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Tom,
Good points. I hope you see my other posts that allude to this as well.
I agree that the "desirability" of various handling characteristics is
completely subjective. What I am asserting is that the rating or value of
those characteristics are not - they are objective.
I happen to know the director of test flying for the Grumman Yankee, who
quite because - due to time constraints and investor pressure - they kept
coming up with bandages and wouldn't (couldn't?) properly fix the plane
before it was introduced. Obviously, the FAA certified it, but one only has
to look at the record to know that the plane had problems. Can a good pilot
still fly it? Of course. Can a good pilot learn to enjoy the given handling
characteristics of the plane? Again, yes.
Nonetheless, that does not make the plane stable or unstable. How many times
do I have to say it? Stability and control issues are mathematically
determined by calculating the derivatives. Those numbers do not change. The
only thing that is subjective is what the designer or pilots consider
acceptable.
What I am addressing is not "which plane is the most fun to fly?" That is
completely subjective, even without taking into consideration the different
mission profiles. I have several acquaintances who have had the privilege of
flying many types of planes. One would invariably say that flying a P51 is
the most fun he has ever had. On the other hand, he would also that the J-3
is the funnest plane to enjoy the "essence" of flying. Nor would he enjoy
flying anything off the water that wasn't a DeHaviland... This is one pilot
- who can't even make up his own mind! If we can't even exorcize all (but
one?) of the demons that plague this one pilot, how in the world can we get
any arbitrary group of pilots to agree? For goodness sake, you can't even
get a quorum on which Lancair is the best!
All that to say, I wish I could afford to be like Jay Leno and all his
cars... I wish I could justify a dozen different planes, all for different
reasons (and I have yet to meet a pilot that doesn't want at least three).
But as I'm sure you'd agree, there are way more planes that would never get
on our list, even if they were given to us. For you, it might be a 172. For
the Cessna drivers, it might be the Grumman. But to claim that they never
convinced you it was unstable is a bit naive... Did they ever show you the
stability numbers? Have you ever seen them? For that matter, have you ever
seen them for the Grumman?
I do not argue that you have the right to prefer, ask for, or fly a plane
with different stability and control numbers than any/every other plane.
What I do ask for is that you - and every other pilot - agree that we
compare known objective numbers.
I don't care what golf clubs you use or what balls you hit - some things
work better for some and not for others. But if you can put a golf ball in
some sort of testing apparatus, and determine which one flies farther,
higher, straighter, etc., you should then be able to have something to stake
a claim on.
I have been accused of not stating the facts, and offering nothing but
rhetoric. As if to say, just because I don't know the facts (derivatives)
about the Lancair that talking about derivatives should have no bearing on
the conversation (debate?). Such an assertion would be ludicrous. Though I
don't doubt you have much more fun in a Grumman than a Cessna, that really
isn't the point. However, you do get close by talking about the Legacy
having "better hands off stability than most certified planes I've flown."
Though that is still subjective, it gets close to where I am asking you all
to look. The next comment about it taking " a light touch to fly one
smoothly" is maybe more meaningful. After all, it is a rather
straightforward thing to change the control geometry such that there is more
movement needed to create the same amount of deflection (which brings up the
limitation of side sticks and some center sticks). But if by "light touch"
you mean that it is hard to dampen or stabilize the plane, because pilot
inputs are difficult to control - I would label that as "touchy" or
"twitchy" - both subjective terms. Regardless, there are actually "numbers"
for these variables that - glory be - can actually be "objectively" compared
to those of other aircraft.
Let me repeat: I do not claim that there are a certain set of "correct"
derivatives - to each their own. What I do claim is that such numbers can be
fairly compared to each other, and various aircraft can be ranked relative
to each other. It is up to the individual pilot to determine what they can
fly comfortably, let alone safely. In an ideal world, there would be as many
aircraft models as there are car models, so that each of us could have more
to choose from, to tailor to our particular wants, needs, and abilities.
