U.S. Air Force Concludes Redesigned TF33 Component Testing

January 3, 2017

William Kucinski

The TF33 Pratt & Whitney engine undergoes testing in an AEDC sea level test cell, to verify and validate newly redesigned components of the engine.

U.S. Air Force engineers successfully completed verification and validation of new Pratt & Whitney TF33 engine components at the Arnold Engineering Development Complex in Tennessee. These components—a newly redesigned inlet case and turbine exhaust case—are part of a package of upgrades developed to keep the nearly 65-year-old Boeing B-52 bomber in service into 2040 and beyond.

AEDC engineer Tyler Holes assists in preparing for testing of the TF33 Pratt & Whitney engine in one of the AEDC sea level test cells.

The accelerated mission testing simulated approximately one-half of an overhaul cycle of testing on the engine, running approximately 690 sea-level operating hours to test the structural integrity and durability of the new inlet and exhaust cases. Multiple performance calibrations were completed to determine if there were any new performance standards that stemmed from the redesigned components.

The test was requested by the TF33 Systems Program Office of the Air Force Life Cycle Management Center Propulsion Directorate (AFLCMC/LPS) at Tinker Air Force Base.

Dropping fuel prices and costly plans to re-engine the B-52H led P&W to develop upgrades that would reduce the cost of maintaining TF33 engines, which celebrated a 55th flight anniversary in March 2016. The new inlet case and turbine exhaust case preclude developing and replacing engine nacelles for the 76 B-52H aircraft still in service.

James Burt, TF33 equipment specialist with the AFLCMC/LPS, commented that working with AEDC on the TF33 accelerated mission testing proved to be an “outstanding experience.”

The nearly 65-year-old Boeing B-52H is still powered by the original P&W TF33, which celebrated its 55th anniversary of flight in March, 2016.

“We have had no engine issues and all test cell issues were worked and resolved very quickly with little to no test down time,” he said. “This has resulted in the smoothest TF33 AMT test to date and allowed the test to complete ahead of schedule.”

The first U.S. Air Force Boeing KC-135E Stratotanker aircraft undergoing flight tests at Edwards Air Force Base on 4 March 1982 after being re-engined with Pratt & Whitney TF33 turbofan engines.

Testing was completed early with 55 successful air periods performed in 61 days. The testbed engine was a 17,000-lb thrust variant used aboard the B-52H Stratofortress airframe.

The last TF33 test was conducted in the ETF C-2 test cell in 1995, during which AEDC characterized cold weather starting techniques between JP4 and JP8 jet fuel.