The twin-engine Bristol Blenheim entered RAF service in 1937, replacing obsolete aircraft such as the Hawker Hind biplane. But the Blenheim itself quickly became obsolete, having only one moveable gun and being unable to outpace the fast enemy fighters. Blenheim crews carried out many daring daylight attacks on shipping and land targets but suffered very heavy losses.
The single-engine Fairey Battle was an obsolete aircraft even before it flew its first operational mission for the RAF. Slow, with just one defensive gun, Battles were easy prey for fast German single-seat fighters like the Messerschmitt 109. However RAF Bomber Command crews fought courageously to try to halt the German advance through the Low Countries of Holland, Belgium and Luxembourg, winning two Victoria Crosses but suffering heavy casualties.
The American built Boston was a useful twin-engine light bomber which replaced the Blenheim and was itself eventually replaced by the Mosquito.
The Lockheed Ventura was not a successful aircraft for Bomber Command. The American built twin-engine light bomber was outdated by the time it joined the RAF in 1942 at a time when the hugely successful Mosquito was becoming operational.
The De Havilland Mosquito was a completely radical design idea: A light-weight wooden bomber with no defensive guns, relying on outright speed from its two Rolls-Royce Merlin engines to escape enemy fighters. The result was the highly successful ‘Wooden Wonder’. With just a two-man crew it was able to carry a 4,000 lb bomb to Berlin – yet because of its wooden construction it could be partially assembled by carpenters and joiners and not use valuable factory space and metal supplies needed for conventional aircraft production.
The single-engine Lysander was designed for army co-operation and was also used for air-sea rescue, target tugs and liaison duties. It could manage a remarkably short take-off and landing run of 150 yards. This made it perfect for hazardous top-secret operations by Bomber Command to drop off and pickup agents in enemy-occupied Europe. The Lysander pilots would fly at night to pre-arranged points, normally in northern France, look for faint torch signals, then land in unfamiliar, unlit fields for a few seconds, hoping the shadowy figures that approached were Resistance fighters and not German soldiers. Within moments the pilot would take off again, never knowing the identity of the passengers.
The twin-engine Whitley entered RAF service in 1936 and was the RAF’s first ‘heavy bomber’. It was capable of carrying up to 7,000 lbs of bombs and had a range of up to 1650 miles. However it was slow and notoriously cold and uncomfortable for its crews and became known as the ‘Flying Coffin’.
The Hampden was an early design that first flew in 1936. Twin-engined and with a crew of four, it was popular with pilots because it handled well, but like other bombers of its time was vulnerable to enemy fighters and transferred from daylight to night operations. The Hampden was particularly suited for the valuable role of mine-laying at sea and many enemy ships were sunk as a result.
The Wellington was popular with its five man crews particularly because of it’s ability to absorb considerable damage and continue flying, thanks to an unusual ‘honey-comb’ metal construction which was immensely strong but light-weight. A largely successful twin-engine bomber it flew early daylight raids at the beginning of the war but proved easy prey for German fighters. The RAF learnt the hard way that no bomber could defend itself in daylight against modern fighters and the Wellington was transferred to night bombing.
The North American Mitchell was flown operationally by the RAF from January 1943. Manufactured in the USA, it had two engines and a crew of five. Known as the B-25 by the USAAF, the Mitchell was a useful bomber for the RAF. Mitchells flew extensive daylight missions in support of Allied troops around D-Day (June 1944).
The Stirling, designed prior to the Lancaster and Halifax, was an enormous aircraft, with four engines and a crew of seven. Throughout its service its design limitations (chiefly its wings being too short for the large size of the aircraft) resulted in poor performance and a high loss rate.
The twin-engine Manchester was not a successful aircraft, being under-powered by two very unreliable engines. But in re-developed form with the addition of two further improved engines and a longer wingspan it evolved into the famous Lancaster bomber.
The Avro Lancaster became the most effective heavy bomber of WW2 and formed the back-bone of the Bomber Offensive against German industrial cities. It was well-liked by pilots, having four powerful and reliable Rolls-Royce Merlin engines (the same as fitted to the Spitfire fighter) and excellent handling characteristics. It had a crew of seven (Pilot, Navigator, Flight Engineer, Wireless Operator, Bomb Aimer/Front Gunner, Mid-Upper Gunner and Rear Gunner). Specially adapted Lancasters took part in the famous ‘Dambusters’ raid. Lancasters also dropped five ton ‘Tallboy’ bombs to sink the much-feared German battleship ‘Tirpitz’ and by the end of the war were able to drop the 10 ton ‘Grand Slam’ bomb on precision targets such as bridges and viaducts.
The four-engine Halifax was an important bomber which played a major role in the Bomber Offensive, though it was never as successful as the Lancaster. The Halifax was repeatedly updated to try and improve handling problems and poor engine performance which made it more vulnerable to flak and fighters and thus caused an increased loss rate. Later versions were much improved.
The Boeing B-17 Fortress (The ‘Flying Fortress’) was supplied in limited numbers to the RAF early in the war and used for electronic counter-measures. It later played a major role in the success of the USAAF’s daylight bombing operations.
The Consolidated Vultee Liberator was an American four-engined heavy bomber (known by the USAAF as the B-24) first supplied in small numbers to the RAF in 1940/41 and soon found to be unsuitable for bombing operations in Europe. Subsequently used mainly by RAF Coastal Command for long-range reconnaissance missions and as a transport aircraft (a Liberator was used by Winston Churchill as his personal transport).