Sender: <marv@lancaironline.net> (Marvin Kaye)
To: lml
Date: Mon, 24 Jun 2002 19:28:04 -0400
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 originator="Paul Davis <pdavis@pdavis.bmc.com>"
From: "Paul Davis" <pdavis@bmc.com>
Reply-to: "Paul Davis" <pdavis@bmc.com>
Subject: Re: [LML] Re: stalls 
In-Reply-To: Your message of "Mon, 24 Jun 2002 16:22:10 EDT."
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>>>>> On Mon, 24 Jun 2002, "JPKleber" == JPKleber@aol.com wrote:

  JPKleber> Less/No stall practice/training = less proficiency in
  JPKleber> stall recognition/recovery = more fatal accidents = more
  JPKleber> insurance claims = higher insurance rates for all of us!

This attitude seems so reasonable, so logical.
It's satisfying and just feels "right".
How could any reasonable person argue against it?
I used to share this belief.

But it rests on two unproved assumptions:

  1.  Stall (and spin?) training reduces the incidence of stall/spin
  accidents or improves outcomes.

  2.  Intentional stalls are unlikely to result in unintentional spins
  in these aircraft and/or such spins are usually recoverable and
  recoverable within some "reasonable" altitude above which we may
  safely stall our aircraft.

If the first assumption were true, then there SHOULD have been few
pilots with extensive stall/spin experience among those who crashed
airplanes due to unintentional stalls/spins.  Reasonable or not,
logical or not, counter-intuitive or not, like it or not, the high
percentage of such pilots in the accident database certainly seems to
invalidate at least the first of those unproved assumptions.

And inevitably some folks are going to get into trouble and crash
airplanes while undertaking training (that apparently does them no
good anyway).  In other words, stall training in these aircraft could
well result in MORE fatal accidents and HIGHER insurance rates.

  JPKleber> An aircraft which has demonstrated poor spin recovery
  JPKleber> should have a placard prominently displayed in the cockpit
  JPKleber> which reads:  "NO SPINS" Same is true for stalls.

I'd almost agree with that, except I'd change "demonstrated poor" to
"no demonstrated good".  Instead of avoiding a maneuver only after
it has been demonstrated to be dangerous, I'm inclined to avoid it
until it has been demonstrated to be safe.

We don't KNOW what the spin recovery is.  We don't even know that
all spins are recoverable (certainly not with full flaps and a dead
engine).

We don't KNOW the likelihood of unintentional spins from
(unintentional OR intentional) stalls.

So we don't KNOW whether that second assumption is true -- or not.

And THAT is the problem I have with stall training in the Lancairs.

As I think I said in my first post on this subject:
Absent a spin chute I'm not eager to stall these aircraft.
I simply don't know how to assess the risk.  I have no way of knowing
when or if a simple, intentional stall might suddenly become an
unintentional spin that might not be recoverable.

If a case -- not based on conjecture -- could be made that this is
reasonably safe AND worthwhile, I'd stall the heck out of it.  But the
sited article seems to reinforce my suspicion that all the stall/spin
training in the world is of no real benefit in preventing stall/spin
accidents.

So why take an unknown risk for questionable benefit?

-------------------
Paul Davis
Lancair Legacy builder
pdavis@bmc.com
Phone 713-918-1550
-------------------
Anyone can see a forest fire; skill lies in smelling the first smoke.
--Ira Weatheral, Time Enough For Love, pg 47