PPRuNe Forums - View Single Post - AF447 Thread No. 3
View Single Post
Old 9th Jun 2011, 21:03
  #1700 (permalink)  
JD-EE
 
Join Date: Jun 2009
Location: I am where I am and that's all where I am.
Posts: 660
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Lonewolf_50
Heh. Given that landing speeds of most transport category aircraft are well in excess of 60 knots (A330 looks to be 135-145kts, depending on weight and other conditions) an aircraft in that class with a stall warning at 60 kts below 1000 feet has been in deep manure for too many seconds, and has most likely been gettting stall warnings since long before that ...

Which makes me understand why clipping it at sixty might seem to make sense in the design process, but that seems to indicate a design assumption:

That stall will be triggered at low speed and low altitude? (I may not have successfully reverse engineered the thought process on that one ... )
That's why I'd NOT turn off the stall warning of there is no weight on the wheels. I'd add an altitude test if there's a reliability problem with only using weight on wheels.

Then it may be wise to enter the inertial reference's output into the equations at least for short term stall warnings. Then maybe train in a 10 second or 15 second wait before acting on stall warnings at cruise altitudes.
JD-EE is offline