Originally Posted by
SLFstu
Apparently the FAA mandates that for US operators all aircraft faults that require maintenance actions are to be reported within 28 days of occurrence. (Yes, for all items big or small, even for the simplest things such as loose exit signs or a flat battery pack in a FA emergency flashlight!)
This is not quite correct. Only a subset of items and events are subject to mandatory SDR reporting. The applicable regulation is 14 CFR Part 121.703. It is DEFINITELY not applicable to all items big or small. A loose exit sign, or a flat battery pack in a flashlight would require an SDR because they are part of the passenger emergency evacuation lighting systems, which is listed in 121.703. A loose bathroom sign or a flat battery pack in the in-flight entertainment system would not require an SDR.
An inoperative AOA sensor that did not require the crew to take an emergency action would not require a SDR to be submitted. I read a few of the AOA SDR reports, and they were all associated with conducting a rejected takeoff. The takeaway here is that AOA failure rates may be higher than indicated by the SDR database.
edit: Technically, even an AOA failure that caused an RTO would not require an SDR to be submitted. Bullet (16) would be applicable - "Aircraft components or systems that result in taking emergency actions during flight", and 121.703 defines "during flight" as after the wheels have left the ground.