Swiss Internal Report Flags F-35 Afterburner Issue

A department in the Swiss government tasked with defense procurements has flagged a problem with the F-35 jet - the engine’s afterburner causes overheating at the aircraft’s rear.

The Military Intelligence Service (SRM) reported what it calls a “serious” problem with the F-35B and F-35 jets, to the Swiss Federal Department of Defense (DDPS) which compiled an internal report.

“The F-35B and F-35C jets suffer from serious problems when using afterburning. Post combustion, an excessive increase in heat at the rear of the aircraft has been observed,” wrote PageSuite, citing the DDPS document.

A jet engine’s afterburner component provides an increase in thrust for supersonic flight, take-off and in combat situations.

The heat from afterburner exhaust causes the F-35 B/C jets to experience “bubbling and blistering” of its radar-absorbent material (RAM) and of horizontal tail surfaces and boom.

Sensitive sensors buried inside the skin of the rear tail surfaces are also susceptible to damage.

The US military reportedly faced the same problem in 2011: F-35B and F-35C flying near their maximum service ceiling of 50,000 feet damaged themselves using their afterburners to attain speeds of Mach 1.3 and 1.4.

Following the incident, the Marines instituted a policy requiring F-35B pilots not to engage afterburners for more than 80 seconds cumulatively at Mach 1.3, or 40 seconds at Mach 1.4. Navy F-35C pilots have 50 seconds at Mach 1.3 to ration. Three minutes of non-afterburning flight to cool down the tail area was suggested to “reset” the afterburner allowance.