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To: carriage_hill

Although I know nothing about the aircraft, as a retired pilot with many years experience in prop driven aircraft, I doubt that the engine is to blame.

All sorts of weird changes in airflow occur when high performance aircraft change angle of attack or similar changes in attitude.

My suspicion in this case would be that the “slight” course correction caused a disturbance in the airflow to the engine.

For instance a slight skid or sidslip might have caused the fuselage to disturb the airflow, thus causing the engine to lose power.

Only a person highly qualified in that aircraft can answer this question, and I am not that person...but I do know that it is possible.


33 posted on 02/07/2022 11:50:46 AM PST by old curmudgeon (There is no situation so bad that the federal government can not make worse.)
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To: old curmudgeon

I have a ‘few’ hours in a Cessna 172 Skyhawk, and I think you’re right.


39 posted on 02/07/2022 12:01:00 PM PST by Carriage Hill (A society grows great when old men plant trees, in whose shade they know they will never sit.)
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To: old curmudgeon

What they are referring to is called inlet distortion which is a variation in stagnation pressure over the inlet area of the engine. Variations are induced by attitude changes - mainly pitch and yaw - as well as throttling factors that change the near field flow characteristics. Dependent on the robustness of the compressor design and the engine throttling schedule, outlier pressure variations can lead to surge which is mistakenly referred to as compressor stall, which is more often a result rather then a cause of surge.

I don’t know the details of the Hultgren case but it appears that it would be a yaw rate induced surge event leading to engine power loss which she probably tried to counteract with an excessive pitch rate leading to a failed engine side wing stall that then coupled into roll due to asymmetric lift and was unrecoverable due to competing asymmetric thrust moments with the aforementioned yaw rate induced out of balance roll moment.


70 posted on 02/07/2022 1:48:56 PM PST by Regulator (It's fraud, Jim)
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