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Old 27th Jun 2009, 19:47
  #2422 (permalink)  
jcarlosgon
 
Join Date: Mar 2008
Location: At home, retired 2012
Age: 75
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stepwilk
Well, somebody finally said what I've been wondering for 123 pages of posts. Back in the Dark Ages when I learned to fly (mid-1960s), we were taught that what you did if you flew into Cunim was 1/maintain attitude and wings-level, 2/hold pretty much the power you've got, and 3/ignore altitude. Nobody ever said much about airspeed, which took care of itself if you did 1, 2 and 3.


That is absolutely true and it will stay that way… but…
It is very difficult to perform step #1 in alternate law, as the “protection” against too low or too high speed – be it erroneous or not, will demand a considerable permanent force on the stick, until the computers, not the pilots, switch to direct law.
Quote, FCOM, my underlining,
PROTECTIONS
Low speed stability
At low speed, a nose down demand is introduced in reference to IAS, instead of angle of attack, and alternate law changes to direct law.
It is available, whatever the slatslflaps configuration, and it is active from about 5 knots up to about 10 knots above the stall warning speed, depending on the aircraft's weight and slatslflaps configuration.
A gentle progressive nose down signal is introduced, which tends to keep the speed from falling below these values. The pilot can override this demand.)

I wish I had a DDL (Directly to Dorect Law) Switch (not a push button).
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