Supermarine Scapa

The Supermarine Scapa was a British general reconnaissance flying boat built by Supermarine that was used by the Royal Air Force between 1935 and 1939. It was developed from the Southampton and formed the basis of the Supermarine Stranraer.

Scapa
A Supermarine Scapa at the MAEE at Felixstowe, in 1933
General information
Type	Reconnaissance flying boat,
National origin	United Kingdom
Manufacturer	Supermarine Aviation Works (Vickers), Ltd.
Designer	R.J. Mitchell
Primary user	Royal Air Force
Number built	15
History
Introduction date	1935
First flight	1932
Retired	1939
Developed from	Supermarine Southampton
Developed into	Supermarine Stranraer

Development

After experimenting with a three-engine design of flying boat, the Nanok, Supermarine's chief designer R. J. Mitchell decided that the hydrodynamic design developed in the twin-engined Supermarine Southampton, would be suitable for the next aircraft.

A prototype, designated the Southampton IV, was built. It had a hull that exceeded expectations in tests. An Air Ministry Specification was received in November 1931. The test pilot Joseph "Mutt" Summers took first flew the prototype on 8 July, 1932, by which time the name of the type had been changed to Scapa.

After 15 Scapas were built, production was changed to a more powerful development, the Supermarine Stranraer.

Design

Cut-away illustration of the Scarpa from Flight magazine (June 1935)

The Scapa's hull was an all-metal structure, while the wing and tail surfaces had metal structure with fabric covering. The two Rolls-Royce Kestrel V12 engines were mounted in nacelles underslung from the upper wing, and there were two fins, each placed at the mid semi-span of the tailplane. Similar to the Southampton, there were three gun positions: one in the nose, and two staggered in the rear fuselage. Each provided with a single .303 British (7.7 mm) caliber Lewis Mk.I machine guns.

Operators

United Kingdom

• Royal Air Force
  • No. 202 Squadron RAF
  • No. 204 Squadron RAF
  • No. 228 Squadron RAF
  • No. 240 Squadron RAF

Specifications (Scapa)

Supermarine Scapa 3-view drawing from NACA-AC-203

Data from Supermarine Aircraft Since 1914

General characteristics

• Crew: 5
• Length: 53 ft 0 in (16.15 m) on beaching gear
• Wingspan: 75 ft 0 in (22.86 m)
• Height: 21 ft 0 in (6.40 m) on beaching gear
• Wing area: 1,300 sq ft (120 m²)
• Empty weight: 10,030 lb (4,550 kg)
• Gross weight: 16,080 lb (7,294 kg)
• Powerplant: 2 × Rolls-Royce Kestrel IIIMS V-12 liquid-cooled piston engines, 525 hp (391 kW) each
• Propellers: 2-bladed wooden fixed-pitch propellers

Performance

• Maximum speed: 142 mph (229 km/h, 123 kn) at 3,280 ft (1,000 m)
• Cruise speed: 100 mph (160 km/h, 87 kn) at 5,000 ft (1,524 m)
• Alighting speed: 64 mph (56 kn; 103 km/h)
• Range: 1,000 mi (1,600 km, 870 nmi) with 2,650 lb (1,202 kg) military load
• Service ceiling: 15,500 ft (4,700 m)
• Rate of climb: 625 ft/min (3.18 m/s)
• Time to altitude: 9,840 ft (2,999 m) in 20 minutes
• Wing loading: 12.3 lb/sq ft (60 kg/m²)
• Power/mass: 0.065 hp/lb (0.107 kW/kg)

Armament

• Guns: 3 × 0.303 in (7.7 mm) Lewis guns, one in bow and two amidships
• Bombs: 1,000 lb (454 kg) bombload under the wings

See also

Related development

• Supermarine Southampton
• Supermarine Stranraer

Aircraft of comparable role, configuration, and era

• Hall PH
• Hiro H1H
• Hiro H2H
• Naval Aircraft Factory PN

Related lists

• List of aircraft of the Royal Air Force
• List of flying boats and floatplanes

Sources

• Andrews, C. F.; Morgan, Eric B. (1981). Supermarine Aircraft since 1914. London: Putnam. ISBN 978-03701-0-018-0.

Further reading

• Hillman, Jo·; Higgs, Colin (2020). Supermarine Southampton: The Flying Boat that Made R. J. Mitchell. Barnsley, UK: Pen & Sword Books Limited. ISBN 978-15267-8-497-1.
• Shelton, John (2008). Schneider Trophy to Spitfire: The Design Career of R. J. Mitchell. Sparkford: Hayes Publishing. ISBN 978-1-84425-530-6.