Airliner · Civil · United States
Boeing 377 Stratocruiser
- July 8, 1947
- First flight
- 1949
- Introduced
- 1978
- Retired
- 56
- Units built
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The Boeing 377 Stratocruiser, the civil derivative of the C-97 and ultimately of the B-29 bomber, first flew on 8 July 1947 and entered service with Pan American on 1 April 1949. With its double-deck fuselage and lower-deck lounge it embodied postwar transoceanic luxury, though only 56 were built.
History
Boeing derived the 377 Stratocruiser from the C-97 Stratofreighter military transport, itself descended from the B-29 bomber. The result was unmistakable: a double-lobe, double-deck fuselage powered by four Pratt & Whitney R-4360 Wasp Major engines. The prototype flew on 8 July 1947 and Pan American put the type into service on 1 April 1949.
The Stratocruiser competed on the most prestigious routes with a luxury that became legendary: a lower-deck lounge seating 14, sleeping berths and a roomy cabin. That opulence rested on fragile economics, though: the R-4360s suffered propeller failures, operating costs ran high, and production closed at just 56 aircraft. Airlines phased it out through the fifties, and the type is regarded as retired in 1963.
Its silhouette nevertheless enjoyed an unlikely afterlife. Several airframes were converted by Aero Spacelines into the outsized-cargo Guppy family, used to carry rocket stages and large aircraft assemblies, so the Stratocruiser line kept flying in the service of the space age long after it vanished from passenger routes.
Variants
| 377-10-19 | Aero Spacelines 377PG Pregnant Guppy | Aero Spacelines 377SG Super Guppy | Aero Spacelines 377MG Mini Guppy | Aero Spacelines 101 Mini Guppy Turbine | 377-1 | 377-10-26 | 377-10-26S Super Stratocruiser | 377-10-27 | 377-10-28 | 377-10-29 | 377-10-30 | 377-10-32 | 377-10-34 | 377-10-40 | 377-11 | 377-17-39 | 377-212 | 377-28-26 | 377-6 | 377F | 377M Anak | Aero Spacelines 377SGT Super Guppy Turbine | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| First flight | July 8, 1947 | September 19, 1962 | August 31, 1965 | May 24, 1967 | March 13, 1970 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Aircraft type | Long-haul airliner | Outsize cargo transport | Outsize cargo transport | Outsize cargo transport | Outsize cargo transport | Long-haul airliner (proposal) | Long-haul airliner | Long-haul airliner | Long-haul airliner (not built) | Long-haul airliner | Long-haul airliner | Long-haul airliner | Long-haul airliner | Long-haul airliner | High-capacity airliner (proposal) | Long-haul airliner (proposal) | Long-haul airliner (proposal) | High-capacity airliner (proposal) | Long-haul airliner (proposal) | Long-haul airliner (proposal) | Cargo aircraft | Military cargo transport | Outsize cargo transport |
| Powerplant | 4 × Pratt & Whitney R-4360-B6 Wasp Major radial piston engines, 2,610 kW each. | 4 × Pratt & Whitney R-4360-B6 Wasp Major radial piston engines, 2,610 kW each, with Aerojet-General solid-fuel assisted take-off rockets. | 4 × Pratt & Whitney T34-P-7WA turboprops, 5,145 kW each, taken from the YC-97J. | 4 × Pratt & Whitney R-4360-B6 Wasp Major radial piston engines, 2,610 kW each. | 4 × Pratt & Whitney T34-PWA turboprops, 4,300 kW each. | 4 × Wright R-3350 Duplex-Cyclone radial piston engines. | 4 × Pratt & Whitney R-4360-B6 Wasp Major 28-cylinder four-row air-cooled supercharged radial piston engines, 2,610 kW each (3,500 hp on take-off with water injection), driving four-blade constant-speed fully feathering propellers. | 4 × Pratt & Whitney R-4360 Wasp Major radial piston engines, re-engined with a more powerful version than the standard 377-10-26. | 4 × Pratt & Whitney R-4360 Wasp Major radial piston engines, as standard for the type. | 4 × Pratt & Whitney R-4360-B6 Wasp Major radial piston engines, 2,610 kW each. | 4 × Pratt & Whitney R-4360-B6 Wasp Major radial piston engines, 2,610 kW each. | 4 × Pratt & Whitney R-4360-B6 Wasp Major radial piston engines, 2,610 kW each. | 4 × Pratt & Whitney R-4360-B6 Wasp Major radial piston engines, 2,610 kW each. | 4 × Pratt & Whitney R-4360-B6 Wasp Major radial piston engines, 2,610 kW each. | 4 × Pratt & Whitney R-4360 Wasp Major radial piston engines, as standard for the type. | 4 × Wright XA-395 turbine engines, a powerplant study never built. | 4 × Allison XT40-A-6 turboprop engines. | 4 × Pratt & Whitney R-4360 Wasp Major radial piston engines, as standard for the type. | Six piston engines: the four Pratt & Whitney R-4360 Wasp Majors of the production aircraft plus two Wright R-1820 Cyclones added outboard. | 4 × supercharged Allison V-3420 piston engines, a double-bank V layout. | 4 × Pratt & Whitney R-4360-B6 Wasp Major radial piston engines, 2,610 kW each. | 4 × Pratt & Whitney R-4360-59 Wasp Major radial piston engines. | 4 × Allison 501-D22C turboprops, 3,490 kW each. |
| Powerplant | 4 × Pratt & Whitney R-4360-B6 Wasp Major | 4 × Pratt & Whitney R-4360-B6 Wasp Major | 4 × Pratt & Whitney T34-P-7WA | 4 × Pratt & Whitney R-4360-B6 Wasp Major | 4 × Pratt & Whitney T34-PWA | 4 × Wright R-3350 Duplex-Cyclone | 4 × Pratt & Whitney R-4360-B6 Wasp Major | 4 × Pratt & Whitney R-4360 Wasp Major | 4 × piston | 4 × Pratt & Whitney R-4360-B6 Wasp Major | 4 × Pratt & Whitney R-4360-B6 Wasp Major | 4 × Pratt & Whitney R-4360-B6 Wasp Major | 4 × Pratt & Whitney R-4360-B6 Wasp Major | 4 × Pratt & Whitney R-4360-B6 Wasp Major | 4 × piston | 4 × Wright XA-395 | 4 × Allison XT40-A-6 | 4 × piston | 6 × 4 × Pratt & Whitney R-4360 Wasp Major + 2 × Wright R-1820 Cyclone | 4 × Allison V-3420 | 4 × Pratt & Whitney R-4360-B6 Wasp Major | 4 × Pratt & Whitney R-4360-59 | 4 × Allison 501-D22C |
| Power per engine | 3,500 hp | 3,500 hp | 6,900 hp Best value in this row | 3,500 hp | 5,766 hp | — | 3,500 hp | — | — | 3,500 hp | 3,500 hp | 3,500 hp | 3,500 hp | 3,500 hp | — | — | — | — | — | — | 3,500 hp | — | 4,680 hp |
| Length | 33.6 m | 38.7 m | 43.8 m | 40.5 m | — | — | 33.6 m | 33.6 m | — | 33.6 m | 33.6 m | 33.6 m | 33.6 m | 33.6 m | — | — | — | — | — | — | 33.6 m | 33.6 m | 43.8 m Best value in this row |
| Wingspan | 43.1 m | 43.1 m | 47.6 m Best value in this row | 47.6 m Best value in this row | — | — | 43.1 m | 43.1 m | — | 43.1 m | 43.1 m | 43.1 m | 43.1 m | 43.1 m | — | — | — | — | — | — | 43.1 m | 43.1 m | 47.6 m Best value in this row |
| Height | 11.7 m | 11.7 m | 14.8 m Best value in this row | 11.7 m | — | — | 11.7 m | 11.7 m | — | 11.7 m | 11.7 m | 11.7 m | 11.7 m | 11.7 m | — | — | — | — | — | — | — | — | 14.8 m Best value in this row |
| Wing area | — | 164 m² | 183 m² Best value in this row | — | — | — | 164 m² | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Empty weight | — | 41,277 kg | 45,359 kg | 41,000 kg | — | — | 37,875 kg | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 37,874 kg Best value in this row | 46,040 kg |
| MTOW | — | 60,328 kg | 77,111 kg | 64,770 kg | — | — | 67,132 kg | — | — | — | — | — | — | — | — | — | 69,000 kg | — | — | — | — | 79,380 kg Best value in this row | 77,111 kg |
| Top speed | — | 590 km/h | — | — | — | — | 604 km/h Best value in this row | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 604 km/h Best value in this row | 460 km/h |
| Max speed altitude | — | — | — | — | — | — | 7,620 m | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Cruise speed | — | 361 km/h | 502 km/h | 386 km/h | — | — | 547 km/h Best value in this row | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 547 km/h Best value in this row | 410 km/h |
| Cruise altitude | — | — | — | — | — | — | 7,620 m | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Service ceiling | — | — | 7,620 m | 6,100 m | — | — | 9,800 m Best value in this row | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 9,800 m Best value in this row | 7,600 m |
| Initial climb rate | — | — | — | — | — | — | 5.6 m/s | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Range | — | — | 3,211 km | — | — | — | 6,800 km Best value in this row | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 6,760 km | 3,211 km |
| Ferry range | — | — | — | — | — | — | 7,360 km | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
