A Pratt & Whitney F135 engine powering the F-35 Joint Strike Fighter has completed altitude qualification ground testing.

The F135 designed for the F-35 fighter jet programme and the propulsion system can meet diverse aircraft requirements.

The F135 has been enhanced with technologies developed in other air force and navy technology programmes and derived from technology from the fifth-generation Pratt & Whitney F119 engine.

The final test demonstrates the operability and performance required for Conventional Take-off and Landing (CTOL) and Carrier Variant (CV) Initial Service Release (ISR) for the JSFs.

The ISR is the US Government approval for F135’s operational use and gives Pratt & Whitney the approval to deliver and field production of F135 engines.

The test lasted for 126 hours and evaluated the F135 engine’s air start capability and augmentor performance.

The test also demonstrated and verified the performance of critical systems such as in-flight throttle response, inlet compatibility, engine ice protection and combustor stability.

The final test period was the longest continuous test period completed to date on the F135 programme at 38.7 hours.