Re: NTSB recommend FAA to require installation of AOA system in all transport category aircraft

Date:         24 Oct 97 04:33:15 
From:         s_odle@earthlink.net
Organization: EarthLink Network, Inc.
References:   1 2 3
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On 16 Oct 97 00:44:12 , tschell@s.psych.uiuc.edu (Terry Schell) wrote:

>s_odle@earthlink.net writes:
><snip>
>>Why, is it any easier to fly angle of attack instead of airspeed?
>
>Because the important AOA's (best glide, stall, etc) do not vary with
>gross weight.   Finding best glide using airspeed requires knowing
>your weight at that time and then using a table/computer. Stall is
>even worse because you are very concerned about the effect of turns on
>stall speed. You need to know actual gross weight and then compute the
>force in the turn and *then* look it up in a table to find the stall
>speed.  With an AOA meter you just *look* at it; it will tell you
>exactly how much lift you can extract before a stall.  Any error in
>calculating your weight at that moment will result in blowing both
>computations when flying by airspeed.

It is not nearly as simple (and inexpensive) as everyone would like to
believe.

1)  The pilot would need to know the aircraft configuration  (flaps)
and look at a table to know what AOA to fly to (sound alot like having
to know the weight and looking at a table to know what speed to fly).
Or you would have to have a much more sophisticated (and expensive)
electronic system that keeps track of such things and displays the
correct AOA target to the pilot.

2) Some speeds the pilot flys are not mearly a function of being a
certain percentage above stall speed.

3) What about when tthe wing is contaminated from ice.  Since there
are aircraft that do not have full-time anti-ice/deice systems under
some conditions, the resulting  ice contamination will reduce the AOA
for stall.  Under conditions such as this the AOA system is no better
than airspeed.

There are many things that must be considered.  People make comments
implying that the FAA, ICAO, or whatever, agency they care to talk
about needs to act.  What makes everyone believe they are not? Simply
because the do no react instantly to the NTSB recommendation?

In this country there are laws that specify what the rule-making
process is.  Many people feel the the process takes to long (including
the time to review any NTSB recommendation).  Whats amazes me is that
many people like to complain that the FAA does not follow its own
regulations while others complain when they do.   If you don't like
the process, than get the laws changed, but don't complain when they
follow them.