A design team led by R. E. Bishop with C. T. Wilkins assisting, was assembled with the aim of developing the D.H. 101, which was initially pursued as a private venture.

[1] By November 1942, de Havilland had elected to shelve the night bomber project and concentrate on producing a long-range fighter, the D.H. 103, that would make the maximum possible use of the Merlin engine.

[1] The D.H. 103 resembled a small Mosquito, with a single seat; it was intended to take on other single-seat fighter aircraft, particularly those operated by Japan, while still being capable of conducting very long range missions to be of use in the Pacific Theatre.

Priority was given early on to ensuring that such adaptation could be readily done: measures for ease of control, especially when flown at low speeds, were incorporated and attention paid to providing the pilot with a high level of visibility.

[3] The two propellers were driven in opposite directions to improve take-off and landing characteristics and high-drag flaps were integrated to provide for greater power during approaches.

[5] Towards the end of 1944, the assembly line for the Hornet F.1, the initial production model, was being established at Hatfield and orders had already been received for the Royal Air Force (RAF).

[7] PX239, originally built as a Hornet F.20, was outfitted with power-operated folding wings and a large dorsal fillet, which was later fitted to all production aircraft to comply with a new requirement to provide "feet off" directional stability with one engine stopped.

The requirement for these aircraft lapsed with the end of the Second World War in the Pacific; all were used in arrester barrier trials at Boscombe Down and scrapped before entering RAF service.

Because the Hornet used the American "3-point" system of catapult-assisted takeoff, two forged steel catapult bridle hooks were fitted, one below each wing, close to the fuselage.

Other specialised naval equipment (mainly different radio gear) was fitted and provision was made for three camera ports, one on each side of the rear fuselage and one pointing down.

Special flame-dampening exhausts were installed, and a second basic cockpit was added to the rear fuselage, just above the wing trailing edges.

At the front of the aircraft, the nose underwent a transformation with the small rotating ASH radar dish being housed under an elongated "thimble" radome.

It had originally been dispatched to Edmonton, Alberta, Canada to conduct winter trials; following these tests, TT193 was sold rather than be transported back to England.

Registered CF-GUO, the aircraft was operated by Spartan Air Services and Kenting Aviation until 11 July 1952 when an engine failure caused a forced landing at Terrace, British Columbia.

37 years later, he was still impressed: "In level flight the Sea Hornet's stability about all axes was just satisfactory, characteristic, of course, of a good day interceptor fighter.

[1] The Hornet's principal armament was four short-barrelled 20 mm (.79 in) Hispano V cannons, while other typical weapon loads included various rockets and bombs.

[20] Fuselage construction was identical to the earlier Mosquito: a balsa wood "pith" sandwiched between plywood sheets which were laid in diagonal panels.

[21] The fuselage halves were built on large concrete or wood patterns and equipment was fitted in each half; they were then joined along the top and bottom centre lines using wooden reinforcing strips.

[22] The horizontal tail unit was an all-metal structure, again featuring the distinctive de Havilland shape,[14] which was later repeated on the Chipmunk and Beaver.

Construction was of mixed balsa/plywood similar to the Mosquito but the Hornet differed in incorporating stressed Alclad lower-wing skins bonded to the wooden upper wing structure using the new adhesive Redux.

[14] Apart from the revised structure, the Hornet's wings were a synthesis of aerodynamic knowledge that had been gathered since the design of the Mosquito, being much thinner in cross-section, and with a laminar flow profile similar to the P-51 Mustang and Hawker Tempest.

De Havilland tried propellers that rotated outward at the tops of their arcs (as in the P-38 Lightning),[25] but this configuration blanketed the fin and reduced rudder effectiveness at low speeds, compromising ground handling.

[26][22] Because of the revised induction arrangements of the Merlin 130 series, the supercharger and carburettor air intakes could be placed in the leading edges of the wings, outboard of the nacelles.

[14] To assist airflow over the wing, the engine nacelles were mounted low, which meant that the undercarriage legs were reasonably short and the pilot's field of view was improved.

[22] To further aid the pilot's field of view, the unpressurised cockpit was mounted well forward in the fuselage and was housed under an aft-sliding perspex blister canopy.

[29] On 30 July 1949, PX286 participated in the National Air Races (GB) at Elmdon; when flown by Geoffrey Pike, it clocked the fastest lap at 369 mph (594 km/h) and attained second place overall.

Upon arrival, the Hornets were promptly used to replace Bristol Beaufighters and Supermarine Spitfires that were being operated in support of ground security forces against Communist guerrillas fighting in the region.

[11][29] On 23 July 1954, two Hornets from RAF Kai Tak in Hong Kong were the first to arrive on the scene of a shootdown of a Cathay Pacific Skymaster off the coast of Hainan Island.

[7] After relocating to Arbroath, the squadron participated in numerous trials for the type prior to the Sea Hornet's first seaborne deployment, having embarked upon HMS Implacable in 1949.

During the North American tour, multiple Sea Hornets performed several spectacular flying displays at the International Air Exposition in New York City between 31 July and 8 August.