Originally Posted by
WillowRun 6-3
Question.
the post by Musician provided the background for the exemption pertinent to this discussion. Part of that background states, "Previous engineering simulations have shown that the 787 airplane is controllable for detected failures that cause UHT; however, it was recently observed that a combination of a high crosswind and UHT may not be controllable for operations on or very near the ground...."
In the 2019-2020 progress of the thread, tdracer referenced an incident involving perhaps an aircraft in Egypt(Jan. 21 2019, 04:38). Also, however, an incident with a Saudi Arabian Airlines 737-200 (Sept. 6, 1997) was referenced, also referring to NTSB A-98-67-70 (Aug. 11, 1998).
I'm fairly certain that @tdracer simply misremembered the country, because the details fit, and the Saudi event is referenced everywhere while the Egyptian event is not (and its details don't fit).
So the question - which I'm hoping justifies interrupting the qualified professionals' discussion because the background to the exemption could become relevant to efforts to reform FAA certification processes - is this: was it the incident involving the Saudi Arabian Airlines aircraft that had been, quote, recently observed, unquote? Maybe the timing of the incident on one hand, and the request for the exemption, do not align in the relevant way. For that or any other reason, if the "recently observed" datum was from something else, what was it?
There are several assumptions here that are not warranted, "qualified professional" first and foremost
"It was recently observed" does not imply an event; it could be a study like "
Research on Risk Assessment with Uncontrollable High Thrust for Civil Airplane" (but not this exact one as it came out later). As far as I could ascertain, the Saudi event occurred in 1997, the NTSB issued a recommendation in 1998 (also quoted by me, albeit hidden by spoiler), and the FAA then started to enforce the existing "single point of failure" regulations with regard to UHT for type certifications from some point on forward, which led to the aircraft manufacturers requesting these exemptions. I don't have an exact timeline on that.