GE's second XA100 prototype kicks off Phase 2 tests

General Electric's second XA100 adaptive cycle engine has begun Phase 2 testing at the Air Force's Arnold Engineering Development Complex, the company announced today.

The next round of testing, which started March 25, comes after GE wrapped up its first phase in November 2021.

The multimonth Phase 2 work will allow the company to “fill in” its current dataset, leverage more precise measurements, and complete the full-flight envelope for its offering, David Tweedie, GE’s general manager for advanced combat engines, told Inside Defense recently.

“If you want to know if the engine works, we already have that data; we’ve shared it with the Air Force,” he said in an interview at the Air Force Association’s Warfare Symposium earlier this month. “If you want to have the engineers have all the data in hand so they can execute a low-risk [engineering and manufacturing development] program in five years, filling out all that last bit of data for the engineers is what we’re [working toward] at this point.”

Company executives developed the XA100 through the Air Force’s Adaptive Engine Transition Program, in which engine manufacturers are creating prototypes to fit the F-35A conventional variant. Pratt & Whitney, the F-35’s F135 engine maker, is also maturing advanced engine technology through AETP with its own XA101.

The Air Force in late January published a sources-sought listing for the EMD phase of the AETP effort. Called the F-35 Adaptive Engine Replacement Program, the notice directed companies to describe their “capability to enter into a contract committing to the delivery of F-35 engines” and begin low-rate initial production in fiscal year 2028.

Meanwhile, the service is working with the Navy and Marine Corps through the F-35’s Joint Program Office to develop options to incrementally upgrade the current F135 engine, an approach Pratt favors, or replace it.