BATTLE OF BRITAIN ~ THE GERMAN ADVERSARY
In the interests of completeness, after my posts on the Spitfire and Hurricane, some information on Germany’s most important fighter of WWII, the Me / Bf 109. The 109 first flew in May 1935, saw service in the Spanish Civil War, fought with the Luftwaffe all through WWII, and was still in service with the Spanish Air Force up until the end of 1965. The 3 top scoring German aces of the war all flew the 109. Designed by Willy Messerschmitt and Robert Lusser the Bf 109 was the smallest and lightest airframe that could accommodate the largest engines under development in Germany, a pilot, and as it turned out not enough armament.
Lacking the grace of the Spitfire, or the rugged charm of the Hurricane, the Bf 109 looked like the killing machine it was. Straight line simplicity is about the best one could say about its shape. Or that it looks like a deformed glider, which is exactly what the Bf 109 was. It’s chief designer, Willy Messerschmitt, cut his aeronautical teeth designing gliders. His PhD thesis was accepted even though it was the plans for a glider.
In 1935 the Bf 109 did have all the elements for a cutting edge fighter; a low wing monoplane of flush-riveted stressed skin construction, retractable undercarriage, enclosed cockpit and ‘heavy’ armament. The Hawker Hurricane was not as up to date as the 109. The Hurricane was also much larger, slower, and mostly heavier. Even the Spitfire was a bigger aircraft than the Bf 109 ~ the 109 had a wing area of just about 70% of a Spitfire’s.
A quick look at a Spitfire in comparison with a Bf 109 shows that the RAF pilot had a sliding bubble canopy, which gave an excellent all-round view. Until the introduction of the slightly better ‘Galland Hood‘ the Luftwaffe pilot had a heavy framed cockpit canopy to contend with. Contemporary accounts from RAF pilots who sat in an 109, describe the pilots view as terrible.
Because there was a lot of glider in the fighter’s genetics, the 109’s small wings were beautifully thin, using leading edge slots and slotted trailing edge flats to increase the wing area. The wing was not stressed by the landing gear, as its loads were taken by the fuselage. This resulted in one of the 109’s operational weaknesses ~ a very narrow-track undercarriage. There were a large number of ground accidents during the 109’s operational career, the 109 was proving to be a fatally unforgiving aircraft
The thin, clean, wings would result in another operational weakness in the 109’s later life. Unlike the wings on most fighters of the time, the wings on a 109 were not designed to carry armament. The initial specification issued by the German Air Ministry had called for an armament of only 2 rifle caliber MG17 machine guns, mounted in the fuselage. When the news that both the Spitfire and Hurricane were 8 gun fighters, a third MG17 firing through the propeller hub was added to the Bf 109’s war load. The difficulty of installing heavier armament would result in later marques of the 109 sprouting lumps and bumps all over the wings and forward fuselage.
The very first 109 was powered by a Rolls-Royce Kestrel. Production models mostly used the Daimler-Benz DB605, an inverted V12 of 35.7 litres (2179 cu in), generating anything from 1,000 bhp to almost 2,000 bhp. Although the power output was remarkably similar to that of the 27 litre Rolls-Royce Merlin used in the Spitfire, there were two key differences. The 109 had fuel injection against the Spitfire’s carburetor, which meant the 109 could pull negative G and the Spitfire couldn’t. The smaller Merlin had better fuel consumption than the 35.7 litre DB605, which gave the Spitfire slightly longer operational endurance. There was a third difference, the DB605 caught fire a lot more often than the better-built Merlin.
The Luftwaffe found it extremely difficult to augment the 109’s limited internal fuel capacity with external drop tanks. Over England a mission lasting an hour was long. A mission lasting an hour and a half was to have an in-flight emergency. Many pilots were saved by the excellent glide characteristics built into the 109 by Messerschmitt, the erstwhile glider designer.
These then were the adversaries during the Battle of Britain. The Hawker Hurricane was outclassed by the Bf 109, which in itself was the equal of the Spitfire in the air.
The first contests between the fighters of the Luftwaffe and the RAF took place during the Battle of France. This was bad news for the RAF as its best fighter squadrons deployed to France were equipped with the Hurricane, a machine outclassed by the Bf 109. At least the Hurricane pilots had more chance than RAF pilots flying the obsolete Fairy Battle. (To be fair, the Fairy Battle was a fairly new design, it was obsolete while it was still on the drawing-board.) Resisting the call to send more and more Hurricanes to France, the battle was lost and the RAF prepared for the coming air assault on England.
The Bf 109’s greatest asset was its speed, but that came at a price. The small 109 was all engine, pilot, and fuel. The narrow track undercarriage was extremely dangerous on a grass airstrip, many young Luftwaffe pilots never got the chance of a second flight in a 109, and during the Battle of Britain the Luftwaffe was often operating from grass airstrips.
One oft-forgotten disadvantage the Bf 109 suffered throughout its life was the petrol, (gasoline), it had to use. From early in the war RAF fighters used the 100 octane petrol first used by the 1931 Schneider Cup seaplane racers. This provided the Spitfire with an extra 34 mph in Emergency Boost. The 109, like the rest of the Luftwaffe, had to make do with 87 octane fuel throughout its life.
The Bf 109 fought in throughout WWII, its nadir coming with the advent of the North AmericanP-51 Mustang in the skies over Germany. This remarkable aircraft gained air superiority ~ having a performance the Bf 109 just could not match.
After the war the Bf 109 soldiered on as the Hispano Aviacion HA-1112, initially with Hispano engines and later with the Rolls-Royce Merlin. This variant was officially the HA-112-M1L, but is invariably known as the Bouchon. (These are the 109s seen in the 1969 film Battle of Britain.) The aircraft was retired from active service on 27 December 1965.