The Boeing C-97 Stratofreighter is an American four-engine heavy transport developed from the B-29 Superfortress and B-50, with a second fuselage lobe added on top of the bomber's fuselage. The XC-97 first flew on 9 November 1944, and 77 transports and 811 KC-97 tankers followed for the US Air Force, which flew them until the 1970s. Developed by Boeing.
The Boeing C-97 Stratofreighter is an American four-engine heavy transport developed from the B-29 Superfortress and B-50, with a second fuselage lobe added on top of the bomber's fuselage. Developed by Boeing.
See Specifications for full detail.
The Boeing C-97 Stratofreighter is an American four-engine heavy cargo aircraft built by Boeing for the US Air Force. It was developed from the B-29 Superfortress and B-50, took a second fuselage lobe on top of the bomber's fuselage and wings, and flew for the first time as the XC-97 on 9 November 1944. [1]
Boeing built 77 C-97 transports and 811 KC-97 tankers, and Strategic Air Command operated C-97s from 1949 to 1978. The civil Boeing 377 Stratocruiser grew out of the same design. [1]
Design work began in 1942, using the wings, tail and engine layout of the B-29 almost unchanged with a new two-lobe fuselage on top of the bomber's. The XC-97 first flew with 2,200 hp Wright R-3350 engines, and later aircraft from the tenth onward took 3,500 hp Pratt & Whitney Wasp Major engines and the B-50's taller fin and rudder. On 9 January 1945 the first prototype flew from Seattle to Washington, D.C., in 6 hours 4 minutes with 20,000 lb of cargo. [1]
Clamshell doors under the tail had two retractable ramps for driving cargo in, and the doors could not be opened in flight, though they could be removed for airdrops. The useful payload of 35,000 lb covered two 2.5-ton trucks, towed artillery or light tracked vehicles such as the M56 Scorpion. It was not a tactical airlifter able to deliver to primitive forward bases. [1]
Production ran to 77 transports and 811 tankers. The tanker line began with the KC-97E (60 built) and KC-97F (159), and the KC-97G (592) was the main version, a dual-role tanker and transport with underwing fuel tanks. Boeing introduced the flying boom refuelling system on the KC-97 in 1950. [1] [2]
After 1956 the USAF gradually replaced KC-97s with the Boeing KC-135 jet tanker. From 1964 some were fitted with two J47 turbojets, becoming KC-97Ls, which were faster and served mainly with the Air National Guard. The Air Force retired its last C-97 and KC-97 in 1973, while the Air Force Reserve and Air National Guard kept some as tankers or search and rescue aircraft. [2]
A YC-97A, 45-59595, flew with the 1st Strategic Support Squadron in the Berlin Airlift in April 1949 and had a landing gear accident at Gatow, and it was repaired after the blockade ended. In Korea C-97Cs, designated MC-97C, evacuated casualties, and the type served in Vietnam. Some Strategic Air Command C-97s were used as airborne command posts. [1]
In the late 1960s C-97s flew relief missions into Uli airstrip at night and at treetop level during the Biafran airlift, and at least two were lost. The Israeli Air Force adapted Stratocruisers and KC-97s when the C-130 was unavailable, and on 17 September 1971 an Israeli C-97 serving as an electronic countermeasures platform about 12 miles from the Suez Canal was shot down by an Egyptian SA-2 missile. From 1967 Air National Guard and Air Force Reserve tankers supported USAF and NATO units in Europe for ten years under Operation Creek Party. [1] [2]
The Boeing 377 Stratocruiser was a transoceanic airliner built on the C-97 design, with optional sleeper cabins and a lower-deck lounge. It first flew on 8 July 1947 and 56 were built. [1]
Aero Spacelines later built the Pregnant Guppy, Super Guppy and Mini Guppy as related developments of the same design, although the sources checked give no further detail on them. [1]
Several C-97s were lost in the 1950s. A C-97A disappeared between Lajes Field and Westover on 15 October 1951 with 11 crew, and a C-97C disappeared over the Pacific on the way to Tokyo on 22 March 1957 with 67 aboard, the deadliest C-97 loss. On 8 August 1957 a C-97 lost a propeller, which damaged another engine, and flew about five hours at 150 ft to land at Hilo, Hawaii. A C-97A vanished between Honolulu and Kwajalein with seven crew on 19 January 1958, and debris found 277 miles southwest of Honolulu was later confirmed as wreckage. On 29 June 1964 an HC-97G and an HC-54D collided off Bermuda while doing pararescue training and photography for the NASA Gemini programme, and 17 people died and seven survived. On 30 July 1987 a Belize Air International C-97G crashed on the Mexico City to Toluca highway after its cargo shifted, killing 5 of the 12 aboard and 44 people on the ground. [1]
