
28v. Dilip Sarkar, How the Spitfire Won the Battle of Britain, (Amberley Publishing, Stroud, Gloucestershire, 2010), pp. 66-68.
28w. Robert Schlaifer, Development of Aircraft Engines, (Harvard University, Boston, 1950), pp.220-223
28x. The Trimpell Oil Refinery, Heysham Heritage Association
28y. Fuels and Lubricants Handbook: Technology, Properties, Performance, and Testing, (ASTM International, 2003). P. 89
28z. Andy Saunders, Spitfire Mark I P9374, (Grub Street, London, 2012), p. 98
28aa. 1912 to 1940, (Flight, No. 1634, Vol. XXXVII, April 18, 1940), p. 354
28bb. Dik A. Daso, Doolittle: Aerospace Visionary (Potomac Books, Washington D.C, 2003), p. 38.
28cc. Peter Pugh, The Magic of a Name, The Rolls-Royce Story, The First 40 years, (Icon Books, London, 2000), pp. 189-190; 229-230.
28dd. Bill Gunston, Rolls-Royce Aero Engines, (Patrick Stephens Limited, 1989). p. 72.
28ee. Tim Palucka , The Wizard of Octane, (Invention & Technology Volume 20, Issue 3, Winter 2005)
28ff. Gavin Bailey, The Arsenal of Democracy: Aircraft Supply and the Evolution of the Anglo-American Alliance, 1938-1942, (Edinburgh University Press, 2013), p. 104.
28gg. Dr. Alfred Price, Spitfire Mark I/II Aces 1939-41, (Osprey Publishing, 1996), p. 19.
28hh. Richard P. Hallion, "The American Perspective", in Paul Addison and Jeremy A. Crang (eds), The Burning Blue. A New History of the Battle of Britain (Pimlico, London 2000), p. 84.
28ii. Sir Stanley Hooker, Not Much of an Engineer, (Airlife Publishing, Ramsburg, Marlborough, Wiltshire, 2002), p50.
28jj. Wing Commander George Kerr, Time's Forlock (The Shell Petroleum Company Limited, London, 1948). pp. 36-38.
29. Al Deere, Combat Report - 26 May 1940 (Deere also noted use of +12 boost in Combat Report of 12 August 1940.)
30. F/Lt Brian Lane, Combat Report - 26 May 1940
31. P/O John Bushell. Combat Report, 18 May 1940
32. Assistant Cheif of the Air Staff, 100 octane approval for Spitfire Squadrons, 24th September 1938
32b. Headquarters Fighter Command, 100 'Octane' Fuel, 6th December, 1938.
32c. 100 Octane Fuel, Issue of, 12th December 1939
        See also 100 Octane Fuel - Issue of, 7 December 1939 & 100 Octane Fuel - Issue of, 9 December 1939
33. Gavin Bailey, The Narrow Margin of Criticality: The Question of the Supply of 100-Octane Fuel in the Battle of Britain, (English Historical Review Vol. CXXIII No. 501, Oxford University Press, 2008), p 406.
34. 5th meeting of the the Co-ordination of Oil Policy Committee, 2 April 1940, TNA, PRO, AVIA 10/282.
35. 7th meeting of the Co-ordination of Oil Policy Committee, 18 May 1940, TNA, PRO, AVIA 10/282
36. 9th meeting of the Co-ordination of Oil Policy Committee, 7 Aug 1940, TNA, PRO, AVIA 10/282
37. R. Hough & D. Richards, The Battle of Britain (Hodder & Stoughton, London, 1989), p. 387.
38. D. Wood & D. Dempester, The Narrow Margin, (Paperback Library, New York, 1969), p. 87.
39. 9th meeting of the Co-ordination of Oil Policy Committee, Revision of 100 Octane Fuel Statement
40a. Stocks - War Cabinet Oil Position, 13th May, 1941  
40b. 11th meeting of the Co-ordination of Oil Policy Committee, TNA, PRO, AVIA 10/282
40c. Table III - Stocks and Total Receipts and Expenditure, War Cabinet Oil Position 12th March, 1942 (NA)  
40d. Aviation Fuel and Oil, Total Weekly Issues, Air Ministry
40e. Table II - Expenditure, War Cabinet Oil Position 12th March, 1942 (NA)  
40f. Table II - Consumption, War Cabinet Oil Position 15th September, 1941 (NA)  
40g. V. A. Kalichevsky, The Amazing Petroleum Industry, (Rheinhold Publishing Corporation, New York, 1943), pp.7-8.
