Parnall Peto

Design and development

Two examples were designed and built by George Parnall and Company and were given serial numbers N181 and N182, the first prototype, N181 crashed at Gibraltar and was rebuilt as N255 before being lost with the submarine HMS M2 when her hangar flooded. The Peto was one of the most challenging design projects that the Parnall company undertook, because of the very small hangar in which the aircraft had to fit, mounted immediately in front of the submarine's conning tower.

Of mixed wood, fabric, aluminium and steel construction, it had unequal span, Warren-braced folding rectangular wings. The first aircraft, N181, was powered by a 128 hp Bristol Lucifer engine and had mahogany plywood "Consuta" type floats. Performance was generally satisfactory but following crash damage, improvements were made and the machine was rebuilt with new wings, metal floats and a 169 hp Armstrong Siddeley Mongoose engine. Tests both on the sea and in the air showed that designer, Harold Bolas, had met the requirements and it was officially judged to be exceptionally good.

The aircraft was launched using a compressed air catapult mounted on the forward casing of the submarine and recovered using a crane.

With the loss of M2, the Royal Navy abandoned submarine-launched aircraft, although most other navies also experimented with the concept in the interwar years.

Aircraft

The two aircraft built were:

N181

Prototype which was wrecked at Gibraltar on 11 February 1930 and rebuilt as N255 with improved floats and lost with HMS M2.

N182

Which crashed 29 June 1930 at Stokes Bay. It was acquired by F.C.H. Allen and prepared for civil use at Ford aerodrome in Sussex between 1933 and 1934. Issued with civilian Registration G-ACOJ but the project was abandoned.

Specifications

Data from Wixey, pp.159-160

General characteristics

Crew: two (pilot and observer)

Length: 22 ft 6 in (6.86 m)

Wingspan: 28 ft 5 in (8.66 m)

Height: 8 ft 11 in (2.72)

Wing area: 174 ft² (16.17 m²)

Empty weight: 1,300 lb (590 kg)

Loaded weight: 1,950 lb (885 kg)

Powerplant: 1 × Armstrong Siddeley Mongoose IIIC five-cylinder air-cooled radial engine with two bladed wooden propeller, 135 hp (101 kW)

Performance

Maximum speed: 113 mph (182 km/h) at sea level

Endurance: 2 hours

Service ceiling: 11,300 ft (3,477 m)

Rate of climb: 600 ft/min (3.05 m/s)