Re: taxi test exit criteria


Doug Humble <hawkidoug@...>
 

Wes - IMHI - I think you should taxi test the way you would for your first flight. I mean set your reflexor & CG the way you plan to for your first flight. I believe what you should do is give yourself confidence in your abilities to fly this aircraft. One set up is fine for this. Practice so you will be successful for one set of conditions. You can expand the window later. In your mind you have read and heard a lot of things about how this aircraft handles, but until you have done it, they are other peoples experiences. I picked "perfect days" to taxi and fly my first few flights in order to gain confidence in my abilities to fly the airplane. Once this became "somewhat mondane" I then opened up the window on some of the items you mentioned. I'm still not done as I opened the window a little to far on my last flight!

Taxi till it is boring and then taxi some more. (where did I hear this from) Then you will be ready. Then pick a calm day and go fly!

You are lucky to have Q flyers around you to help. Do what they say!

Doug "Hawkeye" Humble
A Sign Above www.asignabove.net
Omaha NE
N25974

----- Original Message -----
From: wesisberg
To: Q-LIST@...
Sent: Thursday, October 05, 2006 11:48 PM
Subject: [Q-LIST] taxi test exit criteria


Hi -

(Ok, third message to the group today - and sorry about the fionapple
alias)

What exactly should I find before calling taxi testing successful? I
hope to be able to finish in a week or two (having done about ten
hours in the last two months).

Under optimum conditions (reflexor full aft, mid-CG) I'm able to
maintain reasonable control using tailwheel, brakes, and/or ailerons
up to 65 mph ground and air speed (not yet testing past that pending
more serious first-flight prep). But how far should I go in testing
further configurations or speeds?

E.g., Brian Martinez wrote that his tailwheel stayed down at 60 mph
with neutral reflexor. Should I expect that? How about when I'm at
the forward CG range? What crosswind component should I try?
Obviously there are a number of parameters:

- ground speed, air speed, crosswind speed
- weight, CG, reflexor
- power and brakes, abruptness of application

I'd like to target any condition I'm likely to find myself in and any
situation where folks have found unanticipated behavior in their
planes. I think that includes an 8-knot crosswind, tanks close to
empty (light, forward CG), little to no headwind (i.e., fastest ground
speed), and fully loaded with little headwind (i.e., more mass to push
the wheels around). Does that cover things?

I'm also interested in targetted tests. E.g., for the reflexor I'm
considering taxiing with forward CG and the reflexor forward,
increasing speed very gradually just to the point where the tail/plane
gets light, to find out the actual difference in lift and tailwheel
purchase due to the reflexor. (Same for neutral reflexor.) For
aborts/go-around's, I've been doing abrupt power tests to see how the
plane responds. I've also tested some high-speed turns to find out
how much energy I can expect to lose and whether there are any
gotcha's. Does anyone test for oscillations? There's enough of a
bump in the runway to induce oscillation; should I avoid or try that?
(I've staticly tested the wheel alignment change when bouncing but
need to redo that under load.) It might help to know that my plane is
relatively light and has upswept main wingtips. I'm pretty sure it
would nose over if I went full power with forward CG at run-up. I
plan a series of nose-over tests at various weights once I get someone
to hold down the tail for me.

Obviously I'll prepare for, and plan to avoid, inadvertent first flight.

Thanks -
Wes

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