The de Havilland DH.98 Mosquito was a British fighter-bomber and reconnaissance aircraft.
The de Havilland had a crew of two men and dual Rolls Royce Merlin Engines that were capable of propelling it at speeds of up to 610 kilometers per hour. The DH.98s armament consisted of four 7.7mm Browning machine guns and four autocannons. The DH.98 also depending on the variant could carry a number of other weapons such as bombs or torpedoes.
The total length of the DH.98 was 12.4 meters while the total weight of the Mosquito was about 6,400 kilograms. This low weight caused by the fact that the Mosquito was largely made of wood allowed it to travel at high speeds. An unexpected bonus from the wooden construction was that the DH.98 was largely undetectable by radar.
The possibility of developing a fast bomber was first investigated by the de Havilland Aircraft Company in the summer of 1938. In October of that year, discussion of a number of proposals by the design team, led by Geoffrey de Haviland and including Chief Designer R. E. Bishop and Chief Engineer C. C. Walker resulted in a proposal for a twin engine wooden bomber with two crew and, at least in the bomber and reconnaissance versions, no fixed armament. This was accepted on 29 December 1939, and the first contract was placed on 1 March 1940, for fifty DH.98 bombers (including prototypes) built to Specification B.1/40. This had been written around the proposals submitted by de Havilland, with the aircraft being named Mosquito after the gnat like fly of the genus Culex, noted for it's vicious sting.
Following the fall of France, and the evacuation from Dunkirk, the Mosquito was dropped from the Ministry of Aircraft Production programme, only to be reinstated later due to the use of non strategic material in the design, and then only at a lower priority than production of the Tiger Moth and Oxford.
Despite repeated delays due to Luftwaffe bombing in the area of the Hatfield factory, the first of three prototypes (W4050) was flown in Mk.IV bomber configuration by Geoffrey de Havilland on 25 November 1940, less than eleven months after the start of detail design work. This aircraft was handed over for official trials on 19 February 1941. These proved so successful that the only modification required led to extension of the rear of the engine nacelles, in order to improve airflow.
Following adjustment of the contract, which now covered twenty bombers and thirty fighters, a Mk.II fighter prototype (W4052) was built at Salisbury Hall, the dispersal site for the Hatfield design office and experimental shop, and made its first flight from a 450-yard filed next to the production building on 15 May 1941. This was followed into the air by W5041, prototype of the Mk.I Photo-reconnaissance on 10 June 1941.
The de Havilland Mosquito saw service in the European Theater, as a night fighter, bomber, anti-submarine fighter, reconnaissance and various other roles. It was used to intercept Luftwaffe raids on Great Britain. It also was involved in Operation: Overlord and Operation: Jericho.
- PR.l: Unarmed photo-reconnaissance, with span lengthened from 52 ft 6in of prototype to 54 ft 2in but still with short engine nacelles.
- F.ll: Night fighter, with pilot and observer side by side. flat bulleteproof windscreen. extended nacelles (as in all subsequent aircraft. with flaps divided into inner and outer segments) and armament of four 20mm Hispano cannon with 300 rounds each under the floor and four 0.303in Brownings with 2.000 rounds each in the nose. First flew 15 May 1941; subsequently fitted with Al Mk IV or V radar or Turbinlight searchlight.
- T.III: Dual-control trainer. first flown January 1942 but produced mainly after the war (last delivery 1949).
- B.lV: Unarmed bomber, carrying four 500 lb (227 kg) bombs internally; first delivered to 105 Sqn at Swanton Morley November 1941. making first operational sortie (Cologne, the morning after the first 1.000-bomber night attack) on 31 May 1942. Some later fitted with bulged bomb bays for 4.000 lb (1814 kg) bomb. Others were modified to carry a pair of Highball bouncing bombs.
