Peter, I think your absolutely correct in regards to spin testing Lancairs. I don't think anyone is advocating spin testing of their a/c, however in stall testing I think some have departed into spins [asymmetric loss of lift etc]. In general terms, you have to stall to spin so once your doing stall testing, you have less margin for error before your entering a spin. Again, I will iterate that [in my opinion] once flight testing is completed the a/c doesn't NEED to be stalled but can be trained using approach to stall, identification and the appropriate recovery executed. If the flight testing is carried far enough, the stall will be tamed a fair bit and the likelihood of entering an inadvertentspin is that much lower still [ie; installing wing cuffs which can delay the entire wing from stalling at one time].

It is my plan, when the day comes, to use some form of a spin chute while test flying my Lnc2. I still have the ability to plan for it and I've been looking at locations where I could put hard points in the tail cone to mount such a device. In my case it would be just as a 'second to last' solution for recovery from an un-intended spin [only installed] while flight testing. [the 'last resort' solution would be a personal chute].

There are lots of certified planes that are not approved for spins, that isn't anything unusual. It's not to say that they can't be recovered or haven't been flight tested for spins/spin recover [I'm taking certified a/c].The fact that they have been placarded against it for some reason [there are lots of reasons other than structural or aerodynamic] is not concerning and it isn't concerning to me that Lancairs shouldn't be spun. However, every certified a/c on the market has been stall tested.. every last one of them..  The Lancair is by far the exception to the rule by comparison. For some reason it's become the normal way of thinking to change the view on this type of training and testing while flying this airframe. Some would say that this level of flight testing is fine for certified a/c [after all they have higher standards] and doesn't apply to experimental a/c. While in some form I can appreciate this argument, we all like to compare these planes to what we'd be 'forced' to fly if we went the certified route, so we're already comparing them to certified a/c but only in a light which favors the performance we want to talk about [TAS, Climb rate, cost etc] who brags about the 'not so steller' record that the Lancair airframes boast? I doubt there are very many people bragging about that!

Why not approach the flight testing and training in the same way as the certified crowd? Why not flight test these birds and ensure they fly better than the certified a/c in every way, including stall and stall recover [again spins are not part of this 'normal use envelop']. Then we KNOW we have a better aircraft than can be bought off the show room floor and that it's better in every way.

What makes the Lancair so special to be allowed exclusion from the same type of testing and training vs every other form of Business, Commercial and GA aviation?? I'll never understand it. As terrible as it is to say it, I think we're going to continue to see these types of accidents continue to happen until this mindset changes. There isn't a simple [probably not even cheap either] solution to this problem. As my father would say, "pulling an 'osterich' " isn't going to solve it either. [in my opinion]

Btw, my perspective isn't to lessen the efforts of those who advocate getting further training. I applaud the efforts of Jeff and the LOBO. There is a lot of work that has been done behind the scenes and it's greatly appreciated.

Fwiw

Jarrett Johnson

235/320 55% [and holding]

 

On Mon, 07 Jan 2013 13:25:38 -0500, marv@lancair.net wrote:

Posted for "Peter Field" <pfield.avn@gmail.com>:

Dear Lancair Drivers:



I've been following the discussion on stalls and spins and I want to add
some additional factual information purely for your personal consumption and
reflection.  Attached are excerpts from 10 different 1980-90 NASA flight
test final reports on a series of GA airplanes in which NASA evaluated the
use of cuffs on leading edges to improve the behavior of the test airplane
approaching the stall.  For various reasons the cuffs improved lateral
control entering the stall, but had the adverse effect of destabilizing the
aircraft once a fully developed spin was achieved.  Essentially, stall
behavior was improved at the sacrifice of spin recovery.  Cuffs on wing
leading edges are an add on design fix, the more elegant solution is
"washout," where the wing is twisted so the outer portions of the wing
always operate at a lower angle of attack.



To my knowledge, Lancair has never subjected any of their aircraft to a
fully developed spin matrix complete with appropriate instrumentation and a
spin recovery chute.  There is no FAA requirement for them to do so - it's
an Experimental Category airplane.  Early on they may have lightly touched
on such testing; but I have never seen any documentation on a fully
completed spin matrix, which would involve at least 160 spins at various
cg's and lateral loadings.  In my opinion, it would be highly risky to fool
around much beyond the stall in any Lancair - there is no documentation that
indicates any of these airplanes can always be recovered from a one turn
incipient phase spin or any fully developed spin.  Being good at spin
recovery isn't so much a matter of how skillful a pilot you are, it's a
matter of how many spins you've experienced in airplanes known to be
recoverable.  Being familiar with the stall characteristics of your own
airplane should be a matter of personal preference.  



Best regards,

Pete Field (LNC2)

USNTPS graduate & spin recovery instructor

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