PPRuNe Forums - View Single Post - AA A321 takes off after smashing ground sign
Old 30th Jul 2022, 11:55
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fdr
 
Join Date: Jun 2001
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On hydraulics, the sizing of hydraulic supply has considerable reserves of volume for operations, [§25.1435(c)], separately, Subpart C covers loads but not rates.

Back a ways the AS350 had a nasty little habit of having a jack stall in one particular manoeuvre... another helicopter on one occasion happened to return back to the manufacturers ramp after a funny, which distorted the rotor blades, the company owner being the driver. Hydraulics can have anomalies, but in this case, my concern is that there is a curiosity in the data, the full data set should exist still and could provide some further insight into whether this was an artefact or a control anomaly.

Q: Do rudder, elevators, ailerons and spoilers use all the same accumulator or are the 3 hydraulic systems working in parallel ? The latter would imply, all accumulators were depleted at the same time.
Each of the 3 systems have accumulators, and a priority valve prioritises flight control supply over all other services. there are also had fuses that could cause anomalies to supply volume. The data should readily show transients, but the data in th public docket is an inadequate subset to assess deeper. All 3 systems, green, blue and yellow, power the rudder by recollection on that bus. A single transient would likely not result in an anomaly of much note, but more could become an issue, and could be latent. This is a wild card but the data suggests that there is a funny that should be explained. Weird stuff doesn't just happen to marines.

Last edited by fdr; 30th Jul 2022 at 12:11.
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