- FB.Vl: Fighter-bomber and intruder. by day or night; same guns as F.II but two 25Olb (113 kg) bombs in rear bay and two more (later two 500 lb) on wing racks; alternatively, 50 or 100 gal drop tanks, mines. depth charges or eight 60 lb rockets. Some fitted with Al radar. Total production 2.584, more than any other mark.
- B.Vll: Canadian—built Mk lV. used in North America only.
- PR.VIII: Reconnaissance conversion of B.lV with high-b|own Merlin 61.
- Mk IX: Important advance in bomber (B.lX) and reconnaissance (PR.lX) versions; high-blown two~stage engines. bulged bomb bay for 4.000 lb bomb or extra fuel. much increased weight, paddle-blade propellers and new avionics (Rebecca. Boozer. Oboe or H25 Mk Vl).
- NF.Xll: Conversion of F.ll fitted with new thimble nose containing Al Mk VIII centimetric radar in place of Brownings.
- NF.XIII: Similar to Mk XII but built as new. with thimble or bull nose and same wing as Mk Vl for drop tanks or other stores; flew August 1943.
- NF.XV: High-altitude fighter with wings extended to 59 ft, pressurised cockpit, lightened structure, Al Mk VIII in nose and belly pack of four 0.303in Brownings to combat Ju 86P raiders.
- Mk XVI: Further major advance with two-stage Merlins, bulged bomb bay and pressurised cockpit. PR.XVI flew July 1943; B.XVI in January 1944. Over 1,200 of latter being used for high-level nuisance raids with 4.000 lb bombs.
- NF.XVll: Night fighter with new Al Mk X or SCR.72O (some with tail-looking scanner also); four 20mm each with 500 rounds.
- FB.XVIII: Dubbed Tse~Tse Fly, this multi-role Coastal Command fighter had low-blown engines and carried a 57mm six-pounder Molins gun with 25 rounds plus four Brownings, as well as eight 60 lb rockets or bombs.
- NFXIX: Mk XIII developed with Al.VllI or X or SCR.72O in bulged Universal nose and low-blown Merlin 25s.
- B.XX: Canadian—built B.lV (USAAF designation F-8).
- FB.21 to T.29: Canadian marks with Packard V-1650 (Merlin) engines, not all built.
- NF.30: Night fighter with two-stage engines, paddle blades, AI Mk X and various sensing, spoofing or jamming avionics; based on Mk XIX.
- PR.32: Extended-span reconnaissance version with Merlin 113/114.
- Mk.33: First Royal Navy Sea Mosquito version, with power-foIding wings. Oleo main legs (in place of rubber in compression), low-blown engines driving four~blade propellers, arrester hook, four 20mm cannon, torpedo (or various bomb/rocket loads), American ASH radar and rocket JATO boost.
- PR.34: Strategic reconnaissance version, with 113/114 engines, extra-bulged belly for 1,269 gal fuel (200gal drop tanks) and pressure cabin.
- B.35: Equivalent bomber version, with PR and target-tug offshoots.
- NF.36: Postwar fighter, with 113/114 engines and AI Mk X.
- TF.37: Naval torpedo-ﬁghter; basically Mk 33 with Al/ASV Mk XIII.
- NF.38: Final fighter, mainly exported; Al Mk IX, forward cockpit.
- TT.39: Complete rebuild by General Aircraft as specialised target tug.
- FB.40: Australian-built Mk VI, with PR.4O as conversions.
- FR.41: Australian-built derivative of PR.IX and Mk 40.
- T.43: Australian trainer; all Australian production had Packard engines.
- Green, William. Famous Bombers of the Second World War. Purnell Book Services. 1975. Page 66
- Green, William. Famous Fighters of the Second World War. Purnell Book Services. 1975. Page 230
- Green, William - Bombers. Page 67
- Green, William - Fighters. Pages 230-231
- Green, William - Fighters. Page 231
- Gunston, Bill. Illustrated Directory of Fighting Aircraft of World War II. Salamander Books. 1988. ISBN 0-86101-390-5 Pages 32 and 33