P.50 Prince, P.54 Survey Prince and P.57 Sea Prince:
The Percival Aircraft Company was established in 1932 by the Australian designer Edgar Percival to build his Gull series of single-engine tourers. Major expansion occurred with development of the four-seat Vega Gull, and in 1936 the company restructured and moved from its original works at Gravesend to larger premises at Luton. Wartime activities included the manufacture of over 650 Proctors, a developed version of the Vega Gull designed to fulfil an Air Ministry requirement for a radio trainer and communications aircraft, and 1,355 Airspeed Oxfords. Like many other companies, Percival turned to the civil market after the war, concentrating initially on a civilianised version of the Proctor. On 9 May 1947, Percival flew the prototype of a 5-8 seat, high wing airliner, known as the P.48 Merganser. This was developed and put into production as the Prince, but few commercial sales were forthcoming. The largest customer was the Fleet Air Arm, which acquired 48 Sea Princes for observer training and communications. The type remained in service until 1978, when it was replaced by the Handley Page Jetstream.
First flight: 13 May 48 (c/n P50/01, G-ALCM)
Production: 74, at Luton, UK
First delivery: 31 Jan 50, to Hunting Aerosurveys (c/n P50/08, G-ALRY)
Last delivery: 3 Sep 53, to the Fleet Air Arm (c/n PAC/57/74, WJ350)
Variants: P.50 Prince 1 - initial version powered by 2 Alvis Leonides 501/4 radials, with seating for up to 12 passengers (3 built);
P.50 Prince 2 - Prince 1 with detail changes and increased take-off weight (5 built);
P.50 Prince 3 - Prince 2 powered by Leonides 502/4s (12 built);
P.54 Survey Prince - Prince 2 optimised for aerial photography and observation, with lengthened transparent nose and provision for cameras (6 built);
P.57 Sea Prince C.1 - Prince 3 optimised for use as an 8-seat naval communications aircraft (3 built; first flight 24 Mar 50);
P.57 Sea Prince T.1 - Prince 3 optimised as observer training with radar nose and other design changes (41 built; first flight 28 Jun 51);
P.57 Sea Prince C.2 - transport version of Sea Prince T.1 (4 built).
P.66 Pembroke:
Following the Fleet Air Arm’s acquisition of the Prince, the Royal Air Force (RAF) began to show an interest in adopting the type as a communications aircraft. The load carrying abilities of the Prince were insufficient for the RAF’s needs, so Percival re-engineered the aircraft with an extended wing span, necessary to generate the additional lift required to carry heavier loads. The RAF placed an initial order for 42 of the new type, known as the Pembroke, on 5 June 1951. It went on to place three further follow-on orders, for an eventual total of 57. Export orders were received from Belgium, Denmark, Finland, Sweden and West Germany, encouraging Percival to offer a version for the commercial market, which it called the President. As with the Prince, a survey version was offered and this was used in the photo-reconnaissance role by the RAF during the Malaya Emergency and, latterly, on flights along the West Berlin Air Corridor. Routine inspections of RAF aircraft in the late-1960s revealed fatigue cracks, and this led to the re-sparring of 14 aircraft by the British Aircraft Corporation at Weybridge 1970-71. Most other operators retired their Pembrokes at around this time, but the re-sparred RAF aircraft remained in service until 1988. Four-digit construction numbers were introduced when Hunting Percival was re-named Hunting Aircraft, in 1957.
First flight: 21 Nov 52 (c/n 1, WV698)
Production: 133, at Luton, UK
First delivery: 2 Aug 53, to the Royal Air Force (c/n 3, WV700)
Last delivery: 5 Mar 60, to the Sudanese Air Force (c/n 108 and 104, serials 11 and 12)
Variants: Pembroke C.1 - developed version of the Prince with seating for 12 passengers, powered by Alvis Leonides 127 radials (export aircraft were given specific marque numbers but were broadly similar to the C.1); President - Pembroke C.1 optimised for the civil market with longer engine nacelles for better single-engine performance; exported to the Sudanese Air Force as the Pembroke C.55).