de Havilland Mosquito - World War II Aircraft
Created | Updated Jan 12, 2007
Gloster Gladiator | de Havilland Mosquito | Boulton Paul Defiant
Bristol Beaufighter | Westland Whirlwind
Supermarine Spitfire | Hawker Hurricane
The Mosquito - or the DH-98 de Havilland Mosquito, to give its full name - almost wasn't. It was first proposed to the British Air Ministry in 1938 by designer Geoffrey de Havilland himself, who was obviously worried about the situation in Europe. The idea was that he would manufacture such a fast-moving aircraft that it could fly unarmed and simply outrun any enemy plane. But the Air Ministry was not happy with this suggestion and turned the request down.
The Drawing Board
Realising the possibilities of such an aircraft, however, de Havilland kept at it as a private venture. He planned an incredibly light airframe by removing all weapons and, instead of a six-man crew, reducing that to just two, a pilot and navigator sitting side-by-side. He also brought innovative construction techniques to the party - another sticking point with the Air Ministry - in that the plane was to be predominantly wooden. This was genius, as most metal was in short supply and metal workers already overstretched. However, there was a whole bunch of woodworkers who were not of much use: everything from 'proper' carpenters and joiners through to the specialists, such as piano makers and furniture makers1.
The Mosquito fuselage was a plywood-balsa-plywood laminate built round spruce stringers2. It was built in two halves, moulded on some concrete formers and, once all the wiring and control systems put in place, glued together. The wings were basically plywood skins over a couple of spars. The control surfaces were an alloy, light and strong, covered with a metal skin on the ailerons and a simple fabric on the tail.
Even with a body twice the weight and wetted area3 of the Spitfire, de Havilland concluded that the Mosquito's two Rolls Royce 'Merlin' engines would still power it to a speed at least 20mph faster than the Spitfire. The Air Ministry was not convinced, but even so they ordered 50 of the twin-engined two-seat monoplane from de Havilland on 1 March, 1940, sight unseen. This order was cancelled due to the evacuation from Dunkirk, but after several more attempts they finally confirmed the order when the first prototype, W4050, flew on 25 November.
Testing Times
By February 1941, the first official test flight took place over Boscombe Down. The sceptics attended, but even they were impressed when the plane reached a top speed of 392mph, as even the newest Spitfire could only manage 374mph. The Mosquito became the fastest plane that Bomber Command had and remained so until 1951. The demonstrations even impressed the American contingent present, but when General Henry Arnold took the idea back to the US and proposed it to a group of their aircraft manufacturers, the opposition was unanimous:
It appears as though this airplane has sacrificed serviceability, structural strength, ease of construction and flying characteristics in an attempt to use construction material which is not suitable for the manufacture of efficient airplanes.
Once official approval was gained from the Air Ministry, production went ahead at the de Havilland factories in Watford. The first 50 aircraft were ready by the summer of 1941. The Mosquito proved itself very quickly and the original order was quickly changed to 20 Photo-Recon (PR) versions and 30 Bomber (B) versions. These unarmed bombers were able to carry a respectable 2,000lbs-worth of explosives and development on the next generation of Mosquitoes was pushed forward. The wings were lengthened, the tail made larger and the engine nacelles4 were made larger. The development also turned up some interesting things.
The Mosquito was a very powerful machine: so powerful that the 'unarmed' idea could be updated. Weapons could be fitted to the aircraft and often were. Large bombs could be carried - like the 'cookie', a 4,000lb monster. The aircraft had shown that it could lift several times the weight that it was designed for, and there are stories of planes being massively overloaded with a ballast of 10,000lbs and still being able to fly. This meant that the plane could not only carry bombs, but also attack enemy aircraft with machine guns or even cannons5.
Such power was the major reason that the Mosquito became one of the most versatile crafts during the Second World War. There are 43 known variants, designed for almost any mission. The only aircraft that had more uses was the German Junkers Ju-88, with up to 60 types. It got to be a dive bomber, which the 'Mozzie' missed out on.
The Wooden Wonder
In 1940 I could at least fly as far as Glasgow in most of my aircraft, but not now! It makes me furious when I see the Mosquito. I turn green and yellow with envy.
-Hermann Göring, Commander-in-Chief of the Luftwaffe, January, 1943
Four main types of Mosquito were used during the war. The plane was firstly a photo-reconnaissance aircraft, fighter/bomber, ground-attack platform and night-fighter. With these four main niches, the DH-98 was an excellent and timely addition to the war effort. However, this was not all that it did: there were a number of other variations, normally only manufactured in small numbers but allowing the Mozzie to do some surprising things.
Photo-Reconnaissance
Even though the Mosquito was envisioned as an unarmed bomber, the uncertain Air Ministry were still sceptical, so the first 50 ordered were to be the Photo-Reconnaissance type. With no armament other than a few cameras, this model depended on its svelte form and speed to out-fly any enemy it came across. The very first Mosquito missions were Photo-Recon over France in the middle of the day. Some squadrons had their machines painted a powder blue to help camouflage them, as they would be flying so high that they would disappear into the wide blue yonder.