Six preserved aircraft are listed here. The best known, 52-2718 Angel of Deliverance, was delivered to the USAF in 1954 as a KC-97G and flew with Strategic Air Command units at Lincoln, Altus, Malmstrom and Plattsburgh. It moved to the Air National Guard in Milwaukee in August 1964 and to Salt Lake City in September 1972, where it deployed to Rhein-Main for Operation Creek Party, and it went to storage at Davis-Monthan in September 1976. It was bought at auction in 1986 and converted to a C-97G cargo aircraft, then seized by the US Marshals Service in 1988 and sold to Grace Aire, which flew humanitarian cargo to South America and fish in Alaska. The Berlin Airlift Historical Foundation bought it on 22 April 1996, flew it to Greybull, Wyoming, in October 1998 and painted it in 2000 as YC-97A 45-59595, the only C-97 used in the Berlin Airlift. It flew again on 7 November 2017 after 15 years on the ground, and since 2019 it has been parked at the Mid-Atlantic Air Museum in Reading, Pennsylvania, waiting for an engine and an inspection. The foundation owns four C-97s and bought a complete C-97G at Greybull in 2021 as a source of parts. [3][4] Other survivors are 52-2626 at the Pima Air & Space Museum in Tucson, the KC-97L 52-2630 at the National Museum of the US Air Force, which flew with the Ohio Air National Guard in Operation Creek Party and was named Zeppelinheim by that town's mayor on 7 June 1973 and a C-97K at the Israeli Air Force Museum at Hatzerim. [1][2]
The Boeing C-97 Stratofreighter has a top speed of 326 kn (375 mph / 604 km/h).
A total of 888 were built.
No, the Boeing C-97 Stratofreighter has been retired. It retired in 1978.
The Boeing C-97 Stratofreighter first flew on November 9th 1944.
The Boeing C-97 Stratofreighter has a range of 4,300 mi (6,900 km); ferry range 5,760 mi (9,270 km).
A selection of surviving C-97 family aircraft, taken from a single source rather than a full census.
One C-97G, 52-2718 Angel of Deliverance, is airworthy with the Berlin Airlift Historical Foundation, painted as YC-97A 45-59595. It flies rarely and no verified Flightradar24 type code was found for it, so sightings are best tracked through the foundation's own announcements.
| Performance | |
| Max Speed | 326 kn (375 mph / 604 km/h) |
|---|---|
| Cruise SpeedCruise Speed — The economical speed an aircraft sustains for the bulk of a flight - lower than maximum speed, chosen for the best balance of time and fuel burn. Glossary → | 300 mph |
| RangeRange — How far an aircraft can fly without refuelling. Quoted figures vary with payload, speed and reserves - see also ferry range and combat radius. Glossary → | 4,300 mi; ferry range 5,760 mi |
| Service CeilingService Ceiling — The highest altitude at which an aircraft can still climb at a useful rate (typically 100 ft/min). Above it, the air is too thin to keep climbing meaningfully. Glossary → | 35,000 ft |
| Airframe & Weight | |
| Wingspan | 141 ft 3 in |
| Length | 110 ft 4 in |
| Height | 38 ft 3 in |
| WeightMTOW — Maximum Take-Off Weight - the heaviest an aircraft is certified to be at the start of its take-off run, including fuel, crew, payload and the aircraft itself. Glossary → | empty: 82,500 lb; MTOW: 175,000 lb |
| Power & Payload | |
| Engines | 4 x Pratt & Whitney R-4360B Wasp Major radial engines, 3,500 hp each, driving four-bladed Hamilton Standard constant-speed fully feathering propellers |
| Crew | 5 to 6 (pilot, copilot, navigator, flight engineer, one or two loadmasters) |
| CapacityPayload — Everything an aircraft is carrying that isn't the aircraft or its fuel: passengers, cargo, or weapons. Payload and fuel usually trade off against each other. Glossary → | 134 troops or 69 stretchers. The useful payload was 35,000 lb, enough for two 2.5-ton trucks, towed artillery or light tracked vehicles. |
| Program & Service | |
| Manufacturer | Boeing |
| Origin | United States |
| First Flight | November 9th 1944 |
| Service Entry | 1949 |
| Retired | 1978 |
| Number Built | 888 |
| Unit Cost | Not publicly disclosed - no unit cost for the C-97 or KC-97 was found in the sources checked |
7 notable events involving the C-97 Stratofreighter, 1947 to 1987. 154 deaths are recorded across the 6 of these with a figure listed. Curated rather than exhaustive.
