After a cabin ground fire destroyed a first-generation Cirrus SF50 Vision Jet, the FAA issued emergency airworthiness directive AD 2020-03-50, which grounds the fleet of jets until faulty audio amplifier circuit cards are removed from the cabin.
In the aircraft that melted on the ramp, the FAA wrote in its AD that the pilot observed smoke coming from the right rear cabin sidewall. The smoking components are audio amplifiers that are used to drive the 3.5-MM audio/microphone jacks in the passenger cabin. The part number of the defective circuit card is P/N 38849-01, and the AD says to simply remove all 12 of them from the cabin before the next flight. That generally takes eight hours labor to remove the interior, the circuit cards and put it all back together.
Cirrus has been on this before the AD, and already issued service bulletin SBA5X-23-03 for compliance instructions. To date Cirrus has made 97 percent of the SF50 fleet airworthy again through its ASSIST mobile technical team and established service centers. It said over 170 Cirrus jets are back flying since the bulletin was issued on Feb. 7, 2020. Nailing the communication effort, all Cirrus SF50 customers were contacted within 24 hours of the bulletin’s release.
Old EE joke:
What makes semiconductors work?
Smoke.
Huh?
After the smoke comes out, they don’t work anymore.
An uncontained cabin fire because of a small low voltage component?
I’d assume that Cirrus also need to ground the fleet to insure that FAR 25.853 was followed.
The Vision Jet is a Part 23 vehicle.
Small consolation when your multi-million dollar jet plane burns to the ground. If I paid for one then I would have would have assumed that the new plane was designed to burn up like a wicker cabinet…
First of all, it was certified under Title 14 of the Code of Federal Regulations, not the old FARs. They went away 15 years ago (I’m in the cert business.)
And low-voltage ain’t the issue, it’s relatively high current that will cause things to heat up and catch fire. It’s easy to quell tens of thousands of volts at low current, with no fire danger. Give me five volts at five amps, and I’ll get a fire started.
“Give me five volts at five amps, and I’ll get a fire started.”
Precisely!
The issue is that a newly design aircraft burned to the ground because of a smolder the size of a quarter. It’s not the components fault, they can and will fail. The problem is a modern design that seems to have forgot the basic Apollo 1 lessons.
Edit: Designed NOT to burn up like a wicker cabinet…
We let the Chinese buy all the aviation companies. Surely we are getting what we deserve.
The Apollo 204 fire was a consequence of a short circuit source of ignition, in a 100% oxygen environment. The impossible-egress vehicle design didn’t help the outcome.
Sound and lighting apparatus often have failure modes for which source-current overload protection is ineffective. Temperature-sensing circuitry, with cutoff authority often is necessary.
I have no Vision Jet schematics, so I can’t determine – and won’t speculate – regarding the pathology of this incident.
Apollo 1, as in very small ignition source and the whole cabin gets torched.
As far as impossible-egress, think of this happening at 20,000 in your Vision Jet.
This is unacceptable for a modern design regardless if it was “legal”.
My opinion.
What kind of disaster is acceptable in a modern design?