de Havilland DH.103 Hornet

https://en.wikipedia.org/wiki/De_Havilland_Hornet

The de Havilland DH.103 Hornet, developed by de Havilland, was a fighter
aircraft driven by two piston engines. It further exploited the wooden
construction techniques that had been pioneered by the de Havilland Mosquito.
Development of the Hornet had started during the Second World War as a private
venture. The aircraft was to conduct long range fighter operations in the
Pacific Theatre against the Empire of Japan but the war ended before the Hornet
reached operational squadron status.

The Hornet entered service with RAF Fighter Command where it equipped several
day fighter units and was commonly stationed in the British mainland. It saw
combat in the Far East, being used as a strike fighter as part of the British
military action taken during the Malayan Emergency. A naval carrier-capable
version, the Sea Hornet, had been envisioned early on and was procured by the
Fleet Air Arm of the Royal Navy.

Sea Hornet F.20, NF.21 and PR.22

The Hornet was designed with the possibility of naval service on carriers firmly
in mind. To this end good low-speed handling was required, along with good
all-round visibility for the pilot. The basic Hornet design excelled at meeting
these requirements. Shortly after the first Hornet prototype flew, Specification
N.5/44 was issued to de Havilland, covering the modification of the Hornet for
naval service. The Heston Aircraft Company was contracted to carry out the
conversion work on three early production F.1s. The work entailed altering the
wings to incorporate folding mechanisms so that each outer wing panel, from the
aileron/flap line outboard could be folded upwards and inwards at an angle. The
hinges were part of the upper wing skin structure while the lower wing skins
incorporated securing latches, and Lockheed hydraulic jacks were used to move
the wing panels. Slotted flaps were introduced to improve low speed "flaps down"
control.

Merlin 133/134s (derated from 2,070 hp (1,540 kW) to 2,030 hp (1,510 kW)) were
fitted to all Sea Hornets. 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. Sea Hornet F.20s also
incorporated the modifications of the Hornet F.3, although the internal fuel
capacity was 347 Imp gal (1,557 l), slightly reduced from that of the F.1. The
modifications added some 550 lb (249 kg) to the weight of the aircraft. Maximum
speed was decreased by 11 mph (18 km/h).

The Hornet NF.21 was designed to fill a need for a naval night fighter. Special
flame-dampening exhausts were installed, and a second basic cockpit was added to
the rear fuselage, just above the wing trailing edges. ASH radar equipment was
placed in the rear of this cockpit, with the radar operator/navigator seated
facing aft. To gain access, a small trapdoor was provided in the lower fuselage;
a fixed, teardrop-shaped bubble canopy, which could be jettisoned in an
emergency, provided a good field of view. 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. The horizontal tail units were increased in
span. The effect of these modifications on performance was minimal; about 4 mph
(6 km/h).

The Sea Hornet PR.22 was a dedicated photo reconnaissance aircraft version of
the F.20. The cannon were removed and the apertures faired over. Three cameras
were installed in the rear fuselage: two F.52s for night use and one K.19B for
day. A total of 23 PR.22s were built, interspersed with F.20s being built at
Hatfield.

Design

The de Havilland Hornet bore a family resemblance to the larger Mosquito, but it
was an entirely fresh design albeit one that drew extensively upon experiences
from, and the design of, the Mosquito. It was powered by a pair of highly
developed Rolls-Royce Merlin engines, producing 2,070 hp (1,540 kW) each, which
drove four-bladed propellers (manufactured by de Havilland Propellers).
According to aviation author P.J. Birtles, the efficiency and power of this
configuration gave the Hornet "a higher performance than any other propeller
driven aircraft". 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.

Fuselage construction was identical to the earlier Mosquito: a balsa wood "pith"
sandwiched between plywood sheets which were laid in diagonal panels. Aerolite
formaldehyde cement was the bonding agent. 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. The entire fuselage was then tightly wrapped in fine aviation fabric
which was doped in place. The tailfin which had the trademark gracefully-curved
de Havilland shape, was an integral part of the rear fuselage. On late F.1s and
further models of production aircraft, a fin fillet was added to the base of the
unit. The horizontal tail unit was an all-metal structure, again featuring the
distinctive de Havilland shape, 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. The two wing spars were
redesigned to withstand a higher load factor of 10 versus 8. 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. The control surfaces consisted of hydraulically-operated split
flaps extending from the wing root to outboard of the engine nacelles; as on the
Mosquito, the rear of the nacelle was part of the flap structure. Outboard, the
Alclad-covered ailerons extended close to the clipped wing tips and gave
excellent roll control.


