Message-ID: <37A87F6F.BFAF5A38@swbell.net>
Date: Wed, 04 Aug 1999 12:59:11 -0500
From: Greg Nelson <gregsays@swbell.net>
Organization: Southwestern Bell Internet Services
To: lancair.list@olsusa.com
Subject: First flight and weight and balance
Mime-Version: 1.0

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N95EG flew for the first time on 22 July 99 and now has 13 hours total

flight time.  This aircraft has a small tail, extended wings, 180 Lycoming,

Airflow Performance fuel injection, Ivoprop Magnum propeller and is being

flown in a primer coat.


With pilot and low fuel this aircraft fairly explodes off the ground and

easily sustains a 2500 feet per minute climb and has no unhealthy flight

characteristics whatsoever.  I listened to you and then wisely obtained five

hours of flight instruction in the company's Lancair 360 at Redmond, Oregon

before my first flight in N95EG.  I can say confidently, that had I not

obtained this flight instruction, I would have crashed or damaged my

aircraft on initial test flight.  While not at all quirky, this airplane has

some different flying characteristics for which  other high-performance

airplanes that I have flown did not prepare me.  I powerfully recommend that

each Lancair builder get flight training from Redmond prior to test flying

his own airplane.


In opening the flight envelope of this airplane, I have quite gradually

increased the gross weight of the airplane which necessarily involves

progressively moving weight to the rear of the airplane and into the baggage

compartment.  In doing so, I am now at just 60 pounds below the published

maximum gross weight of the airplane.  With only 10 pounds of baggage in the

baggage compartment and 175 pounds allocated to passenger, the airplane

bobbles (oscillates) uncomfortably even at higher speeds if the stick is

excited.  Of course, it flies straight and true if I attempt to avoid

oscillation but straight and true is not always possible when in turbulence

or sudden changes of altitude/attitude are necessary (as in flap

deployment).  I believe that this may be due to an aft cg.


Yes, I have carefully calculated the necessary position changes of battery,

hydraulic power pack, etc., called for by reason of using a lightweight

composite prop and indeed, I can think of several more changes that I can

and will use to effect a more forward cg.  I guess I am most concerned that

the cg measurement by scale may not have rendered accurate cg information.


This should be of concern to other builders as well because my weight and

balance figures COMPARE FAVORABLY with the others that have been published

on this web site.  I used three commercial (non-spring) scales that appeared

to be very sensitive and well calibrated and their weight measurement ranges

each ran from zero to 1000 pounds.  I did the entire weight and balance

routine carefully and twice, partly because I didn't trust the figures of my

first measurement.  For instance, in adding weight to the airplane as it was

sitting on scales, the weight actually added would not be exactly equal to

the measured increases reflected on scales, i.e., adding 10 pounds to the

baggage area would result in a 1 1/2  pound increase in one scale and a 3

lb. increase in another scale with no increase in the third.  A subsequent

addition of 10 pounds might result in an increase of 12 pounds total

(vibrating the aircraft on the scales did little to correct this problem).

Interpolation was necessary to make sense of the weight and balance

measurements.  In short, the scales I used did not render completely

accurate information; information that is so essential to safety.


Have any of you had similar experience in your weight and balance

exercise?   How did you proceed?             Greg Nelson


[Congrats on that successful first flight and your careful approach to

flight testing.  I'm excited to see that you've chosen the Ivoprop Magnum

and am anxious to hear more about how you feel about it.  Can we assume

that it is the in-flight adjustable version, and if so could you share

some more particulars, such as installed weight, pitch range, etc?

What with the high cost of the typically used Hartzell and MT props it

will be interesting to follow the progress of this installation to

see how it performs for you.


I hope that you get the W&B issues nailed down to your satisfaction...

I suspect the use of a different set of scales that accurately reflect

changes as they are made should simplify things immensely.


Please keep us informed as to your progress and enjoy your new baby.  I'm

pleased to learn that the input you received from the LML was beneficial

in making that long voyage into the sky a reality for you.  Congratulations

once again.


      <Marv>     ] 

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