XC-97 43-27472 crashed near Wright-Patterson Air Force Base and burned. Five of the seven crew were killed.
C-97A 49-2602 disappeared on a flight between Lajes Field in the Azores and Westover Air Force Base. The crew of 11 were never found.
C-97C 50-0702 disappeared over the Pacific on the way to Tokyo with 67 aboard. It is the deadliest C-97 incident.
HC-97G 52-2773 collided with HC-54D 42-72590 off Bermuda. Seventeen people were killed and seven survived.
The relief aircraft N52676 crashed on approach to Uli airstrip during the Biafran airlift. All five on board were killed.
An Israeli C-97 serving as an electronic countermeasures platform about 12 miles from the Suez Canal was brought down by an Egyptian SA-2 missile.
C-97G HI-481 crashed on the Mexico City to Toluca highway after its cargo shifted. Five of the 12 aboard and 44 people on the ground were killed.
| XC-97 / YC-97 / YC-97A | Three XC-97 prototypes, six YC-97 cargo aircraft and three YC-97A troop carriers. The first prototype flew with 2,200 hp Wright R-3350 engines. From the tenth aircraft onward the type used 3,500 hp Pratt & Whitney Wasp Major engines and the B-50's taller fin and rudder. |
| C-97A / C-97C | The first production transports: 50 C-97As, three of which were temporarily converted to KC-97A tankers with a boom, and 14 C-97Cs. The C-97Cs that carried casualties out of Korea were designated MC-97C. The C-97 was a strategic carrier, with a payload of 35,000 lb and clamshell doors under the tail. |
| KC-97E / KC-97F | The first tanker production versions, 60 KC-97Es followed by 159 KC-97Fs. The KC-97F used R-4360-59B engines. Boeing introduced the flying boom refuelling system on the tanker in 1950, and the KC-97s served Strategic Air Command until the KC-135 jet tanker replaced them, a process that began after 1956. |
| KC-97G | The main production tanker, with 592 built as dual-role tanker and transport aircraft with underwing fuel tanks. Of these, 135 were converted to C-97G transports, 22 to HC-97G search and rescue aircraft and 5 to GKC-97G ground instruction airframes. The airworthy 52-2718 is a C-97G. |
| KC-97L | Eighty-one KC-97Gs fitted with two General Electric J47 turbojets of 5,970 lbf under the wings, converted from 1964. The jets made the aircraft faster, with a maximum speed of 400 mph, and the type served mainly with the Air National Guard. The KC-97L displayed at the Air Force museum, 52-2630, was named Zeppelinheim in 1973. |
| C-97K / YC-97J | The C-97K was a troop transport conversion of 27 KC-97Gs. The YC-97J was a conversion of two KC-97Gs with four 5,700 hp Pratt & Whitney YT34-P-5 turboprops, originally designated YC-137. The Israeli Air Force Museum at Hatzerim displays a C-97K, 035 (4X-FPO), and the Israeli Air Force also flew converted KC-97s and Stratocruisers. |
| VC-97D / EC-97G / KC-97H | Special conversions: three VC-97D command post aircraft, three EC-97G electronic intelligence aircraft, one of which the CIA used over the West Berlin air corridor, and a single KC-97H fitted experimentally with a probe-and-drogue refuelling system. Strategic Air Command also flew some C-97s as airborne command posts. |
| Boeing 377 Stratocruiser | The civil airliner developed from the C-97, with optional sleeper cabins and a lower-deck lounge. It first flew on 8 July 1947 and 56 were built. The Aero Spacelines Pregnant Guppy, Super Guppy and Mini Guppy are listed as related developments, but the sources checked give no detail on them. |
No photos added yet for this aircraft.
A selection of surviving C-97 family aircraft, taken from a single source rather than a full census. One C-97G is airworthy.
No newly associated news articles since this aircraft was added to PlanesDB. When new news articles are published, they will be automatically added and tracked here.
Numbered as cited in the Overview article. Click a reference to see where it's used.
Additional reading you might find interesting...
PlanesDB entries are living documents - this is how this one has evolved, and who helped make it happen. Spotted something out of date? Help update it.
