Boeing KC-97

Boeing KC-97 1)
Boeing KC-97L with license plates of the Ohio Air National Guard
Type:	Tanker aircraft
Design country:	United States
Manufacturer:	Boeing
Commissioning:	1951
Number of pieces:	816 (888 in total)

The Boeing KC-97 was a four-engine air refueling aircraft made in the USA , developed from the Boeing C-97 Stratofreighter ¹⁾ . The upper deck could hold large amounts of cargo through a hatch in the left side of the ship or transfer fuel ( kerosene or jet fuel ) to the lower tanks. Both deck levels were air-conditioned and designed as a pressurized cabin .

¹⁾ The version as a tanker aircraft KC-97 is sometimes incorrectly referred to as a Stratotanker . According to all reputable sources (including Boeing and USAF), however, the KC-97 Stratofreighter is also called. The name Stratotanker only bears the jet-powered successor model Boeing KC-135 .

history

The US Air Force began using the KC-97 from 1951. On March 15, 1951, a Boeing B-47 was refueled for the first time by a KC-97A. From 1956, the machines were gradually replaced by the Boeing KC-135 , as the speed difference between tanker aircraft and fighter aircraft to be refueled was too great. The KC-97 had almost flying at top speed while being fueled at the refueling jet aircraft almost to the stall had to slow down. The KC-97s were then used as reserve machines for the US Air Force and the Air National Guard . In 1973 the machines were finally taken out of service. Boeing built a total of 811 units, of which 219 were KC-97E and 592 KC-97G with external additional tanks. The KC-97 had four Pratt & Whitney R- 4360-59 engines, each with 3500 horsepower. They were powered by gasoline, while they mainly transported kerosene. The upgraded version of the G-KC-97L received two additional jet engines of the type General Electric J47 -GE-23 for improved aircraft performance at high altitudes.

The KC-97 was vital to the Boeing B-47 missions of the early 1950s. The flights from the Arctic Thule Air Base on Greenland are an example . The machines had to start at −40 ° C. The navigation of the KC-97 in the arctic winter required a high level of concentration.

The Boeing 377 Stratocruiser long-haul passenger aircraft was developed based on the Boeing C-97 . It was built from 1947 to 1950 and had a capacity of 55 to 117 people in a pressurized cabin . In total, only 56 of them were built.

A number of KC-97s survived to this day. One of them, the Angel of Deliverance , flew for the Berlin Airlift Historical Foundation and is still airworthy today. Other machines are in the National Museum of the United States Air Force at Wright-Patterson Air Force Base in Dayton, Ohio , the March Field Air Museum in Riverside, California, and the Carolinas Aviation Museum in Charlotte, North Carolina .

production

Approval of the KC-97 by the USAF:

version	1950	1951	1952	1953	1954	1955	1956	TOTAL
A.	2	1						3
E.		43	17th					60
F.			106	52				158
G				154	233	127	78	592
TOTAL	2	44	123	206	233	127	78	813

Modifications to the KC-97:

version	out	1963	1964	1965	1966	1970	1971	TOTAL
F.	C-97F	4th						4th
L.	KC-97G			45	11	5	21st	82
TOTAL		4th		45	11	5	21st	86

As of 1960, the E and F versions were largely retired, while the KC-97G was used for a number of conversions. As early as 1953, the three KC-97A had been converted into C-97A, in 1955 two KC-97G into YC-97J and between 1962 and 1967 a total of six KC-97F had been converted into C-97F.

Versions

The versions of the C-97 Stratofreighter are listed in the main article Boeing C-97 .

KC-97A

Conversion of three C-97A to tanker aircraft . After successful tests, converted back to the C-97A.

C-97E

KC-97E converted into transporters.

KC-97E

Series version for air refueling with 2610 kW R-4360-35C engines, 60 were built.

C-97F

KC-97F converted into transporters.

KC-97F

KC-97E with 2800 kW R-4360-59B engines, 159 were built.

C-97G

135 KC-97G converted into transporters.

EC-97G

Conversion of at least three KC-97Gs for electronic reconnaissance . The EC-97G 53-106 was used by the CIA (with USAF registration) for reconnaissance in the air corridors to West Berlin.

KC-97G

Production version that could be used as a tanker and transporter. Equipped with two additional tanks under the wings, 592 were built.

GKC-97G

Five KC-97G used for training on the ground.

JKC-97G

Equipping a KC-97G with an additional General Electric J47-GE-23 jet engine under the wings, later classified as KC-97L.

HC-97G

Conversion of 22 KC-97Gs as lead aircraft for SAR operations .

KC-97H

Equipping a KC-97F with the US Navy hose refueling system .

YC-97J

Equipping two KC-97Gs with four Pratt & Whitney YT34-P-5 turboprops, each with an output of 4250 kW . Although successful, other modifications were canceled in favor of the Boeing KC-135 .

C-97K

KC-97G converted into troop transports.

KC-97L

Equipping 81 KC-97G with an additional General Electric J47-GE-23 jet engine under the wings.

Technical specifications

A KC-97L refueling two A-7 Corsair IIs

Parameter	Data
Length:	35.89 m
Wingspan:	43.05 m
Wing area:	164.3 m²
Height:	11.68 m
Drive piston engines:	four Pratt & Whitney R- 4360-59 radial engines with each 3,800 hp (approx. 2,800 kW)
Jet engine propulsion:	Two General Electric J47 GE-23 turbo jets
Top speed:	643 km / h
Range:	3,700 km
Crew:	five men
Service ceiling:	9,144 m
Empty weight:	37,421 kg
All-up weight:	69,400 kg

See also

• List of aircraft types

Web links

Commons : KC-97 Stratofreighter  - Album with pictures, videos and audio files

• KC-97 in the National Museum of the United States Air Force
• Airworthy KC-97 Angel of Deliverance
• C-97 / KC Stratofreighter. In: History. Boeing, 2017, accessed January 2, 2018 . 

Individual evidence

1. ^ Peter M Bowers : Boeing Aircraft since 1916. Putnam Aeronautical Books, London 1989, ISBN 0-85177-804-6 , pp. 365-371.
2. ↑ Statistical Digest of the USAF 1951, p. 158; 1952, p. 158; 1953, p. 185; 1954, p. 70; 1955, p. 89; 1956, p. 92; 1957, p. 98
3. ↑ Statistical Digest of the USAF 1960-1972, table "Gains and Losses"
4. ↑ Statistical Digest of the USAF 1950 to 1972, table "USAF Aircraft Gains and Losses"; 1956, p. 117 ff., 1961, p. 97 ff.