Auster AOP.9

https://en.wikipedia.org/wiki/Auster_AOP.9

The Auster AOP.9 was a British military air observation aircraft ("Air
Observation Post") produced by Auster Aircraft Limited to replace the Auster
AOP.6.

The Auster AOP.9 was designed as a successor to the Auster AOP.6. Like its
predecessor, it was a braced high-wing single engined monoplane with a fixed
tailwheel undercarriage. Although having the same general appearance, the AOP.9
was a new design, with larger wing area and a more powerful engine. The wing and
tail were metal-skinned, but the fuselage and ailerons were fabric-covered. The
fin and rudder assembly were more angular in the new aircraft with a noticeable
dorsal fillet. A combination of the more powerful 180 hp (134 kW) Blackburn
Cirrus Bombardier engine, larger wings and large flaps gave it an improved
take-off and landing performance compared with the AOP.6. It could operate from
ploughed fields and muddy surfaces using low pressure tyres and strengthened
undercarriage.

The cabin held three seats, pilot and passenger side-by-side and the observer
behind, facing either forwards or rearwards. The aircraft was also designed to
be convertible into a two-seat light transport with an interchangeable rear
floor. In this configuration the observer sat alongside the pilot.


Role
military observation aircraft

Manufacturer
Auster Aircraft Limited

First flight
19 March 1954

Introduction
1955

Primary users
Army Air Corps
Royal Air Force, Indian Air Force

Number built
182

Deliveries started to the Royal Air Force in February 1955, replacing AOP.6s in
the regular AOP squadrons, the auxiliary squadrons disbanding in March 1957
before receiving AOP.9s. Until the formation of the Army Air Corps (AAC) in
September 1957, Army personnel flew RAF aircraft based in RAF squadrons.

The aircraft were in action with No. 656 Squadron from September 1955, flying an
average of 1,200 sorties per month. By the end of Operation Firedog in Malaya on
31 July 1960, 656 Squadron's AOP.6 and AOP.9s had carried out 143,000 sorties.

The AOP.9s were involved in several of Britain's other end of Empire conflicts;
653 Squadron AAC used them in Aden in the early 1960s, flying from Falaise,
Little Aden. They stayed in service until 1966 and were the last fixed wing AOP
aircraft used by the AAC, though their light transport role was taken over by
Beavers.

Specifications (AOP.9)

General characteristics
Crew: 2/3
Length: 23 ft 8½ in (7.24 m)
Wingspan: 36 ft 5 in (11.10 m)
Height: 8 ft 11 in (2.72 m)
Wing area: 197.6 ft² (18.36 m²)
Empty weight: 1,460 lb (663 kg)
Loaded weight: 2,100 (953 kg)
Max. takeoff weight: 2,330 lb (1,057 kg)
Powerplant: 1 × Blackburn Cirrus Bombardier 203 4-cylinder inverted inline
piston, 173 hp (129 kw)

Performance
Maximum speed: 127 mph (204 km/h)
Cruise speed: 110 mph (178 km/h)
Range: 242 miles (389 km)
Service ceiling: 18,500 ft (5640 m)
Rate of climb: 920 ft/min (280 m/min)
Wing loading: 10.4 lb/ft2 (50.4 kg/m2)
Power/mass: 11.9 lb/hp (7.25 kg/kW)





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