[NSRCA-discussion] Fwd: Electric Weight Proposal Logic andRationale

[Jim Woodward]

I think someone should find Dave Lockhart's previous posts on this
matter and forward them to John.

Jim W.

 

 

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From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Robert &
Casey Green
Sent: Thursday, June 21, 2007 1:51 PM
To: NSRCA Mailing List
Subject: Re: [NSRCA-discussion] Fwd: Electric Weight Proposal Logic
andRationale

 

I agree with John on this.  my .02 cents

	----- Original Message ----- 

	From: Ron Van Putte <mailto:vanputte at cox.net>  

	To: NSRCA Mailing List <mailto:nsrca-discussion at lists.nsrca.org>


	Sent: Thursday, June 21, 2007 10:08 AM

	Subject: [NSRCA-discussion] Fwd: Electric Weight Proposal Logic
and Rationale

	 

	I got the following from John Fuqua.  He is going to submit a
proposal to increase the weight limit for electric-powered airplanes to
11.5 lbs.  I suggested to him that he "float" his rationale by the NSRCA
Discussion List, to get some feedback.  Here is his response. 

	 

	Ron Van Putte

	 

	Begin forwarded message:

	
	
	

	Date: June 21, 2007 10:40:36 AM CDT

	To: "Ron Van Putte" <vanputte at cox.net>

	Subject: Electric Weight Proposal Logic and Rationale

	 

	Now that I am flying electrics I have come to realize the
penalty that electric planes have when being built that gas planes to
not have.  That building penalty is significant under the current rules.
Electrics must be built lighter, to include paranoid attention to
everything used - wood, paint, fittings, etc., - all to make weight.
Much more of a concern than gas planes.  Also I remember many instances
at the NATs when we were weighing airplanes, when the contestant was
doing all he could do to meet weight with a gas plane to include
cleaning the fuel residue inside and out.   A lot of gas planes were
weighing in at 10lb 11oz, 10lb 11.9 oz, even one that was only a few
grams under 5 kilos.   Then they get to add a minimum of 16 to 20 ozs of
weight by fueling up (and there is no limit to fuel capacity).  Takeoff
weights are 12 lbs or more.   This situation seems bizarre and illogical
when you put some thought into it.  Electrics have a finite weight and
gas planes are open ended at Takeoff.   Even though the 2005 NSRCA
survey did not support an electric weight increase it occurred to me
that the survey did not offer any logic or rationale as to why some
increase would be justified or not.  I have attempted below to come up
with a reasonable compromise on electric weight allowance.  I believe
the rationale supports an increase but it would be nice to have NSRCA
membership look at it to find the fatal flaw in the rationale before it
gets submitted.  The two paras below are taken from the proposed change.
Lets put it out and see what the discussion list comes up with.

	John 

	Change paragraph 4.3 Weight and Size page RCA-2 to read:  No
model may weigh more than 5 kilograms (11 pounds) gross, but excluding
fuel, ready for takeoff.  Electric models are weighed with batteries and
are allowed an additional 8 ounces for a total of 11.5 pounds ready for
takeoff.   No model may have a wingspan or total length longer than two
(2) meters (78.74 inches).

	 

	Logic behind proposed change, including alleged shortcomings of
the present rules.  State intent for future reference. 

	Today's 2 meter RC Aerobatics fuel powered aircraft typically
use fuel tanks with a 20 fluid ounce capacity.  A 20 fluid ounce Crank
Tank containing 25% Cool Power Pro Pattern fuel was tested.  The fuel
weighed 17.3 ounces.  Allowing for variation in tank sizes and fuel type
a conservative weight of 16 ounces of fuel on average seems appropriate.
This means that an allowable takeoff weight for fuel powered aircraft is
at least 12 pounds.   Assuming that all fuel is consumed during the
flight, the average weight for the aircraft is 11.5 pounds.  By
restricting electric powered aircraft to the takeoff weight of unfueled
aircraft an unfair weight penalty is being arbitrarily imposed against
the electric model.  By allowing electric aircraft an AVERAGE flying
weight of the fuel powered aircraft, flying weight equity is restored.

	 

	
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