Pratt & Whitney JT9D

Pratt & Whitney JT9D without disguise

A partially cut open P&W JT9D (Deutsches Museum Munich)

Combustion chamber (cut open)

Pratt & Whitney JT9D on a Boeing 747

The Pratt & Whitney JT9D is a jet engine from the US manufacturer Pratt & Whitney . The first turbofan engine with a high bypass ratio for civilian use was from the mid-1960s for the Boeing 747 developed a new type of large aircraft created. Previously it was subject to the General Electric TF39 as a military engine for the Lockheed C-5 Galaxy; it was then developed into the “civil” JT9D.

The program launch took place in September 1965, the first run in December 1966. 1969 got the approval from the US Federal Aviation Authority, the construction FAA . In December 1970, the Boeing 747 was used in scheduled air traffic.

The JT9D has a high bypass ratio of 5: 1 and initially had a monopoly on this market. Almost all early Boeing 747s were equipped with this engine. However, with the appearance of two competing products, the General Electric CF6 and the Rolls-Royce RB211 , the market share decreased significantly. Technical difficulties, which brought the engine the derisive nickname "Pratt & Geht no more", caused z. For example, Lufthansa decided to replace its first Boeing 747-100 with the JT9D with new 747-200 with GE CF6 at an early stage. Although Pratt & Whitney was able to regain ground with the improved version JT9D-7R4, which appeared in 1982 , it never regained the proportions from the early days. In 1990 production was discontinued in favor of the successor model Pratt & Whitney PW4000 .

In addition to the Boeing 747, the Boeing 767 , the Airbus A300 , the Airbus A310 and the McDonnell Douglas DC-10 could also be equipped with the JT9D. For the last three types of aircraft, however, only a few operators opted for the JT9D and preferred the CF6-50 or CF6-80C engine from General Electric. For example, of the 446 DC-10s, only 42 were equipped with the JT9D under the type designation DC-10-40. Many airlines considered the engine to be tailor-made for the 747, while General Electric did not focus on one type of aircraft.

Web links

Commons : Pratt & Whitney JT9D  - Collection of Pictures, Videos and Audio Files

• Manufacturer page with current information (English)
• Model approval data sheet FAA-TCDS for models JT9D-3A, -7, -7A, -7AH, -7F, -7H, -7J, -20, -20J PDF, English, accessed on March 11, 2012
• Model Approval Data Sheet FAA-TCDS for JT9D-59A, -70A, -7Q, -7Q3, -7R4D, -7R4D1, -7R4E, -7R4E1, -7R4G2, -7R4H1, -7R4E4 PDF, English, accessed March 11 2012

See also: List of aircraft engines