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-----Original Message-----
From: William R. Bayne [mailto:[EMAIL PROTECTED]
Sent: Friday, December 30, 2005 12:25 AM
To: Ed Burkhead
Subject: WRB Re: [COUPERS-FLYIN] Weight & Balance
RLYFLYIN
Hi Jose,
The D Model came out of the factory about 815 lbs. (unpainted, fabric
wings).
The E Model was about 815 (unpainted, fabric wings). Service Ceiling:
11,000'
A G Model was around 833 (fabric wings).
To all of the above, add 32-40 lbs. (useless non-structural weight) for
metal wings.
Forney F-1 Models are around 915+, depending on instrumentation (metal
wings
standard).
F-1A Models, Alons and M10s are all heavier, with 1450lb. gross (metal
wings
standard).
Subtract above empty weights for "typical" payloads for each model (when
new).
As Percy has said previously-airplanes, like pilots, tend to get heavier
as
they age.
It is easier to remove useless weight from an airframe than from the
pilot
(and passenger;<).
Fuel weight varies with fuel capacity. Fuselage tanks can be (roughly)
five
or six gallon.
Wing tanks can be (roughly) eight or nine. Until measured, one can only
guess.
The M10 Cadet Owners Manual claims a 24 gallon capacity, of which 23.5 is
shown useable.
Alon Service Bulletin A-10 (M10-1) requires the aircraft weight and
balance
record be corrected by adding 15.5 lbs. unusable fuel to empty weight of
aircraft. If we presume fuel to weigh 6 lbs./gal. (as Erco did), the
amount
of unusable fuel has been increased to 2.58 gallons!
So, you can see that the devil is in the details; even in the last
production airframes.
You stated a full fuel weight to two decimal places, but didn't indicate
how
you reached that precise figure. Erco used 6 lbs./gallon in their
calculations. Gas really averages a bit more, but no one will complain
if
we use the same for our calculations. It would suggest you have 23.28
gals.
usable fuel. That's certainly in the ball park for a coupe with the six
gallon nose tank and nine gallon wing tanks. Did you measure it? (five
stars if you did, six if you used the method I recently described on
Tech)
For flight planning purposes "Payload" for a given coupe is the
allowable
gross weight less the sum of the airframe's REAL empty weight and the
weight
of engine oil and unusable fuel. Few coupes have been recently weighed,
and
almost all really weigh even more than their paperwork admits. Few
unrestored ones are much under 900 lbs.
Knowing YOUR true payload, YOUR usable fuel, YOUR "normal" (leaned?) fuel
burn and YOUR ground progress allow you to plan and adjust (as
necessary) cross country capability for maximum utility and (at least to
me)
fun with safety, confidence, and pride in a task done well.
There's a wonderful article on this approach to flying in the January
'06 AOPA Pilot, p. 85.
Regards,
William R. Bayne
<____|-(o)-|____>
(Copyright 2004)
--
On Dec 29, 2005, at 8:19 PM, <[EMAIL PROTECTED]> wrote:
Starting to look at some W&B on Ercoupes and have a few questions ...
The coupes with Gross Weight of 1400 lbs and metal wings ...
What is the typcial empty weight, useful load and payload?
I am figuring with full a fuel weight of 139.68
Thanks in advance.
Jose Gibert
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