41. Pilot's Notes. Spitfire I Aircraft. AP 1565. Engine limitations
41b. Pilot's Notes. Spitfire I Aircraft. AP 1565A, 100 octane fuel
41c. Pilot's Notes. Spitfire I Aircraft. AP 1565A, Boost cut-out EMERGENCY Control
42. Handling of Merlin in Hurricane, Spitfire and Defiant Aircraft, H.C.T. Dowding, C-in-C Fighter Command, 1 August 1940.
42b. P/O T.D. Smith, Combat Report - 29 May 1940  
42c. Defiant K-8620, Level Speed and RPM at Heights - A.&A.E.E.
42d. A.P.1565A, Spitfire I Pilots Notes - Port cockpit view
42e. AP 1590B Merlin II and III Aero-Engines - Fig.45 Sectional Perspective Views of Automatic Boost Control
42f. Fig. 25. Engine Controls. A.P. 1565 A, The Spitfire I Aeroplane, 1st Edition June 1938, reprinted April 1940.
42g. Merlin II and III - Use of +12 lb./sq.in. Boost Pressure - Alterations and Precautions, (March 20, 1940)
42h. DRG.No. A.P.1590B/J.2/40 - Cut-out Valve for Boost Control
43. P/O John Freeborn, Combat Report - 24 May 1940
44. Colin Gray, Spitfire Patrol, (Hutchinson, London, 1990), p. 27.
44b. Dr Alfred Price. Spitfire I/II Aces 1939-41, Osprey Publishing, London, 1996), pp.11-12.
45. Gray, op. cit., p. 60.
46. Brian Lane, Spitfire!, (John Murray, 1942) reprinted in D. Sarkar, Spitfire Squadron, (Air Research Pub., New Malden, 1990), pp. 27-28.
46b. F/Lt Brian Lane, Combat Report - 26 May 1940
47. F/Sgt. G. C. Unwin, Combat Report - 1 June 1940
48. P/O M. P. Brown, Combat Report - 2 June 1940
49. F/LT John Ellis, Combat Report - 12 June 1940
50. F/LT. John Webster, Combat Report - 19 June 1940
50b. P/O J. P/ Studd, Combat Report - 9 July 1940
50c. Sgt. A. Smith, Combat Report - 9 July 1940
51. F/Lt D. P. Kelly, Combat Report - 28 July 1940
52. F/LT. John Webster, Combat Report - 28 July 1940,  Major Werner Mölders wounded, Stab JG 51, Me 109 E-3 a write off.  I/JG 51 Me 109 E-1, 20% damage.
53. F/LT. John Webster, Combat Report - 29 July 1940
54. P/O George Bennions, Combat Report - 28 July 1940,  Gefr. Gebhart missing, 2/JG 1, Me 109 E-1.
55. Arthur G. Donahue, Tally-Ho! (The MacMillan Company, New York, 1941), p. 35.
56. F/LT. John Webster, Combat Report - 8 August 1940
57. F/O R.W. Wallens/Green Section, Combat Report - 11 August 1940
58. 41 Squadron composite Combat Report 15 August 1940
59. F/Lt George Gribble, Combat Report - 15 August 1940
60. Hugh Dundas, Flying Start, A Fighter Pilot's War Years (St. Martins Press, New York, 1989), p. 38.
61. F/Lt Robert Boyd, Combat Report - 18 August 1940,  Uffz. Nolte killed, 6/JG 27, Me 109 E-4.
62. David Ross, The Greatest Squadron of Them All, The Definitive History of 603 Squadron, RAauxAF, (Grub Street, London, 2003), p. 194.
63. P/O Ronald Berry, Combat Report - 31 August 1940,  Oberleutnant Helmut Rau I/JG3 captured, Me 109 E-4 Wk Nr 1082.
64. Sgt. Jack Stokoe, Combat Report - 1 September 1940,  Oblt Bauer killed III/JG 53, Me 109 E-4 4020.
65. Roger Hall D.F.C. Clouds of Fear, (Hodder and Stoughton, London, 1977), pp. 85-86.
66. Robert Oxspring, Spitfire Command, (Grafton Books, London, 1987), pp. 59-60.
67. P/O R.D. Elliott, Combat Report - 9 September 1940,  Probably one of the 3 Me 110 C that 9/ZG 76 lost.
67b.P/O H. R. Allen, Combat Report - 9 September 1940
68. F/O Brian Macnamara, Combat Report - 27 September 1940
69. Wing Commander Bob Doe, Fighter Pilot, (CCB Associates, Selsdon, Surrey, 1999), p. 29.
70. Geoffrey Wellum, First Light, (John Wiley & Sons, Hoboken, New Jersey, 2002), p. 147.
71. F/Lt. D. M. Crook D.F.C., Spitfire Pilot, (Faber and Faber, London, 1942), pp. 80-82.
      Crook's victims probably were Gefreiter Fritz Schumacher, Me 109 E-4 Nr. 3447 5/JG 2 & Me 109 E-1 Nr. 2693 5/JG 53.
