After a disastrous ground fire, the FAA has adopted an airworthiness directive  (AD), for the Cirrus Vision SF50 Jet that requires the removal of the headset amplifier and microphone interface circuit boards for the 3.5 mm audio and microphone jacks.

On December 27, 2019, a Cirrus SF50 Vision Jet caught fire prior to departure from Santa Monica Municipal Airport, California, USA. The private pilot was not injured, and the aircraft sustained substantial damage.

Upon arrival at the aircraft, the pilot began to perform preflight checks and completed a walkaround. After boarding and closing the cabin door, he continued with the checks and observed haze in the cabin accompanied by a faint smell of smoke. He continued to follow the checklists and after starting the engine, the smoke smell became stronger, and he decided to terminate flight preparations, and have a mechanic examine the aircraft.

After completing the engine shutdown, he opened the main cabin door, and began to see smoke issue from the armrest area of the number 5 (right centre) passenger seat. A mechanic arrived at the aircraft with a fire extinguisher within a few minutes, however the smoke had become dense, and was now streaming out of the cabin door. A few minutes later, flames began to emerge from the cabin, and by 11:55 the cabin was completely engulfed. The fire department arrived at 12:02, and the fire was extinguished.

The aircraft sustained extensive thermal damage, with fire consuming the cabin roof and destroying the cabin contents from the aft wall of the parachute (CAPs) enclosure through to the engine inlet nacelle, with fire damage more extensive on the right side of the airframe. Fire had consumed the lower right walls of the cabin down to the wing root, with only composite cloth remaining. The right wing was intact, but sustained thermal damage to the upper skin from the root outboard about 4 ft short of the tip. The left wing, and lower left exterior skins of the cabin were largely free of fire damage.

An investigation determined the probable root cause was a malfunction of the headset amplifier and the microphone interface circuit card assemblies for the 3.5 millimeter audio and microphone jacks. This malfunction likely resulted in an electrical short and subsequent uncontained cabin fire without activating circuit protection.

On February 14, 2020, the FAA issued an emergency AD to disconnect and remove the headset amplifier and microphone interface circuit card assemblies for the 3.5 mm audio and microphone jacks on all Cirrus SF50’s.

The AD, sent to all US owners and operators of the Cirrus Vision Jet, was originally created as an Emergency AD, in February 2020, prompted by a ground incident when a Vision Jet pilot noticed smoke rising from the right sidewall interior panel. The FAA says failure to comply with this AD could lead to an uncontained cabin fire that could injury people onboard and lead to a loss of aircraft control. No special flight permits will be issued to address this issue. The only exceptions to this AD are operators who previously complied with the Emergency AD.

Originally published as a safety-of-flight issue, the original AD did not allow for public comments. The agency is now requesting comments, data and suggestions not later than July 27, 2020 through its Regulations.gov site.

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