Hawker Horsley

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

The Hawker Horsley was a British single-engined biplane bomber of the 1920s. It
was the last all-wooden aircraft built by Hawker Aircraft, and served as a
medium day bomber and torpedo bomber with Britain's Royal Air Force between 1926
and 1935, as well as the navies of Greece and Denmark.

The Horsley (named after Sir Thomas Sopwith's home of Horsley Towers) was
originally designed to meet Air Ministry Specification 26/23 for a day bomber
powered by a single Rolls-Royce Condor engine. While the specification called
for any production aircraft to be of metal construction, Hawker proposed to
build the prototype of wooden construction, gradually switching to a metal
structure during production. This was acceptable to the Air Ministry, and an
order for a single prototype was placed. The first prototype was flown in March
1925, powered by a 650 hp (480 kW) engine, and was delivered to the Aeroplane
and Armament Experimental Establishment at Martlesham Heath on 4 May 1925.

Meanwhile, the Air Ministry revised its requirements, producing Specification
23/25 which increased the required payload from one to two 551 lb (250 kg)
bombs. At the same time, it also issued Specification 24/25 for a torpedo
bomber, required to carry a 2,150 lb (980 kg)) torpedo. The Horsley's ability to
cope with the increased loads required to meet these new specifications led to
the design being favoured by the RAF, with an initial order of forty aircraft,
consisting of ten wooden Mk Is and 30 Mk IIs of mixed metal and wood
construction, being placed.

The Horsley was a large single-engined two-bay biplane. It had a crew of two,
comprising a pilot and a gunner/bomb-aimer/radio operator, who had a .303 in
(7.7 mm) Lewis gun mounted in a Scarff ring in the rear cockpit and a prone
position for bomb aiming. The rear cockpit was also fitted with dual controls.
The payload included two 551 kg (1,215 lb) bombs, one 1,500 lb (680 kg) bomb or
a torpedo weighing 2,800 lb (1,300 kg).

The structure was originally all wood, but before production was complete an
all-metal structure was introduced, made in what became the famous Hawker system
of metal construction. The three methods of construction were designated:
Horsley Mk I for the all-wooden aircraft, Horsley Mk II for the mixed material,
and (unofficially) Horsley III for the all-metal aircraft. Some aircraft were
fitted with floats.

Two aircraft, known as the Hawker Dantorp and powered by Leopard II engines were
sold to the Danish Government. They had a slightly different fuselage,
accommodating a third crew member. The Danes also purchased a licence to build a
further ten aircraft at the Danish Naval Workshops (Orlogsvaerftet), but these
were not built owing to a shortage of funds.

Production aircraft were powered by the Condor IIIA, but the Horsley was also
much used as a flying testbed for other engines, including the Napier Lion,
Rolls-Royce Buzzard, Rolls-Royce Eagle, the Armstrong Siddeley Leopard radial
engine, the Junkers Jumo diesel engine and early versions of the Rolls-Royce
Merlin.


Role
Medium bomber

Manufacturer
Hawker Aircraft

First flight
1925

Introduction
January 1927

Retired
1935

Primary user
RAF

Number built
124

Variants
Hawker Dantorp

The first aircraft were delivered to No 100 (Bomber) Squadron of the Royal Air
Force in September 1927, with two more squadrons, No. 15 and No. 11 Squadrons
receiving Horsleys by the end of the year, replacing the Fairey Fawn. The
Horsleys proved greatly superior to the Fawn, carrying up to three times the
bomb load over greater ranges and at higher speeds, while also being agile for
their size, and were popular with their pilots.

Horsley was chosen to attempt a non-stop flight to India, with a specially
modified aircraft, carrying much more fuel and taking off at a weight of over
14,000 lb (6,350 kg) took off from RAF Cranwell on 20 May 1927, flown by Flight
Lieutenants Roderick Carr and L.E.M Gillman. It ran out of fuel en route,
however, ditching in the Persian Gulf near Bandar Abbas, Iran. Despite this it
had covered a distance of 3,420 mi (5,500 km), which was sufficient to set a new
world distance record, but was beaten in turn within a few hours by Charles
Lindbergh, whose solo Atlantic flight between New York and Paris in the Spirit
of St. Louis covered 3,590 mi (5,780 km)).

The Horsleys remained in service in the day-bombing role until 1934, with 504
Squadron's Horsleys being replaced by Westland Wallaces in March 1934. No 36
Squadron at Singapore retained the Horsely in the Torpedo bomber role until July
1935. The last Horsley, a Merlin-powered testbed flew its final flight at RAE
Farnborough on 7 March 1938.

A total of 124 Horsleys were built, including six aircraft for the Hellenic
Naval Air Service and the two related Dantorps built for Denmark.

Specification (Horsley II day bomber)

General characteristics
Crew: 2, pilot and bomb-aimer/gunner
Length: 38 ft 10 in (11.84 m)
Wingspan: 56 ft 5 3/4 in (17.215 m)
Height: 13 ft 8 in (4.17 m)
Wing area: 693 sq ft (64.4 m2)
Empty weight: 4,760 lb (2,159 kg) (4,958 lb (2,249 kg) for torpedo bomber)
Gross weight: 7,800 lb (3,538 kg) (9,270 lb (4,200 kg) for torpedo bomber)
Fuel capacity: 230 imp gal (280 US gal; 1,000 L)
Powerplant: 1 × Rolls Royce Condor IIIA water-cooled V12 engine, 665 hp (496 kW)
Propellers: 2-bladed Watts wooden propeller, 14 ft 6 in (4.42 m) diameter

Performance
Maximum speed: 125 mph (201 km/h, 109 kn) at 6,000 ft (1,800 m)
Range: 900 mi (1,400 km, 780 nmi)
Endurance: approx. 10 hr
Service ceiling: 14,000 ft (4,300 m)
Time to altitude: 14 min 20 s to 10,000 ft (3,000 m)

Armament

Guns:
1 × forward-firing .303 in (7.7 mm) Vickers machine gun
1 × rear-mounted .303 in (7.7 mm) Lewis Gun

Bombs: 1,500 lb (680 kg) bombload or 1 × torpedo




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