US Navy aviators seen piloting Air Force F-35A Lightning II

A U.S. Navy unit that tests out weapons and aircraft was recently spotted flying one of the U.S. Air Force’s fifth-gen fighter jets as part of an exchange between the two services, the Navy confirmed to Military Times.

Unit insignia of U.S. Navy Air and Test Evaluation Squadron 9, or VX-9, based out of Naval Air Weapons Station China Lake, California, was spotted on an F-35A Lightning II variant on Jan. 23 by aviation enthusiasts on social media.

A spokesperson for the F-35 Joint Program Office subsequently confirmed the Navy’s flying of the aircraft in an emailed statement to Military Times.

While the Air Force’s F-35A is a conventional takeoff and landing fighter, the Navy operates the carrier-based F-35C variant. The Marine Corps, meanwhile, pilots the F-35B short takeoff and vertical landing variant.

The Air Force delivered the aircraft to the Navy through a service agreement, the spokesperson said.

As of December 2025, the Navy has reportedly accepted delivery of nearly 90 of the carrier-based F-35C aircraft, the spokesperson added.

While the F-35 Joint Program Office was unable to state the catalyst for the exchange, a U.S. Navy official told Military Times that other Navy test units have previously flight-tested aircraft from other services.

A characteristic shared between the F35-A and C variants is their mission systems, the defense official said. For testing purposes, one service’s aircraft could be used by another branch. In that case, according to the official, the F-35, whether the A or C, would suffice.

Differences between the F-35C and A include the former’s basket refueling versus the latter’s boom refueling, as well as the F-35C’s “ailerons and folding wings, larger wing and tail area, and stronger landing gear and tailhook,” the spokesperson told Military Times.