Mailing List lml@lancaironline.net Message #35541
From: terrence o'neill <troneill@charter.net>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] AOA
Date: Fri, 28 Apr 2006 21:26:58 -0400
To: <lml@lancaironline.net>
John,
    Im's so old I carrier-qualified in SNJ-7s in 1954 on the USS Monterrey, controlled by watching the LSO's paddles, and before AOAs, which came in three years later, the year I got out.  The Navy didn't know about or teach AOAs or the meatball back then, but also a lot of guys in the fleet were flying into the fantail or stalling and falling into the water... because carrier approach speeds had gone from 90 knots to 130 knots, and there wasn't time for the LSO and pilot -- when they were close enough to each other to see LSO signals, to communicate the condition of the plane flying so close to stall AOA.  The Brits invented the AOA-fresnel system we adopted in 1956 , and have used for 40 years,  to this day... as you know... with wonderful, life-saving instant results... cutting landing crashed 50% the very first year, and we're talking very professional, top-quality trained pilots here.
 
    I have to point out a few things in your comments, if you don't mind.  Maybe you haven't thought about them in just this way. Keep your mind open, so you can consider shifting your attitude a little.  What you say is true, but I think -- incomplete.  You're talking about avoiding danger.  I'm talking about getting out of situations that are already BAD.
 
    I spent a lot of time many years ago reading  800 NTSB accident reports involving GenAv with fatalities that covered  a 14 year period, and I also referenced Navy publications on the subject.  No commercial or military fatalities, or helicopter accidents were included in my study.   I evaluated, then analyzed the results, and wrote an 8-page article for Kitplanes Magazine published in December, 1998.  The Kitplanes editor then was Dave Martin, who had hundreds of traps as a back-seater in F4s, and loved the article.
    I found the NTSB is not at all uniform in analyzing or labelling the CAUSE of a fatal accidents.  They still are not.  So for my study I first defined a uniform fatal-accident-'cause' as: the last thing that happens before a pilot loses control or crashes into something.  Thus, engine failure is not a 'cause', because he could still glide and land with no fatality.  But inadvertant stalling, or spinning and unable to recover before flying into something, or a wing coming off a P210, I label a 'cause'..  Etc. Okay?  .
    That agreed to, then I found that for the 14 years prior to my 1998 study, 28% of all general aviation type-certified airplanes 5222 fatal accidents were caused by unintentional stalls.  Twenty-eight percent!   In the same time frame, among Experimental amateur-builts' 701 fatal accidents, 45.3% or 318 were caused by unintentional stalls.  Forty-five percen t!  These rates had remained practically unchanged during the 14 years covered by the reports I analyzed. 
   
You said:
     The airspeed indicator was neither accurate enough nor quick enough to handle these kinds of approaches.  There simply is no reason for any experienced civilian pilot to get anywhere near stall speed low except in a flare over the runway and therefore no need for the kind of precision and quick response afforded by an AOA.

    That's true.  Bujt your phrase '...there is simply no reason ...' is the -- incomplete consideration here.  Accidents don't happen because someone's doing something 'reasonable'; but often quite the opposite.  Or, a
s the bumper sticker says "Shit happens!" --- usually when you're concentrating on something else, or just having a good time, or you are confronting a vacuum-system failure and a vomiting backseater, a 'revolting development', a Jimmy Durante used to say.  Then what?
    THEN, you NEED to see how close you can fly your wing to its stall angle, without stalling it, because you don't want to hit the damn trees, or whatever...right?  
    Without an AOA VANE (not lights or horns), you're SOL.  You're BLIND! 
    With an AOA vane, you can fly your wing ONE DEGREE below its stall AOA, all afternoon long, NOT stall your wing, not hit the trees, make it back to the runway.
 
Then you also note, correctly but incompletely --
 ... non-military pilots have a problem with understanding aircraft performance at high angles of bank and high g loadings.  We get the idea of how to avoid 1g stalls in the pattern fairly quickly but I see report after report of experienced pilots stalling out while pulling high g's low or trying to get to a runway after an engine failure by doing a very steep turn and not understanding what happens to sink rate if you do that.
 
True.  But it's not 'sink rate'.  It's AOA.  The wing stalls at a fixed AOA, no matter what the Gs or bank angle.  These folks are stalling out because they're AIR-BLIND ... they can  not SEE that they themselves are pulling their wing's AOA right past it's stall AOA.  When they do that, they're committing unintentional-suicide, because they are giving away control!  Because they have no AOA vane, to SEE exactly how far they can go ... how much lift they can tap into..
I have been flying with an AOA since 1964, and oh, what a relief it is.  I can bank as steeply as I want, anywhere, while watching the AOA, so I do not pull the wing to its stall angle. 
After four years flying in the Navy i though i knew a lot about how an airplane works.   Then I bought the last Waco TC project and restored it, and began flight-testing ... and realized I needed to know what was going on with the wing in different tests.  So I made myself a simple AOA vane, like Orville and Wilbur's thread, and put it on the left wing, in my field of vision, and -- was soon saying to myself "I didn't realize that!"
 
For example, I realized that if the wing is pitch-trimmed about it's aerodynamic center --- usually about 25% MAC -- and you initiate a climb or a glide and release the controls, it will; not stall.  It may zoom or dive but the pitch trim sets the wing's AOA, and holds the trimmed AOA.  Most planes will not trim the AOA up to the wing's stall AOA...  so it's the PILOT who causes a stall, by pulling the wing up past its stall AOA.
I remember the  joy of realizing that that afternoon, and then flying my old Waco around for 45 minutes, one degree befow its stall AOA, climbing, zooming, making 90-degree banks, and pulling Gs or zero Gs... and never stalling!
 
So I wrote articles for Sport Aviation, and magazines, and even made some AOAs and sold them... and for 20+ years have been trying to get this basic, simple knowledge to other pilots.  But 99% of them -- syllabus-trained -- don't get it.  They just don't get it!  A few ultralight guys love the AOAs, (not trained wrong by FAA guidelines?) and a couple of airline pilots told me they're trying to get their bosses to put AOAs into their planes, but most folks fly by rote, by habits they learned at the beginning.  Airspeedairspeedairspeed.  It is just -- pathetic, to see good people, people I like, kill themselves, and leave their devastated loving family and friends behind.
 
Can anyone tell me how to force the FAA to REQUIRE GenAv aircraft, old and new, to put AOA VANES ... the most BASIC of all flight instruments of AIR-PLANES ... vehicles that 'plane' their wings at angles through the air, to lift themselves up... not going to too high a 'stall' AOA ...???  Or, how to communicate and demonstrate the life-saving safety this simple device, that anyone can make, that it should be on every air-plane?
 
The FAA could buy and give away and pay to have glued on every GenAv's wing an AOA, for pennies, what they blow on 'safety' every year ... and cut fatalities 25% the first year!  Back in the 1960s I wrote Najeeb Halaby, then FAA director, and he referred me to the FAA's petulant head safety guy ... who was incensed that the suggestion came from the  top-down to him ... and that was the end of that.
 
So, if you -- like me -- think you know how airplanes really work, I challenge you to put an AOA vane on your left wing and go up and play with it.
Not only willit tell you what your fixed stall angle is, but it will tell you exactly how much you have to pitch the AOA DOWN, to unstall it, with minimum altitude loss!
Opinions and comments are invited.
Terrence O'Neill
L235/320 N211AL
 
 
 
 
 


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