We can certainly come up with reasons it should have done more and there may be more information which the US Attorney has but is not at this point disclosing (standard procedure in federal criminal cases).
FWIW, pilots and instructors do not typically face immediate revocation or suspension after one or even two accidents where the only damage is to the aircraft. Reading through the events as alleged in the Indictment, I didn't see much out of the ordinary on the FAA's end. Then again, we don't "the rest of the story" at this point. And, of course, if you liked the old beat them over the head from the beginning FAA, I'm sure there are others who will agree with you.
Anyway, without taking sides, to answer your question, the Indictment indicates that after the second accident in March 2021, the FAA received the hotline complaint. After investigating it, the ASI scheduled a 709 ride in May. Yes, McPherson ignoring the 709 letter should have been a red flag, but the FAA will typically try to obtain compliance rather than pursue certificate action. So they rescheduled the 709 ride, which took place September 29, 2021. McPherson failed.
Instead of pursuing revocation, the FAA did what it usually does in this situation. Instead of revocation, the FAA accepted a voluntary certificate surrender and issued a temporary certificate such as the photo, which basically allows McPherson to fly solo to prepare for a re-test. It prohibits passengers and expired, as typical, in 1 month, here November 8, 2021. As of that date, revocation or not, McPherson had no pilot certificate at all.
The accident causing the victim's death was almost a year after
he had no certificate of any kind.
Other than that McPherson continued to fly and instruct (9 times while he had the limited temporary and another 31 times when he had no certificate at all) we have no idea at this point what else occurred. Did anyone make another hotline complaint? Did the flight school do some extra due diligence? I doubt the FAA follows up on people who surrender their certificates absent complaints.
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