As has already been proven by Glassair, Lancair, Compare, etc., many pilots
would gladly give up their certified aircraft for planes with better
performance at the same price. I suspect that many/most pilots would also
gladly consider trading their current plane for one with similar performance
and price if it were easier or safer to fly. Frankly, we are betting on it
with the Envoy. As I said in my previous post, Lancair might double their
market if they did the same. Eventually, someone will... I just suggest that
Lancair beat them to the punch.
RA
-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Tom
Gourley
Sent: Saturday, May 20, 2006 4:11 AM
To: Lancair Mailing List
Subject: [LML] Re: IVP Crash
Rienk Ayers wrote:
> Though I have flown an L4 and Columbia with the idea of buying one at
> different times, I do not have even an hour in each type, so I have no
> way to judge or compare the different models, let alone discern the
> stability and control nuances - I just knew they were too twitchy for
> me.
"Twitchy" is a highly subjective evaluation. I learned to fly in a Grumman
AA-1B, a plane that evolved from the 2-seat American Yankee. Since it was
the first airplane I ever flew, and the one in which I developed my flying
habits and reflexes, I had no problems with it. Pilots who learned to fly
in 150s didn't like the little Grumman. Most of them complained it was
twitchy and unstable. I loved it. It was light on the controls and very
responsive. The first time I flew a Cessna 172 I thought it felt like a
truck; a very unresponsive truck. I've yet to fly in a an ES or LIV, but I
do have a little stick time in a Legacy. To me it's not at all unstable. It
is responsive and precise but has better hands off stablity than most
certified airplanes I have flown. It does requires a light touch to fly one
smoothly.
If you feel an airplane is "twitchy" then don't fly it. On the other hand
don't try to convince pilots whose likes and dislikes are different from
yours that there is something inherently wrong with their airplane of
choice. The Cessna drivers never convinced me that the Grumman was
unstable, and I never convinced them that Cessnas are trucks.
Tom Gourley
Legacy Builder
----- Original Message -----
From: "Marvin Kaye" <marv@lancaironline.net>
To: "Lancair Mailing List" <lml@lancaironline.net>
Sent: Friday, May 19, 2006 4:45 AM
Subject: [LML] Re: IVP Crash
> Posted for "Rienk Ayers" <rienk.ayers@sreyaaviation.com>:
>
> Jeff,
> you are probably right about the Lancairs in question being the older
> two seat variants. Again, I was just quoting him, and I gave a good
> enough reference that anyone could read the whole article themselves.
> Though I have flown an L4 and Columbia with the idea of buying one at
> different times, I do not have even an hour in each type, so I have no
> way to judge or compare the different models, let alone discern the
> stability and control nuances - I just knew they were too twitchy for
> me. Only a qualified engineer could legitimately compare the numbers
> (derivatives) or
> an unbiased test pilot be able to discern the differences. My opinions
> are
> based upon feedback from qualified people, including professional
> engineers
> and test pilots who have flown the Lancairs - and that is as much as I'm
> going to say about that.
> My level of expertise has nothing to do with this issue - the numbers
> speak
> for themselves. I have yet to hear from a Lancair builder/pilot who even
> knows what derivatives are, let alone what they mean, and what the
> numbers
> actually are for any model of Lancair. To be fair, I sincerely doubt that
> most designers and manufacturers even know either. But if I were an
> owner/builder, I would sure hope that someone could give me the answers -
> at
> least the theoretical numbers that were calculated in the design process
> (only wind tunnel testing can completely verify them). don't inquiring
> minds
> want to know?
> Yes, you could simply say that you've flown an airplane, you can live
> with
> it's bad characteristics (if any), and make sure you don't "fall of the
> wall."
> But if you will recall, this thread got started when Allen Adamson
> wondered,
> "what can be done to create a safer lancair record."
> My suggestion? Don't just teach gymnastics - rather, shorten the wall.
> RA
>
> --
> For archives and unsub http://mail.lancaironline.net/lists/lml/
>
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