Flying the Sea Hornet

Just after VE Day the first semi-naval Sea Hornet PX 212 arrived at the RAE,
Farnborough. Eric Brown initiated "work-up to deck-landing" trials. 37 years
later, he was still impressed:

"...the next two months of handling and deck landing assessment trials were to
be an absolute joy; from the outset the Sea Hornet was a winner!""The view from
the cockpit, positioned right forward in the nose beneath a one-piece
aft-sliding canopy was truly magnificent. The Sea Hornet was easy to taxi, with
powerful brakes... the takeoff using 25 lb (2,053 mm Hg, 51" Hg) boost and flaps
at one-third extension was remarkable! The 2,070 hp (1,540 kW) Merlin 130/131
engines fitted to the prototypes were to be derated to 18 lb (1,691 Hg, 37" Hg)
boost and 2,030 hp (1,510 kW) as Merlin 133/134s in production Sea Hornets, but
takeoff performance was to remain fantastic. Climb with 18 lb boost exceeded
4,000 ft/min (1,200 m/min)"...

"In level flight the Sea Hornet's stability about all axes was just
satisfactory, characteristic, of course, of a good day interceptor fighter. Its
stalling characteristics were innocuous, with a fair amount of elevator
buffeting and aileron twitching preceding the actual stall"...

"For aerobatics the Sea Hornet was absolute bliss. The excess of power was such
that manoeuvres in the vertical plane can only be described as rocket-like. Even
with one propeller feathered the Hornet could loop with the best single-engine
fighter, and its aerodynamic cleanliness was such that I delighted in its
demonstration by diving with both engines at full bore and feathering both
propellers before pulling up into a loop!"

During this series of tests Captain Brown found that the ailerons were too heavy
and ineffectual for deck landing and there were some problems with throttle
movement, brakes and the rubber-in-compression undercarriage legs were still
fitted. De Havilland were quick to modify the aircraft. Eric Brown:

"Landings aboard Ocean had been made without any crash barrier... Yet, in the
case of the Sea Hornet, I had felt such absolute confidence that I was mentally
relaxed... Indeed, there was something about the Sea Hornet that made me feel
that I had total mastery of it; I revelled in its sleek form and the immense
surge of power always to hand...""Circumstances had conspired against the Sea
Hornet in obtaining the recognition that it justly deserved as a truly
outstanding warplane...in my book the Sea Hornet ranks second to none for
harmony of control, performance characteristics and, perhaps most important, in
inspiring confidence in its pilot. For sheer exhilarating flying enjoyment, no
aircraft has ever made a deeper impression on me than did this outstanding filly
from the de Havilland stable.


Role
Land and naval-based fighter aircraft

National origin
United Kingdom

Manufacturer
de Havilland

First flight
28 July 1944

Introduction
1946

Retired
1956

Primary users
Royal Air Force
Royal Navy

Produced
1945 to 1950

Number built
383

Sea Hornet

On 1 June 1947, 801 Squadron was reformed to become the first squadron to
operate the Sea Hornet, based at RNAS Ford. 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. In 1951,
a further transfer was made to HMS Indomitable: during their time on board the
Sea Hornets contributed to a multinational maritime exercises as long-range
fighter escort and strike aircraft; however, in June 1951, they were replaced by
single-engined Hawker Sea Furies.

Further Sea Hornet deliveries were attached to various Naval Squadrons,
including three which were attached to 806 Squadron in 1948 which, along with a
Vampire and two Sea Furies, were embarked on HMCS Magnificent for a tour of
North America in 1948. 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. In mid-1948, one Sea
Hornet, PX219, was adapted to carry 2 × Highballs in an installation that was
developed but not applied to the fleet. The equipment was removed during January
1949 and it is currently unknown if the Hornet ever dropped a Highball during
flight.

Specifications (Hornet F.1)

General characteristics
Crew: 1
Length: 35 ft 6 in (10.82 m)
Wingspan: 45 ft (14 m)
Height: 14 ft 2 in (4.32 m)
Wing area: 361 sq ft (33.5 m2)
Airfoil: EC1240
Empty weight: 11,292 lb (5,122 kg)
Gross weight: 15,820 lb (7,176 kg)
Max takeoff weight: 18,250 lb (8,278 kg) with 2x 200 imp gal (240 US gal; 910 l)
drop-tanks
Powerplant: 2 × Rolls-Royce Merlin 130 / 131 (left-hand and right-hand rotation)
V-12 liquid-cooled piston engines, 2,070 hp (1,540 kW) each
Propellers: 4-bladed De Havilland constant-speed propellers (left-hand and
right-hand rotation)

Performance
Maximum speed: 475 mph (764 km/h, 413 kn) at 21,000 ft (6,400.8 m)
Cruise speed: 270 mph (430 km/h, 230 kn) at 20,000 ft (6,096.0 m)
Range: 1,480 mi (2,380 km, 1,290 nmi)
Ferry range: 2,600 mi (4,200 km, 2,300 nmi)
Service ceiling: 41,500 ft (12,600 m)
Time to altitude: 20,000 ft (6,096.0 m) in 4 minutes
Wing loading: 43.82 lb/sq ft (213.9 kg/m2)

Armament

4 × 20 mm (.79 in) Hispano Mk. V cannon (with 190 rpg) in lower fuselage nose
2 × 1,000 lb (454 kg) bombs under wing, outboard of engines
8 × 60 lb (27 kg) RP-3 unguided rockets (Hornet F.3)

Avionics
(ASH radar fitted in Sea Hornet NF Mk 21.)




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