Pratt & Whitney JT3D

From Wikipedia, the free encyclopedia

The Pratt & Whitney JT3D is an early turbofan engine which is still in service today, mainly on military aircraft.

Pratt & Whitney produced over 8000 JT3Ds between 1959 and 1985. The engine is a turbofan derivative of the Pratt & Whitney JT3C turbojet and is also known by its military designation, the TF33.

After long service for both airlines and air forces the number of JT3D powered aircraft is steadily decreasing. 135 KC-135s use the JT3D while 354 were fitted with CFM International CFM56 engines which provide greater thrust and increased operational flexibility due to their lower noise footprint. The noise of the JT3D is one of the reasons NATO has debated re-engining their E-3 Sentry AWACS fleet, with the aircraft subject to restrictions that modern-engined aircraft are not. Operational flexibility would be further increased due to the ability of higher power engines to increase the ceiling of the aircraft, extending the horizon for radar surveillance, e.g RAF, French and Saudi E-3s routinely fly higher than NATO/USAF counterparts. However the main funding for such a programme would come from the United States who most likely wish to upgrade their own fleet first.

Another well known aircraft which was fitted with the JT3D (in TF33 form) was the Boeing B-52H Stratofortress. The 'H' model of the B-52 was the only iteration of the famous bomber to be fitted with turbofan engines, and is the only model remaining in US Air Force service. It is expected to remain as a mainstay of the USAF heavy bomber fleet until at least 2030.