But the Pentagon earlier this month said it would continue using lithium-ion batteries on the F-35 since they were made by different manufacturers from those used on the 787, and had been found to safe after extensive testing.

Hawn said an initial assessment of the Feb. 14 incident involving BF-2, one of the Marine Corps’ short takeoff, vertical landing variants, had linked the problem to a software issue, not a problem with the auxiliary power unit’s hardware.

The whole system was being sent to Honeywell for a closer inspection and development of a permanent fix, she said, noting that the plane was going through developmental testing specifically to find and fix any such problems.

“This is the purpose of test, development & initial training in any program; identify discrepancies, develop fixes, and put them in place to ensure safety of operations,” she said. “Engineering assessment of issue indicates minimal risk, and (a) relatively uncomplicated resolution.”

Honeywell spokesman Nathan Drevna said the company was aware of the Feb. 14 incident and would inspect the system carefully once it arrived at the company’s testing facility.

“The pilot landed safely. The Honeywell-related products are being shipped to our testing facility so we can quickly inspect and determine next steps with our customer,” Drevna said.