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Old 26th Jul 2014, 00:42
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PerAsperaAdAstra
 
Join Date: Jul 2014
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I was wondering if you could clarify a bit what you meant by "...why does the computer air data program attach quite so much importance to pitot static airspeed?".

What I meant here was as I recall when the airspeed data corrupted, the aircraft went into alternate law mode, which seems to have added to the crew confusion, yes you are right about the stab trimming nose up due to the sidestick input, but I understood this trimming happened automatically under the "alternate law", recovering from a stall with full up stab trim would vastly confuse things.

This is what I meant by "so much importance to IAS", to me it seems there should be more parameters measured, before he system reverts to alternate law? For example shock stall and crit alpha stall cause the same symptoms as such (buffet), and with a falty IAS reading in IMC, the only sure way to tell the difference is AoA? If the crew had had this, would they have realised they were at low speed, not overspeed?

This may have been discussed earlier, but this was a very interesting accident (very tragic too), as it touches on the clash between classic stick and rudder skills, and modern aircraft AP systems.

(By the way, how do you do a quote on a forum post? I looked in FAQ but no luck? I am anashamedly a very pre computer ager, when I joined the air force, the most odern piece of kit on the Sqn was a hand cranked copier!)
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