Re: Help for new Q-200 pilot/owner


David J. Gall
 

[OFF-LIST]
Geoff,

"I don't see a reason...." <---- That will be your epitaph.

Okay, I'm not very convincing. In that case, I'll start with analysis and
progress right on through to the thrashing. Let the flaming wire-brushing
commence:

Let's see, with 10 knots of wind....

Upwind taxi, 45 kts GS = 55 kts airspeed, almost flying. 90% of the
airplane's weight is not on the wheels, the canard is not flexed much, and
your camber is positive giving good directional stability. The rudder sees
55kts so it is "alive" in case the tailwheel isn't.

Downwind, 45 kts GS = 35 kts airspeed. 80% of the airplane's weight is on
the wheels, the canard is flexed under the load and the camber is neutral or
(heaven forbid!) negative if you haven't done the alignment thing. Your
airplane is directionally unstable and there IS a critical ground speed
above which it WILL become divergent. What is that speed? I dunno, why don't
you get out the flight recorder from when YOU lost control on landing,
because your report is a CLASSIC report of directional divergence due to
instability. Your words:

"So, there I was, careening down the runway, trying to keep the nose pointed
forward. I ended up out of control, and leaving the runway. The wind was
coming slightly from the right, and I overcontrolled as the plane tried to
head to the right. I have a vivid recollection of the plane veering strongly
left, and giving a full right rudder/brake control input as I exited the
runway."

That's CLASSIC! The plane tried to head to the RIGHT, but you ended up
standing on full right rudder and brake because it charged off to the LEFT
at the tiniest corrective input. CLASSIC directional instability.

If it could happen to you on landing roll with a headwind or no wind, it
could surely find you when you're doing high speed taxi practice with a
tailwind. What IS the critical speed of your plane...? Or is it simply
sufficient to CAUTION you that you've been caught on the ground going faster
than the critical speed and you already KNOW how that turns out. It SHOULD
be sufficient, but allow me to attempt to drive the point home:

You don't need me to convince you, Geoff. You have ALL the evidence against
high speed downwind taxi practice that you'll EVER need right there in your
own cranial memory banks. Somebody just has to kick you in the shins once in
a while to make you realize that you're lucky you didn't have to involve
anyone in the insurance or mortuary business in your stupidity.

I'll say it again: NO HIGH SPEED TAXI PRACTICE DOWNWIND, DAMMIT!!! I Want to
have some RESALE value when I build a Q200 and if guys like you keep killing
the airplane's reputation with STOOPID ANTICS against GOOD ADVICE I'm gonna
hafta buy a wire brush and a Tri-Pacer and get old without a Q-bird at all,
like Jimmeh. Yes, that last is aimed SQUARELY at you, Geoff. You've had Jim
Patillo's excellent advice until he was exasperated with you and now you've
got mine. Square up and test fly responsibly before you prang Kittleson's
airplane again.

Your words again: "I don't see a reason not to practice taxiing downwind...
but am willing to be convinced otherwise."

Geoff, if you gotta have your head up your ass, open your eyes and look
around for a brain while you're in there. Yes, that's an open flame because
you've EARNED it. "I don't see a reason...." And you never will when you
blatantly CHOOSE to press your eyes shut evey time somebody tries to show
you the light. "I don't see a reason...." It's not my job to SHOW you a
reason, it is your responsibility to LOOK for one when you CHOOSE to go
against 90 years of commonly accepted wisdom.

I'm not here to try to "convice" you of anything. If my words fail to
persuade you, then I must be the one who is inadequate. Shame on me. "I
don't see a reason...." Bullshit. You're in a taildragger. You DON'T TAXI
FAST DOWNWIND IN A TAILDRAGGER. PERIOD!!!! You don't need the QBA or any of
us here to tell you that, your Citabria instructor told you that on day one
of taildragger school. C'mon, gimme a break Geoff.

"I don't see a reason...." <---- That WILL be your epitaph, Geoff.


David J. Gall
Comm Inst. ASMEL, former CFII, B&AGI, CPC, former ASC, BSAE.
Listen UP!

-----Original Message-----
From: smidude [mailto:smidude@...]
Sent: Tuesday, November 23, 2004 7:31 PM
To: Q-LIST@...
Subject: [Q-LIST] Re: Help for new Q-200 pilot/owner



David,

Thanks for pointing out what could be very hazardous. Yes, I
have a ground speed indicator, in the form of a GPS with a
large numeric ground speed display that I was following. Once
I started accelerating, my eyes were pretty much glued to the
runway, so my estimate of the speeds is based on infrequent
and tentative glances at the display. I agree that taxiing
downwind to an airspeed of 55 kts would be highly
hazardous...I would not suggest taxiing with a ground speed
above 60 kts! I estimate my airspeed was ~45 knots on the
fastest runs (N200AL pitch bobs at 62 kts).

I also agree that high speed taxiing is hazardous.
Accelerating up to near flying speed and then slowing down
felt more "on the edge" than any landing I have done since...
I just could not figure out another way to get the experience
and skill required to land. I advise approaching this type of
taxi work with an abundance of caution and a lot of very
gradual progression.

David, I don't think you have so far made a strong argument
against downwind taxiing. If you are following ground speed,
and staying on the ground, with the reflexor up (ie, tail
down), I don't see a reason not to practice taxiing
downwind... but am willing to be convinced otherwise.

Geoff
---
Geoffrey Rutledge
N200AL Q200

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