72. F/O D.A.P. McMullen, Combat Report - 15-10-40
72b. P/O/ G Bodie, Combat Report - 25 October 1940
73. Morgan & Morris, Messerschmitt Me. 109, Handling and Manoeuvrability Tests, Report No. B.A.1640 (Royal Aircraft Establishment, Farnborough, September, 1940), p. 2.
74. J.A.D. Ackroyd and P. J. Lamont, “Comparison of turning radii for four Battle of Britain fighter aircraft”, Aeronaut J, 104, (1032), pp. 53-58, 2000.
75. J. Quill, Spitfire - A Test Pilot's Story, (Crecy, Manchester, 1998), pp. 185-187.
75. Ibid., p. 185
76. Quoted in R. Smith, Al Deere - Wartime Fighter Pilot Peacetime Commander (Grub Street, London, 2003), p. 43.
77. F/Sgt William H. Franklin, Combat Report - 24 June 1940.
78. F/LT John Ellis, Combat Report - 24 July 1940
79. Donahue, op. cit., p. 57.
80. P/O D. Hastings, Combat Report - 11 August 1940,  JG 2 lost 7 Me 109s in combat with 74 Squadron.
81. F/O William Nelson, Combat Report - 11 August 1940.,  JG 2 lost 7 Me 109s in combat with 74 Squadron.
82. F/Sgt William H. Franklin, Combat Report - 16 August 1940.
83. S/P A. McDowall, Combat Report - 18 August 1940,  Oblt. Trumpelmann killed, 1/JG 27, Me 109 E-1.
84. Sgt N. Ramsay, Combat Report - 26 August 1940, Fw Ziegler POW, 3/JG 52 Me 109 E-1.
85. P/O Ronald Berry, Combat Report - 28 August 1940.P/O Ronald Berry, Combat Report - 28 August 1940.,  probably 5/JG3 which lost 1 Me 109 E-1 & 2 Me 109 E-4 into sea in combat with 603 Sqdn. All three pilots rescued.
86. Sgt R. Hamlyn, Combat Report - 30 August 1940
87. Sgt B. Douthwaite, Combat Report - 2 September 1940.
88. Lane/Sarkar, op. cit., p. 67-68.
89. George Unwin, Imperial War Museum, No. 11544
90. J.W. Villa, Combat Report - 9 September 1940.
91. Wellum, op. cit., pp. 152-154, 165.
92. P/O George Bennions, Combat Report - 5 September 1940,   Oblt. von Werra POW, Stab II/JG 3, Me 109 E-4 1480. Finished off by P/O Stapleton 603 Sqdn.
93. P/O George Bennions, Combat Report - 15 September 1940
94. Comparitive Trials between a captured Messerschmitt 109 and British Fighters. Air Ministry S.5217., July 1940.
95. Sgt. Jack Stokoe, Combat Report - 31 August 1940,  Lt. Walter Binder killed, 3/JG 3, Me 109 E-4 1503.
96. P/O J. G. Drummond, Combat Report - 24 September 1940
97. P/O D. C. Winters, Combat Report - 1-9-40.
98. Sgt P. Else, Combat Report - 25 July 1940, III/JG 2, Me 109 E-1 crashed in sea, wounded pilot rescued by Seenotdienst.
99. Gray, op. cit., p. 35.
100. Dundas, op. cit. p. 34.
101. Donald Caldwell, The JG 26 War Diary, Volume One, (Grub Street, London, 1996), p. 72.
102. Heinz Knoke, I flew for the Führer, (Berkely, New York, 1959), pg. 32.
103. Quoted in Jochen Prien & Gerhard Stemmer, Jagdgeschwader 3 "Udet" in World War II, Vol 1., (Schiffer Publishing Ltd., Atglen, PA, 2002), p. 75.
104. Morgan, op. cit., p. 28.
105. L.Dv.556/3, BF 109 E Flugzeughandbuch, (Berlin, December 1939), p. 19.
106. Morgan, op. cit., p. 24.
107. Ibid., p. 27.
108. F/Sgt. Tew, Combat Report - 18/8/40.
109. Morgan, op. cit., p. 25.
110. Pilot's Notes. Spitfire I Aircraft. AP 1565., 13.(i)
111. Quoted in S. Bungay, The Most Dangerous Enemy, A History of the Battle of Britain, (Arum Press, London, 2000), p. 161.
