USMC pins 2023 F-35B crash on pilot error

A US Marine Corps investigation has attributed the 17 September 2023 crash of a Lockheed Martin F-35B fighter to pilot error.

In an investigation report, sections of which are heavily redacted, the USMC contends that while the F-35B’s (BF-66) systems were degraded, the aircraft was still flyable when the pilot ejected.

While conducting an ILS approach to runway 15 of Joint Base Charleston in South Carolina in the early afternoon, the pilot experienced a series of electrical failures.

After entering short take-off and vertical landing (STOVL) mode for the landing, the pilot experienced several display malfunctions, including with his helmet mounted display (HMD). The jet’s navigation and communication capabilities were also degraded.

The HMD came back on with several cautions and advisories, and the pilot decided a runway landing was not feasible. He decided to convert the aircraft conventional take-off and landing (CTOL) mode.

“Upon climb-out, [the pilot] discovered that he had lost communication with Charleston Tower and his wingman,” says the report.

“Seconds later his HMD returned accompanied by additional cautions and advisories. Additionally, he perceived the aircraft was not responding to pilot commands to convert out of Mode 4 (STOVL).”

The pilot’s HMD went down again with the aircraft at 1,900ft. The pilot had no visible reference to the horizon and ground and was unsure of his instruments. He also perceived that the jet was not responding to his command to return to CTOL mode.

Perceiving that the aircraft had departed controlled flight, the pilot ejected. He landed safely in the backyard of a house.

The aircraft, however, completed its conversion to CTOL mode and flew unmanned for 11min 21s before crashing in a wooded area. It took over 12h for searchers to find the aircraft, which was destroyed in the crash.

“The investigation concludes that the mishap occurred as a result of pilot error, in that he incorrectly diagnosed an [out-of-controlled flight] emergency and ejected from a flyable aircraft – albeit under extremely challenging cognitive and flight conditions,” says the report.

It contends that the pilot’s decision was “inappropriate” because commanded inputs were in progress. Moreover, standby flight instruments were providing accurate data, with the backup radio at least partially functional. It notes that the aircraft continued to fly “for an extended period” after the pilot’s ejection.

The report acknowledges, however, that the pilot – “highly experienced” in the Boeing AV-8B and a “novice” in the F-35 - may have become disoriented amid a high workload situation with no visual cues outside the cockpit.