While I do agree with your premise that the Europa should be built light and
minus unnecessary complexity, I beg to differ on you conclusion regarding
AOA. An electro-pneumatic AOA such as from Proprietary Software Systems
weighs about the same amount as the average pilot's body weight changes
during the day, and has the complexity of a few LEDs in a line on the panel
and a small electronics box located out of sight and drawing very little
power. In exchange for minimal weight and complexity the pilot will know
almost exactly how close to the critical angle of attack the wing is flying
for any combination of gross weight, CG location, and load factor.
Indicated airspeed and conventional stall warning devices give no such
indication, merely telling us that if we fly at not less than certain
minimum airspeeds we will probably not stall. Probably, not certainly.
For us AOA is of no use at cruise but it is very useful at low airspeed,
especially in the pattern/circuit. Anyone not convinced should peruse, for
example, http://www.monmouth.com/~jsd/how/htm/aoa.html and
http://www.boeing.com/commercial/aeromagazine/aero_12/attack.html
Best regards,
Rob Housman
A070
-----Original Message-----
Behalf Of Alan D Stewart
Subject: Re: Angle of Attack indicators
I'd like to say that I personally agree with a previous posting on this
subject.
I'm certainly not saying mistakes don't happen, and I acknowledge that
if builders want to add
more and more accessories, particularly with safety in mind, then that's
their perogative.
The Europa I believe, falls into a category of aircraft which should be
built light, and VFR flying should as straightforward as possible.
I think that there's a trade off between warning mechanisms, complexity,
weight and safety.
There is a well accepted statistical theory called 'risk compensation'
which, when applied to the highway, accounts for the propensity of road
drivers to take greater risks when presented with increased safety
measures introduced by car manufacturers.
Sometimes I wonder if having a extra safety system installed may make me
complacent enough to overlook simple visual checks and neglect basic
pilot skills ?
Alan
-----Original Message-----
From: forum-owner@europaclub.org.uk
Subject: Re: Angle of Attack indicators
Folks,
Trigear GOURO
I have the RMI instrument which as well as giving Rate of climb, TAS,
CAS,
Alt alarms and all kinds of other things also gives low airspeed speed
alarms. I have found it to be more than adequate and tends only to alarm
in
the very last part of the flair, by which time the rear wheels are about
touching the ground and only once or twice on rotate if I pull it off
too
early. (only did it to try it you understand, I never pull the plane off
the
floor unless I am "OVER" 55 knots)
I don't have stall strips fitted and cant get my head around fitting
some
when it feels fine as it is. With greatest respect I watch my speed
like a
hawk as I know it keeps me alive. Do too many warning systems offer us a
false sense of security and offer us the opportunity to relax our
piloting
skills when we need them?
Regards
Kev T
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