Goodyear Type AD
Non-rigid airship construction continued with the revolutionary Goodyear Type AD "Pilgrim", which first flew on June 3, 1925 with a capacity of 123,000 cu ft. With this airship a new system of internal rigging was used for the first time which enabled the control car to be rigged flush with the underside of the envelope, thereby reducing the aerodynamic drag and the overall height of the ship. The envelope volume was 50,000 cu ft and the ship was powered by a 60 h.p. Lawrence engine which gave a speed of 50 m.p.h. at full power. The interior of the enclosed cabin was luxuriously appointed with blue mohair velour upholstery and mahogany-finished veneer below the window lines. Seating was for a pilot and two passengers, with a rear cockpit for an engine mechanic.
The first flight was made with the envelope inflated with hydrogen, but a month later it was re-inflated with helium and flew for the first time with this gas on July 17, 1925. Since then all Goodyear airships have employed helium as the lifting agent. "Pilgrim", registered NC-9A in 1927, remained in service until December, 1931, completing 2,880 hours and carrying 5,355 people. before honourable retirement. It is now preserved by the Smithsonian Institution, Washington, D.C. Its design formed the basis of all subsequent non-rigid airships built by Goodyear and was the prototype for all modern pressure airships.
Goodyear Type AD (Pilgrim) 1925
Engine: 1 x 60 hp Lawrence air-cooled radial.
Length: 105ft 6in.
Maximum diameter: 31 ft.
Volume: 50,068 cu ft (before stretch).
Maximum Speed: 50 m.p.h.
Cruising Speed: 40 m.p.h.
Range: 330 miles at full power, 525 miles at half power.
Endurance: 61 hours at full power, 13 hours at half power.
Fuel: 32 Imp.Gal.
Useful load: 921 lb