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| Range conditions | — | Short-stage aircraft flown inside the United States between factories and NASA centres; normal operating speed cut by the deep fuselage. | About 3,211 km, sized for the runs between factories and launch sites. | Lower ceiling and speed than the airliner it came from; flown on short outsize-cargo stages. | — | — | Around 6,800 km with a normal payload, enough for Pan American's transatlantic and Pacific stages; with maximum fuel, ferry figures of up to 7,360 km are quoted. | Greater fuel capacity than the 377-10-26 to fly Pan American's transatlantic stages non-stop. | — | — | — | — | — | — | — | — | — | — | — | — | — | About 6,760 km, as on the civil aircraft it came from, with no in-flight refuelling. | About 3,211 km, enough for the European legs between the Airbus plants and Toulouse. |
| Armament | None | None | None | None | None | None | None | None | None | None | None | None | None | None | None | None | None | None | None | None | None | None | None |
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| Payload | — | 15,422 kg | — | 15,000 kg | — | — | 11,400 kg | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 24,721 kg Best value in this row |
| Cargo capacity | Development prototype; one built, later brought up to 377-10-26 standard and sold to Pan American. | Conversion of a 377-10-26 with an enlarged upper deck and lengthened fuselage to carry Saturn rocket stages; hold of about 826 m³ and a payload of some 15,422 kg. | Deep-section fuselage built on parts of a YC-97J and a 377-10-26; the only aircraft able to carry a complete Saturn V third stage. | Conversion of a 377-10-26 with a widened cabin, stretched wing and hinged tail for end loading; hold about 22 m long by 5.5 m wide and some 15,000 kg of payload. | Mini Guppy derivative with a swinging nose for front loading and turboprop power. | Alternative-powerplant study; not built. | Pressurised double-deck airliner: typical layouts of 63 to 84 seats and up to 100 on the main deck, plus a 14-seat lower-deck lounge reached by a spiral staircase; night layouts offered 28 berths and five seats. Useful load about 11,400 kg of passengers, baggage and mail. | Ten Pan American aircraft refitted for transatlantic service. | Version intended for Transcontinental & Western Air; the order was never fulfilled. | Four aircraft ordered by Scandinavian Airlines System and taken over by BOAC after the cancellation, with a de luxe interior. | Eight aircraft for American Overseas Airlines, with circular main-cabin windows and rectangular lower-deck windows. | Ten aircraft for Northwest Orient Airlines, with all-rectangular windows. | Six aircraft for the British Overseas Airways Corporation, with all-circular windows. | Seven aircraft for United Air Lines, with rectangular main-cabin windows and circular lower-deck windows. | Proposal for domestic routes with high-density seating; not built. | Alternative-powerplant study; not built. | Stretched, turboprop-powered proposal for Cubana de Aviación; not built. | Proposed twin-deck all-economy cabin; not built. | Six-engined proposal for Pan American World Airways; not built. | Alternative-powerplant study; not built. | Freighter conversion of passenger aircraft, with the cabin stripped of seats. | Five aircraft bought from Pan American and rebuilt by Israel Aircraft Industries for the Israeli Air Force: C-97 tail, clamshell doors and a strengthened floor for cargo, paratroop drops and troop transport. | Definitive Guppy, with a cleaner fuselage and hinged nose: hold about 33 m long by 7.62 m wide and high, for some 24,721 kg. Four built, used by Airbus to move aircraft sections and later by NASA. |
| Crew | 4 | 3 Best value in this row | 4 | 4 | — | — | 4 | 4 | — | 4 | 4 | 4 | 4 | 4 | — | — | — | — | — | — | — | 4 | — |
| Passengers | — | — | — | — | — | — | 100 | — | — | — | — | — | — | — | 105 | — | 137 Best value in this row | — | — | — | — | — | — |
| Units built | 1 | 1 | 1 | 1 | 2 | 0 | 21 Best value in this row | 10 | 0 | 4 | 8 | 10 | 6 | 7 | 0 | 0 | 0 | 0 | 0 | 0 | — | 5 | 4 |
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