Aero Spacelines started work in 1961 on the conversion of a Boeing B-377 Stratocruiser to an outsize cargo aircraft able to airlift large booster rocket stages being employed in the American space programme, for the transport of aircraft assemblies, oil drilling equipment, and any other items too large to be carried by any then existing aircraft.
Designed by Jack Conroy, the fuselage of ex-airline Boeing 377 N1024V was extended by 5.08m aft of the wing, and a new ‘bubble’ structure was added over the top of the fuselage to allow the loading of items up to 6.02m in diameter. Capable of carrying 34,000 lb of cargo, the resulting B-377PG Pregnant Guppy was flown for the first time on 19 September 1962, and was used from the summer of 1963, under contract to NASA, for the transport of space programme hardware. Aircraft was loaded by removing the tail section just aft of the wing trailing edge.
377PG “Pregnant Guppy”
Engines: 4 x Pratt-Whitney R-4360, 23500hp / 625kW
Wingspan: 43.05 m / 141 ft 3 in
Length: 38.71 m / 127 ft 0 in
Take-off weight: 60200 kg / 132719 lb
Empty weight: 41200 kg / 90831 lb
Payload: 13100kg / 28881 lb
Speed: 240 mph
All Aero 