One of the truly great stories of the second world war was that of the Mosquito fighter-bombers, there contribution to saving Britain from Germany and their unique method of construction and manufacturing.
Role
Fast bomber
Fighter-bomber
Night fighter
Maritime strike aircraft
Fast photo-reconnaissance aircraft
Manufacturer
de Havilland Aircraft Company
First flight
25 November 1940
The de Havilland DH.98 Mosquito was a British multi-role combat aircraft with a two-man crew that served during the Second World War and the postwar era. The Mosquito was one of the few operational front-line aircraft of the World War II era to be constructed almost entirely of wood and, as such, was nicknamed "The Wooden Wonder". The Mosquito was also known affectionately as the "Mossie" to its crews Originally conceived as an unarmed fast bomber, the Mosquito was adapted to many other roles during the air war, including low- to medium-altitude daytime tactical bomber, high-altitude night bomber, pathfinder, day or night fighter, fighter-bomber, intruder, maritime strike aircraft, and fast photo-reconnaissance aircraft. It was also used by the British Overseas Airways Corporation (BOAC) as a transport.
When the Mosquito entered production in 1941, it was one of the fastest operational aircraft in the world. Entering widespread service in 1942, the Mosquito first operated as a high-speed, high-altitude photo-reconnaissance aircraft, and continued to operate in this role throughout the war. From mid-1942 to mid-1943 Mosquito bombers were used in high-speed, medium- or low-altitude missions, attacking factories, railways and other pinpoint targets within Germany and German-occupied Europe. From late 1943, Mosquito bomber units were formed into the Light Night Strike Force and used as pathfinders for RAF Bomber Command's heavy-bomber raids. They were also used as "nuisance" bombers, often dropping 4,000 lb (1,812 kg) "cookies", in high-altitude, high-speed raids that German night fighters were almost powerless to intercept.
As a night fighter, from mid-1942, the Mosquito was used to intercept Luftwaffe raids on the United Kingdom, most notably defeating the German aerial offensive, Operation Steinbock, in 1944. Offensively, starting in July 1942, some Mosquito night-fighter units conducted intruder raids over Luftwaffe airfields and, as part of 100 Group, the Mosquito was used as a night fighter and intruder in support of RAF Bomber Command's heavy bombers, and played an important role in reducing bomber losses during 1944 and 1945. As a fighter-bomber in the Second Tactical Air Force, the Mosquito took part in "special raids", such as the attack on Amiens Prison in early 1944, and in other precision attacks against Gestapo or German intelligence and security forces. Second Tactical Air Force Mosquitos also played an important role operating in tactical support of the British Army during the 1944 Normandy Campaign. From 1943 Mosquitos were used by RAF Coastal Command strike squadrons, attacking Kriegsmarine U-boats (particularly in the 1943 Bay of Biscay offensive, where significant numbers of U-boats were sunk or damaged) and intercepting transport ship concentrations.
The oval-section fuselage was a frameless monocoque shell built in two halves being formed to shape by band clamps over a mahogany or concrete mould, each holding one half of the fuselage, split vertically. The shell halves were made of sheets of Ecuadorean balsawood sandwiched between sheets of Canadian birch, but in areas needing extra strength— such as along cut-outs— stronger woods replaced the balsa filler; the overall thickness of the birch and balsa sandwich skin was only 7⁄16 inches (11 mm). This sandwich skin was so stiff that no internal reinforcement was necessary from the wing's rear spar to the tail bearing bulkhead. The join was along the vertical centre line. This split construction greatly aided the assembly of the internal equipment as it allowed the technicians easy access to the fuselage interior. While the glue in the plywood skin dried, carpenters cut a sawtooth joint into the edges of the fuselage shells, while other workers installed the controls and cabling on the inside wall. When the glue completely dried, the two halves were glued and screwed together. The fuselage was strengthened internally by seven bulkheads made up of two plywood skins parted by spruce blocks, which formed the basis on each half for the outer shell. Each bulkhead was a repeat of the spruce design for the fuselage halves; a balsa sheet sandwich between two plywood sheets/skins. Bulkhead number seven carried the fittings and loads for the tailplane and rudder, The type of glue originally used was Casein resin, which was later replaced by "Aerolite", a synthetic urea-formaldehyde, which was more durable. Many other types of screws and flanges (made of various woods) also held the structure together.
The fuselage construction joints were made from balsa wood and plywood strips with the spruce multi-ply being connected by a balsa V joint, along with the interior frame. The spruce would be reinforced by plywood strips at the point where the two halves joined to form the V-joint. Located on top of the joint the plywood formed the outer skin. During the joining of the two halves ("boxing up"), two laminated wooden clamps would be used in the after portion of the fuselage to act as support. A covering of doped Madapolam (a fine plain woven cotton) fabric was stretched tightly over the shell and a coat of silver dope was applied, after which the exterior camouflage was applied. The fuselage had a large ventral section cut-out, which was braced during construction, to allow it to be lowered onto the wing centre-section. Once the wing was secured the lower panels were replaced, and the bomb bay or armament doors fitted.
The all-wood wing was built as a one-piece structure and was not divided into separate construction sections. It was made up of two main spars, spruce and plywood compression ribs, stringers, and a plywood covering. The outer plywood skin was covered and doped like the fuselage. The wing was installed into the roots by means of four large attachment points. The engine radiators were fitted in the inner wing, just outboard of the fuselage on either side. These gave less drag. The radiators themselves were split into three sections: an oil cooler section outboard, the middle section forming the coolant radiator and the inboard section serving the cabin heater. The wing contained metal framed and skinned ailerons, but the flaps were made of wood and were hydraulically controlled. The nacelles were mostly wood, although, for strength, the engine mounts were all metal as were the undercarriage parts. Engine mounts of welded steel tube were added, along with simple landing gear oleos filled with rubber blocks. Wood was used to carry only in-plane loads, with metal fittings used for all triaxially loaded components such as landing gear, engine mounts, control surface mounting brackets, and the wing-to-fuselage junction. The outer leading wing edge had to be brought 22 inches (56 cm) further forward to accommodate this design.The main tail unit was all wood built. The control surfaces, the rudder and elevator were aluminium framed and fabric covered. The total weight of metal castings and forgings used in the aircraft was only 280 lb (130 kg).
Would or could the world ever see another aircraft developed and built such as the Mosquitos? I doubt it, but it just goes to show you what skilled craftsman can do when given the tools and design concepts to work with!
