Scottish Aviation Twin Pioneer

Twin Pioneer
275px
Air Atlantique Classic Flight Scottish Aviation Twin Pioneer
Type	Transport
Manufacturer	Scottish Aviation
Maiden flight	25 June 1955
Introduced	1956
Retired	1968
Primary users	Royal Air Force Malaysia Nepal
Number built	87
Developed from	Scottish Aviation Pioneer

The Scottish Aviation Twin Pioneer was a British STOL transport aircraft built by Scottish Aviation Limited at Prestwick Airport, Scotland, during the 1950s. It was designed with both civil and military operators in mind. It was conceived as a twin-engined version of the Pioneer light transport.

Design and development

Powered by two Alvis Leonides 531 radial engines, it was a high-wing cabin monoplane with a triple fin and rudder assembly and fixed tailwheel undercarriage. The prototype Twin Pioneer, registered G-ANTP, first flew at Prestwick Airport on 25 June 1955. Flight trials proved that the aircraft had a very short landing run and the aircraft was displayed at the 1955 Society of British Aircraft Constructors Show at Farnborough.

Three pre-production aircraft were built for trials, and sales and demonstrations.

In 1958 the 33rd aircraft was used as a prototype for the Series 2 with Pratt & Whitney Wasp R-1340 radial engines which had been ordered by Philippine Air Lines. A Series 3 aircraft was also developed to use the improved Alvis Leonides 531 radial engine.

Operational history

The military version could carry external stores such as bombs under stub wings. One aircraft became the first aircraft for the newly formed Royal Malaysian Air Force. The Royal Air Force ordered 39 aircraft, which were built between 1958 and 1959, for use in Aden and the Far East. It was used extensively by British forces in the Malayan Emergency and the later confrontation in Borneo. In August 1959 No. 78 Squadron RAF at Khormaksar received some Twin Pioneers to supplement its single engine Pioneers. The Twin Pioneers were engaged in moving troops and supplies around the wilderness and on occasions, lending support to the Sultan of Oman. A series of double engine failures caused problems with the squadron losing two aircraft on the same day. Unsuitable soft and hard landing strips were also causes of failures during landings.

Other squadrons that operated the Twin Pioneers were No. 152 Squadron RAF based at Muharraq in Bahrain: No. 21 Squadron RAF, which reformed with the type at Benson in May 1959. The squadron then moved to Kenya and in June 1965 to Aden. No. 152 operated around the Persian Gulf and in 1959, No. 209 Squadron RAF based at Seletar began to receive Twin Pioneers. These operated in Borneo and Malaya. Finally the last of Twin Pioneer operators was No. 230 in the UK. These operated the type in interesting camouflage colour scheme. The SRCU 9 Short Range Conversion Unit) at RAF Odiham also flew three Twin Pioneers for aircrew training.

Although mainly used in military operations, the Twin Pioneer was also successful as a commercial transport. Some of the first sales were as survey aircraft, to Rio Tinto Finance and Exploration Limited, and the Austrian and Swiss government survey departments.

Variants

• Twin Pioneer : Prototype aircraft with Alvis Leonides 503 radial engines, one built.
• Twin Pioneer Series 1 : Production aircraft with Alvis Leonides 514 radial engines.
  • Twin Pioneer CC.Mk 1 : Military version of the Series 1 for the Royal Air Force, 32 built.
  • Twin Pioneer CC.Mk 2 : Military version of the Series 1 for the Royal Air Force, 7 built.
• Twin Pioneer Series 2 : Production aircraft with Pratt & Whitney R-1340 radial engines.
• Twin Pioneer Series 3 : Production aircraft with Alvis Leonides 531 radial engines.

Operators

Civil operators

• Australia
• Austria
• Canada
• Dutch East Indies
• Ecuador
• Iceland
• Indonesia
• Iran
• Kuwait
• Laos
• Malaysia
• Mexico
• Nepal
• Nigeria
• North Borneo
• Norway
• Philippines
• Sierra Leone
• Switzerland
• United Kingdom
• United States

Military operators

Template:MYS

• Royal Malaysian Air Force

Template:UK

• Royal Air Force
  • No. 21 Squadron RAF
  • No. 78 Squadron RAF
  • No. 152 Squadron RAF
  • No. 209 Squadron RAF
  • No. 225 Squadron RAF
  • No. 230 Squadron RAF
• Empire Test Pilots' School

Specifications (Twin Pioneer CC.Mk 1)

General characteristics

• Crew: Two (pilot and co-pilot)
• Capacity: up to 13 troops or 2,000 lb (907 kg) of cargo
• Length: 45 ft 3 in (13.79 m)
• Wingspan: 76 ft 6 in (23.32 m)
• Height: 12 ft 3 in (3.73 m)
• Wing area: 670 ft² (62 m²)
• Empty weight: 10,200 lb (4,627 kg)
• Max takeoff weight: 14,600 lb (6,622 kg)
• Powerplant: 2× Alvis Leonides 531 , 640 hp (564 kW) each

Performance

• Maximum speed: 143 knots (165 mph, 266 km/h)
• Range: 695 nm (791 mi, 1,287 km)
• Service ceiling: 20,000 ft (6,098 m)
• Rate of climb: 1,250 ft/min (381 m/min)

See also

Related development
Scottish Aviation Pioneer

Related lists

• List of aircraft of the RAF

References

• Donald, David, ed. The Encyclopedia of World Aircraft. London: Aerospace Publishing, 1997. ISBN 1-85605-375-X.
• Thetford, Owen. Aircraft of the Royal Air Force 1918-57, 1st edition. London: Putnam, 1957.

External links

• RAF Museum entry

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Scottish Aviation Twin Pioneer".