112. Douglas McRoberts, Lions Rampant, The Story of 602 Spitfire Squadron, (William Kimber, London, 1986) p. 94.
113. S/Ldr. James Leathart, Combat Report - 2 September 1940
114. Quoted in A. Price Spitfire at War (Ian Allen, 1985), p. 14.
115. No. 19 Squadron Operations Book, 1 November 1939
116. Morgan & Shacklady, Spitfire The History (Key Publishing Ltd, Lincolnshire, 1987), p. 53.
116b. No. 611 Operations Record Book, 28 June 1940
116c. No. 609 Operations Record Book, 26 June 1940
116d. No. 74 Operations Record Book, 28 June 1940
116e. No. 92 Operations Record Book, 25 June 1940
116f. 65 Squadron Intelligence Patrol Report, 7 July 1940
117. No. 609 Operations Record Book Reference to rear armour plating, 27 May 1940.
117b. No. 611 Operations Record Book Reference to pilot's armour plating, 2 June 1940.
117c. No. 41 Operations Record Book Reference to rear armour plating, 23 November 1939.
117c. No. 152 Operations Record Book Reference to rear armour plating, 24 May 1940.
118. Adolf Galland, The First and The Last, (Buccaneer Books, Cutchogue, New York, 1954), p. 29.
119. Ulrich Steinhilper & Peter Osbourne, Spitfire on my Tail, (Independent Books, Bromley, 1990), p.303.
120. Chris Goss, The Luftwaffe Fighters' Battle of Britain, (Crecy, Manchester, 2000), p. 155. Lt Erich Bodendiek POW, Stab II/JG 53, Me 109 E-1 Wk Nr 4842, s.d. P/O Oxsbring 66 Sqdn.
121. Goss op. cit. pp. 184-185. Oblt. Jochen Schypek 5/JG 52, POW, Me 109 E-4 Wk Nr 1988, shot down by F/O Brown 41 Sqdn.
122. Alfred Price, The Hardest Day, (Charles Scribner's Sons, New York, 1980), p. 6.
123. Price, op. cit., pp. 16-17.
124. Jill Amadio, Günther Rall: a memoir, (Tangmere Productions, Santa Ana, CA), pp. 53-54.
125. Galland, op. cit. pp. 28-29.
126. Morgan & Morris, op. cit., pp. 1-2.
127. Report No.A.&A.E.E./755., Messerschmidt 109 Fighter, Brief Handling Trials (Aeroplane and Armament Establishment, Boscombe Down, 10 June 1940), p. 1.
128. J. Quill, Birth of a Legend - The Spitfire, (Quiller Press Ltd, London, 1986), p. 140.
129. Quill, op. cit., p. 200.
130. Larry Forrester, Fly for Your Life, (Bantom Books, New York, 1981), p. 123.
131. Wing Commander Dizzy Allen, DFC, Fighter Squadron, (Granada, London, 1982), pp. 57-58.
132. Norman Franks, Air Battle for Dunkirk, (Grub Street, London, 2006),p. 167.
133. Smith, op. cit., p. 30.
134. Dundas, op. cit., pp. 34-35.
135. No 611 ORB, August 1940
136. Steinhilper, op. cit., p.280,282, 295-297.
137. Ibid., p.323.
138. Galland, op. cit. p. 42.
139. Kesselring as cited in A. van Ishoven, Messerschmitt Bf 109 at War, (Ian Allan, Shepperton, 1977), p. 107. leaking valves, supercharger faults/failure.
      Olivier Lefebvre, noted authority on the Me 109, commented : "Only a few E-4 received the DB601N (as E-4/N), the engine was very troublesome and was not fitted to many emil. Moreover it needed 100 oktan fuel which was not very common at that time." Also of interest are his comments on the DB 601A used: "E-1, E-3 and E-4 used the same engine: DB601A-1, the DB601Aa was an export variant of the DB601A not used on Luftwaffe Emils. The DB601Aa is only mentionned in field manual for foreign airforces be it Swiss or Yugoslav manuals for instance. The foreign licence production for Aichi or Kawasaki cover only the DB601Aa/Ba not the DB601A-1. Moreover the DB601Aa manual is really not to Luftwaffe standard and read more like a propaganda liflet or advertissement rather than a technical manual... And the power output are calculated in a different way that Luft manuals, and i highly suspect that the outpout were given a boost in the manual...There is no Luft version of this manual, and the standard DB601A-1 manual was updated in 1942. Moreover no German aircraft captured were equipped with DB601Aa."
140. A.& A.E.E Ref: 4493/44
141. L.Dv.556/3, op. cit., Blatt 2.

      Report on Investigation of Turning Circles of M.E. 109, Spitfire and Hurricane
      R.A.E. Technical Note No. Aero 1106
      Notes on the Dog Fight, S.B. Gates, Reports and Memoranda No. 2381, June 1940.

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