In a message dated 8/8/2006 12:00:09 A.M. Pacific Standard Time,
europa-list@matronics.com writes:
From: "nigel charles" <nwcmc@tiscali.co.uk>
Subject: RE: Europa-List: Stalls and spins
It is important to realise with all stall warning systems whether they
are giving you warnings above a nominated speed or whether they are
giving you a warning that you are approaching a critical AOA.
For example 5kts warning above a critical AOA is better than 15kts
warning above a speed which is the wings level one 'g' stall speed. If
you bank 45deg in level flight the stall speed increases by about 40 per
cent so if your wings level stall speed was 40kts at 45deg bank it
becomes about 56kts. Thus in this case a speed warning of 15kts before
the stall becomes no warning at all whereas a conventional stall warner
or AOA system will still provide the 5kt warning
Nigel Charles
Nigel,
Excellent comments, This is exactly why I produce an AOA system, an AOA is
correct under ALL conditions, it will warn you of the AOA, in our instrument
an audio announcement will advise when about 5% under the minimum approach
speed. Stall warning devices are like closing the door after the cows are out.
To late with to little. An AOA will give proper warning when a trend is
apparent, warning 5 or so below the min approach speed, then the stall warning
5
above the stall. In the US the stall warning certification has one
stipulation ~~ be at least 5 Kts above stall. I've flown some aircraft where
the
stall warning is coming on at 20 above the stall, the owners totally ignore it,
then get into another aircraft and wham~~ enough said.
Elbie
EM Aviation
_www.riteangle.com_ (http://www.riteangle.com)
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