X-Mozilla-Keys:                                                                                 
Ed Anderson wrote:

As one of the honorables that Paul was referring to about the "Weighty"
problem of auto conversions, I would like to point out that while FWF weight
is an important consideration, it is the total aircraft weight that the
power pulls.

My aircraft weight approx 100 lbs more than the average of make and model at
1170 lbs.  However, I have seen numerous completion reports in Vans RVator
mag that reported RV lycoming installations weights over 1150 lbs and a few
over 1200lb empty.  So weight can creep in many places like a full IFR panel
adds approx 20 30 lbs with gyros, vacuum pumps,  marker beacon/glideslope
receivers, dual radios, etc. Throw in an extra 25 AH battery and your have
added another 22 lbs, put a little foam insulation to keep the tin can from
oil canning too much and you probably have another 5 -10 lbs.  You  get my
drift.

However, IF light weight is your foremost design goal then there is no doubt
in my mind that the rotary will clearly beat any comparible HP aircraft
engine even with radiators.   Eliminate any AN/Stainless steel braided
hoses, forget the extra battery that will carry you systems for 1/2 hour
after the alternator fails, eliminate any redundancy in your electrical
system wiring and design,  carry only the bear minimum coolant and oil, etc.
Drop the vacuum pump/airpump.  Get custom made radiators that are lighter
(and more expensive) than the air conditioning cores, etc. Minimize motor
mount tolerances to the bear minimum. etc.

    My point is that any design is dependent on its objectives, the risk
tolerance of the builder and the depth of his pocketbook. Being somewhat
attached to my butt, I made a number of decisions based soley on what met my
risk tolerance (less likely to fail or fail gracefull).  The more risk you
are prepared to accept the lighter your aircraft and engine installation can
be. However, I may be inclinded to decline your offer of a ride {:>) if you
have the lightest installation around.

    Ed Anderson
Matthews NC

I just lost an old racing friend in a Variez accident. We think it was
icing
and he got it on a road OK but the plane rolled over during the
run out and broke his neck killing him. This has seemed to happen
several times recently so it would be wise for everybody to check
their roll over structure and make sure it is high enough and plenty
strong.

Paul Lamar
 
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