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Old 25th Jul 2009, 18:06
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Hyperveloce
 
Join Date: Jun 2009
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How to judge whether a stall alarm is justified or not ?

...if you have lost a major indicator like airspeeds and if you are at high altitude with a little aerodynamic margin (GPS ground speed insufficient) and no visibility ?

would the pich & thrust interplay do it ? a few days ago, a pilot asked to the other pilots: flying without airspeeds at FL350 with an AoA~4°, your pich/altitude remain well under control, would you think you are approaching a stall ? (as far as I understand). would such a behaviour (evolution) of the pich/altitude (given the thrust, AoA & altitude) be a non ambiguous indication of a sufficient airspeed ?

if you have more time (assuming you are not subjected to multiple stall alarms), can you assess your aerodynamical authority by inducing a smooooooth vertical manoeuver ? (loosing a bit of altitude and stabilizing it with a slight attempt to regain altitude to assess the airframe authority).

Would you see means to appreciate (swiftly) whether a stall alarm is justified or not ? How will you do if it happens to you ?
Jeff

PS) Automation is not bad (simply you can't rely on it and you have to know it intimately as it is a critical part of your plane) and sometimes, men & automata (Alpha prot.) collaborate for the best:
http://www.ntsb.gov/events/2009/Weehawken-NJ/13-Lutz-presentation.pdf (I know, this is an Airbus presentation, but...)
PPS) today is Bleriot's 100th anniversary, a man not bothered by autmated systems: Le 25 juillet 1909 .The same flight was performed today

Last edited by Hyperveloce; 25th Jul 2009 at 18:50.
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