Night-Fighter
Technically, the second variation produced was the Mk II night-fighter. It was painted black to hide in the dark, though flying at night slowed the Mozzie down by up to 20mph. Fitted with four nose-mounted .303 Browning machine guns and four chin-mounted6 20mm cannons, it was also equipped with Airborne Interception (AI) radar. After being vectored to the area by ground control, the navigator, watching a small screen, would direct the pilot to the potential enemy planes for identification and possible attack. Later radar innovations required the removal of the 'nasal' machine guns and the addition of an ugly nose-cone, but this didn't diminish the effectiveness of the aircraft.
Bomber
Though, technically, the night-fighter was the second variation, in actuality the bomber holds that honour. The first bombers were just adapted Photo-Recon planes, but soon the Mk IV was being produced. Still unarmed and dependent on lightning quickness, the bombers proved an incredible success, with the Mosquito having the lowest loss rate of any aircraft of RAF Bomber Command during the war. It was used mainly as a 'Pathfinder': that is, it would fly in low and drop flares for larger bombers to sight their own payloads over. The Mk IV was the turning point for the Mosquito, proving the versatility of the plane. It went on to receive bigger engines and bigger nacelles so that it could carry bigger payloads and thus undertake more important missions.
Fighter/Bomber
The fighter/bomber variation of the Mosquito proved to be the most popular. Building on all the improvements in previous types, the fighter/bomber had increased power and weapons (four 20mm cannons mounted in the nose) and armour. Its role was mainly ground support, but the Mosquito could also be used as an intruder7 or heavy bomber escort and, due to its speed, an interceptor. The Mosquito also helped in defending London against the V1 Doodlebug terror attacks and took on the new Luftwaffe jet aircraft like the Messerschmitt Me-262 over Germany during the latter months of the war.
Anti-Ship
Though not a major variation, the anti-ship Mosquito was a fairly effective machine. Taking part in the incredibly dangerous attacks on ships, where you basically fly down the guns, required an extremely competent machine. There were a number of experimental versions, one having the amazing addition of a 57mm cannon in the nose of the plane, along with two .303 Browning machine guns for sighting purposes. This beast lobbed 6lb shells at ships. With the addition of either rockets or bombs on board, the Mosquito claimed a fair number of U-boats and smaller ships.
The Weird and the Wonderful
The Mosquito was so adaptable that it was often used for experimental or one-off variations. One version was designed to carry the 'Highball' bomb. Highball came out of Barnes Wallis' 'bouncing bomb' project to destroy the German industrial Ruhr Valley. Smaller then the massive Dambuster, the Highball was designed as an anti-ship bomb. Shaped like a sphere with the reverse spin of the Dambuster, it proved to be erratic and very susceptible to wind and weather on the open sea, so the project was quickly dropped.
A Plague of Mozzies
The Mosquito was widely used after the Second World War also - the fledgling Israeli Air Force had some success with the aircraft. Between 1951 and 1958, 109 and 110 Squadron of the IAF had about 70 Mosquitoes delivered. They saw action in ground attack, photo-recon and training purposes, before the squadrons were disbanded when the newer French Dassault Mystere arrived.
Other users of the Mosquito included the Royal Australian Air Force, Royal Canadian Air Force, Royal New Zealand Air Force and United States Air Force, but it also saw action with the air forces of Belgium, Burma, China, Czechoslovakia, France, Norway, South Africa, USSR, Sweden, Turkey, Yugoslavia and the Dominican Republic.
Successful Sorties
The Mosquito is memorable not only for the fact that it was a wooden military aircraft, but also for the success of its many varied operational roles. Some of its more famous missions include the following.
Operation Oyster
The largest daylight bombing raid of the war at the time, Operation Oyster was led by Boston and Ventura bombers from 21, 464 and 487 Squadrons. The aim was to disrupt the work being done by Phillips Radio Works in Eindhoven, the Netherlands for the German forces. On 6 December, 1942, Mosquitoes from 105 and 193 Squadrons joined other aircraft off the Dutch coast and proceeded to the target. The radio works soon ground to a halt.
Operation Jericho
Amiens Prison held some 700 inmates, some of them members of the French Resistance, scheduled for execution on 19 February, 1944. Around midday on 18 February, Mosquitoes of the 2nd Tactical Air Force dive-bombed the prison from a height of only sixty feet. The following blast breached the walls of the prison and, while the explosion unfortunately killed 102 prisoners, 258 escaped, including 79 political prisoners. The mission was completed with the loss of only two aircraft and Operation Jericho proved that the Mosquito was able to perform precision bombing raids.
Opportunistic Missions
Mosquitoes were also used by many squadrons in a variety of ways. Some targeted Nazi rallies in Berlin and others took on the Gestapo. Many concentrated their efforts on factories and transport links such as trains and railways. Other squadrons developed successful methods for destroying shipping and U-boats. After the war, Mosquitoes were also utilised in Operation Manna, which was a humanitarian exercise that involved dropping food and supplies to many people throughout the Netherlands.
Mosquitoes that Still Buzz
The finest examples of Mosquitoes can be seen at the de Havilland Aircraft Heritage Centre, Imperial War Museum - Duxford, the RAF Museum, Hendon or the Australian War Memorial, Canberra.
If you can't get out to see a Mosquito, you could find a copy of the film 633 Squadron (1964), which tells the fictional story of a squadron of Mosquito crews on their mission to knock out a German fuel dump in Norway.
Of course, since the Mosquito was manufactured mostly from wood and glue, you could try building your very own. However, this project might be a little too much for some, so the plastic and glue variants available in most good toy stores should keep even the most avid Mozzie enthusiast happy!