Supermarine Type 224
| Supermarine Type 224 | |
|---|---|
| General information | |
| Other name(s) | Spitfire |
| Type | Fighter aircraft |
| National origin | United Kingdom |
| Manufacturer | Supermarine |
| Designer | Team led by R. J. Mitchell |
| Management | Royal Air Force |
| Number built | 1 |
| History | |
| First flight | 19 February 1934 |
| Fate | Destroyed in 1937 (target practice) |
The Supermarine Type 224 was a British gull-wing monoplane fighter aircraft designed by R.J. Mitchell at Supermarine in response to Air Ministry Specification F.7/30, which sought to introduce a new fighter to succeed the Gloster Gauntlet. The Type 224 was powered by a Rolls-Royce Goshawk engine, which used an experimental evaporative cooling system.
Problems with the cooling system, combined with its disappointing performance during trials, led to the Type 224 being rejected by the Air Ministry, a contract for production aircraft eventually going to the Gloster Gladiator. The type is nevertheless notable because Mitchell learnt lessons from its design that were to contribute to his success with the Supermarine Spitfire.
Design and development
Air Ministry Specification F.7/30, which developed from O.R.1,[1] was formally issued to the British aircraft industry in October 1931, called for an all-metal day and night fighter aircraft armed with four machine guns, a high maximum speed and rate of climb, and a landing speed of less than 60 miles per hour (97 km/h). The importance of good visibility from the cockpit was specified. Although the use of any suitable engine was permitted, the Air Ministry expressed a preference for the Rolls-Royce Goshawk, then still being developed.[citation needed]
Of the many proposals submitted by manufacturers, three were selected for official development as prototypes, the Supermarine 224 among them. In addition, privately funded submissions for the competition were encouraged. R. J. Mitchell, Supermarine's designer, came up with a clean-looking inverted gull-wing monoplane powered by the 600 hp Goshawk II with a fixed undercarriage.[citation needed]
The gull wing configuration was chosen in order to shorten the undercarriage legs and so reduce drag, but since this configuration was known to be liable to produce problems with lateral stability an extensive programme of wind-tunnel testing using models was carried out before arriving at the final design. These tests also revealed a lack of directional stability: Mitchell accordingly enlarged the fin area.[citation needed]
The cockpit was open, and further wind-tunnel tests were also carried out on a full-size model of the cockpit area to ensure that the pilot would not be subjected to undue buffeting. The fuselage was of monocoque construction, with one pair of guns mounted either side of the cockpit and the other pair in the 'trouser' fairings of the undercarriage.[citation needed]
The wing was of unusual construction, having a single main spar, forward of which the condensers of the engine cooling system formed the entire leading edge of the wing, the combination of the two producing a 'D-box' spar of great torsional rigidity. Behind the main spar the wing was fabric-covered.[citation needed]
The evaporative cooling system used by the Goshawk involved allowing the cooling water to reach a temperature greater than 100 °C without boiling by keeping it under pressure while circulating through the engine: this superheated water was then allowed to boil off by releasing the pressure, the resulting steam then being cooled in a condenser, collected as water and then recirculated through the engine.[citation needed]
The system had been experimentally flown in other aircraft, but these were all biplanes, and the condensers and collector tank for the condensed water were all mounted in the upper wing. In the Type 224 the collector tanks were in the undercarriage fairings, and, as the condensed water was nearly at boiling point, it was liable to turn to steam under any slight change of pressure; this frequently occurred in the water pumps and would cause them to stop working.[2]
Performance
The Type 224 first flew on 19 February 1934, piloted by "Mutt" Summers.[3] Its performance was disappointing—the maximum speed was 228 miles per hour (367 km/h) and it took 9.5 minutes to climb to 15,000 ft (4,600 m), well below the predicted performance of a 245 miles per hour (394 km/h) speed and climb to 15,000 ft (4,600 m) in 6.6 minutes.[4]
Mitchell was already in discussions about a number of improvements to the Type 224—a new wing, tailplane, and engine arrangements—which would give it a top speed of 265 miles per hour (426 km/h). The Ministry decided that a new aircraft, rather than a modification of the Type 224, was called for. In 1933.[5]
Name
Supermarine had asked the Air Ministry for the name "Spitfire" to be reserved for the type.[5] It ended its career during the summer of 1937, when it was used as for target practice at Orford Ness, Suffolk.[6]
Specifications (Supermarine Type 224)
Data from Supermarine Aircraft since 1914.[7]
General characteristics
- Crew: 1
- Length: 29 ft 5+1⁄4 in (8.973 m)
- Wingspan: 45 ft 10 in (13.97 m)
- Height: 11 ft 11 in (3.63 m)
- Wing area: 295 sq ft (27.4 m2)
- Airfoil: root: NACA 0018; tip: RAF 34[8]
- Empty weight: 3,422 lb (1,552 kg)
- Gross weight: 4,743 lb (2,151 kg)
- Powerplant: 1 × Rolls-Royce Goshawk II V-12 evaporative/steam cooled piston engine, 600 hp (450 kW)
- Propellers: 2-bladed fixed-pitch propeller
Performance
- Maximum speed: 228 mph (367 km/h, 198 kn) at 15,000 ft (4,600 m)
- Service ceiling: 38,800 ft (11,800 m) Absolute ceiling
- Time to altitude: 15,000 ft (4,600 m) in 9 minutes 30 seconds
Armament
- Guns: 4× 0.303 in (7.7 mm) Vickers Mk IV machine-guns
See also
 | This section needs additional citations for verification. (March 2024) |
Aircraft of comparable role, configuration, and era
- Arado Ar 80
- Blackburn F3
- Bristol Type 123
- Bristol Type 133
- Dewoitine D.500
- Gloster Gladiator
- Gloster SS.19
- Hawker P.V.3
- Westland F.7/30
References
- ^ Halley & Sturtivant 1996, p. 88.
- ^ Price 2002, pp. 12–13.
- ^ Andrews & Morgan 1981, p. 206.
- ^ Andrews & Morgan 1981, p. 207.
- ^ a b Buttler 2004, p. 10.
- ^ Price 2002, p. 14.
- ^ Andrews & Morgan 1981, p. 209.
- ^ Lednicer, David (28 September 2023). "The Incomplete Guide to Airfoil Usage". UIUC Applied Aerodynamics Group. Archived from the original on 7 February 2024. Retrieved 29 March 2024.
Sources
- Andrews, C. F. & Morgan, Eric B. (1981). Supermarine Aircraft since 1914. London: Putnam. ISBN 978-0-370-10018-0.
- Buttler, Tony (2004). Fighters & Bombers, 1935–1950. British Secret Projects. Vol. III. Hinckley, UK: Midlands Publishing. ISBN 978-1-85780-179-8.
- Halley, James J.; Sturtivant, Ray (1996). "Operational Requirements". Aeromilitaria. No. 4. Air Britain. pp. 87–106. ISSN 0262-8791.
- Price, Alfred (2002). The Spitfire Story (2nd ed.). Silverdale: Enderby. ISBN 0-85368-861-3.
External links
- Images of the Type 224 from Destination's Journey (Archived from the original on 29 March 2024).