The Apollo (AW 55) 




The Apollo was the first axial flow turboprop airliner in the world, being built to the Ministry Specification, Brabazon 2B.


Two prototypes were made, but no production orders ensued, the rival in this field being the slightly larger Viscount with Dart engines.



The first flight was on 10th April 1949 and a limited Certificate of Airworthiness clearance was obtained in December 1950, followed by its use as a vehicle for the Decca Navigation System at Boscombe Down, before being dismantled in 1954.


Power Plant:  

4 Armstrong Siddeley Mamba Turboprops providing 1,000 static shp. plus 320 lb. jet thrust.


30,800 lb. Empty.

47,000 lb. A.U.W.











Max. Speed                                  345 mph.

Normal Cruise at 25,000 ft.         276 mph.

Rate of Climb (4 engines)           1,500 ft. / min.

Still Air Range at 25,000 ft.          1,350 miles.




Flight Crew of 3 plus 1 or 2 stewards.

24 to 31 Passengers.



Features of design were the very small cross-section of the engine nacelles, as suited to the Mamba, the pressurised cabin, the advanced form of wing construction, thermal anti-icing and Fowler flaps.


An interesting aspect of the preparatory programme was the water tank tests for the pressurised hull, probably the first full scale test of this nature in the world, which subjected the whole of the fuselage to the pressure differential encountered at altitudes up to 25,000 ft.