Talk:Supermarine Seagull (1948)

Supermarine Seagull.

This was an amphibious aircraft, built by Supermarine in the early 1950's. Two prototypes were built, PA143 and PA147. A third airframe PA152 was only partially finished.

Description

They were intended as a Walrus/Sea Otter replacement for air/sea rescue. The aircraft had a pylon mounted wing, with a single Rolls-Royce Griffon engine. The radiator was mounted in the front of the pylon. The engine drove a 6-blade contra-rotating propeller, which had only a few inches clearance fropm the top of the fuselage. The propeller was just behind the cockpit. The Seagull, which had a low waistline, had a hatch on top of the fuselage, this was to enable easy rescue of downed aircrew from the sea.

PA143 had twin fins and rudders, and later modifies with PA147 to have triple fins.

The Seagull was fitted with a variable-incidence wing that could be varied in flight mounted on top of a pylin, powered by a 7.5 kVA 3-phase alternator, (with a back-up 2.5 kVA unit). This enabled the airplane to fly as slow as 35 mph, with a declared top speed of 270 mph, although the pilots said it would do 320 mph.

Personal comments (Davefoulds)

I was stationed at the Marine Aircraft Experimental Establishment, RAF Felixstowe, in late 1951 and early 1952. We had PA147 in the hangar. It had a small hole in the starboard wheelwell, caused by a Methyl Bromide fire extinguisher that exploded due to a small electrical fire near to the pressurised extinguisher. So I never saw it fly, but I saw photos of it on take-off, where it disappeared in a cloud of spray and then emerged flying. It never went into service.

Specifications (Estimated with Griffin 57)

• Powerplant - one 1815 hp Rolls-Royce Griffin 29
• Crew - Three
• Span - 52 ft 10½ in (16m)

• Wing folded width - 23 ft 6 in (7.17m)
• Length - 44 ft 1½ in (13.46m)
• Height - 15 ft 10½ in (4.84m)
• Wing Area - 432 sq ft (40.13 sq m)

• Empty Weight - 10510 lb (4770 kg)
• Loaded weight - 14500 lb (6583 kg)

• Max Speed - 260 mph (418 km/h)at 11800 ft (3599 m)
• Range - 875 miles (1408 km) at 131 mph (211km/h)
• Max rate of climb - 1430 ft/min (436 m/min) at 7000 ft (2133 m)

Reference

"Supermaine Aircraft since 1914" by Andrews & Morgan - published by Putham - ISBN 0-370-10018-2

powerplant description

The current(soon to be former) description of the powerplant in the specification section describes the engine as being inline. It is a Rolls Royce Griffon which is a V12 liquid cooled piston engine not an inline engine. I'm making this change now. DieselDude (talk) 19:22, 30 July 2012 (UTC)

I have edited it further to remove the description which does not normally appear in aircraft specification sections. There is an article (Inline engine (aviation)) which is very poor and eludes that V-engines come under this heading, an inline engine to me is one set of cylinders in a row (per de Havilland Gipsy Six). Nimbus (Cumulus nimbus floats by) 21:24, 30 July 2012 (UTC)

Actually an 'inline' engine is so-called in contrast to a radial. All the V-12s such as the Merlin, Griffon, DB 601 series, Allison, etc., were referred to as 'inline' engines at the time, at least this 'side of the pond'.

With the disappearance of the rotary as an engine type post World War I, the only remaining relevant difference between configurations for high powered aircraft was inline or radial.

... so whereas a Ranger or Gypsy Major was also an 'inline', a Jaguar was a radial. V-12s, H-24s, V-6s were also 'inline' engines - because they weren't radials. — Preceding unsigned comment added by 80.7.147.13 (talk) 08:41, 28 August 2012 (UTC)