[NSRCA-discussion] Weight

Thu Jun 4 11:22:09 AKDT 2009

Dave - you are 100% correct. I like Option C the best but Option A is is probably the best choice overall if you don't mind hearing the discussion about why it is the way it is. :) Option B could be dangerous and Option D could cause more problems / discussions than we have now. 

I believe it's in our best interest to just leave things the way they are now and move on. We all know the challenges of building a light electric vs. a glow airplane. It IS possible to be competitive with either one. If it weren't, EVERYONE would be flying either glow OR electric. Right now there's still a choice.

John Pavlick

--- On Thu, 6/4/09, Dave <DaveL322 at comcast.net> wrote:

From: Dave <DaveL322 at comcast.net>
Subject: RE:[NSRCA-discussion] Weight
To: jpavlick at idseng.com, "'General pattern discussion'" <nsrca-discussion at lists.nsrca.org>
Date: Thursday, June 4, 2009, 2:56 PM

“Simple solution to this seemingly impossible to solve problem: come up with a weight limit that is reasonable for a 2-meter Pattern plane that's READY TO FLY. That means an electric with batteries and a glow airplane with a full tank of fuel.”

Here’s the deal – not matter how we got here, we do have a max takeoff weight now for electrics which is 11 lbs, and electrics are competitive with glow which clearly have an advantage as they do not have a maximum takeoff weight.  What are the options to “level the playing field”, and what results will the “changes” bring:

Option A – leave the rules and current interpretations alone.  Result – minor improvements in glow before it’s imminent death, and considerably more improvements in electrics (in terms of performance and reduced cost).  The latest and greatest costs money/time/resources, and “I want new stuff now for what the old stuff costs” just isn’t reality.

Option B – to level the playing field, increase the takeoff weight limit to whatever (11.5, 12, 12.5 lbs) for both glow and electric, and you have ZERO performance increase with glow, and you have a HUGE opportunity to increase the performance of electric (which WILL happen).  Result – the imminent obsolescence of glow will occur faster, and performance and COST will increase for electric which will be the only viable option for those that want to compete without being at a disadvantage.  I think a bad scenario for everyone (excepting maybe the battery manufacturers).  AND, in truth, I can envision some minimal increases in glow depending on the exact setup and weight limit, but it will be at increased cost, and it the increased performance will be a fraction of the extra performance the electrics will gain.

Option C – to level the playing field and prevent an escalation in costs (of glow or electric), enforce an 11 lb takeoff weight for glow and electric.  Result – even faster obsolescence of glow, and no escalation in costs of electrics (which will continue to improve in performance while decreasing in costs).  The average glow plane / engine would need some serious work, but there are plenty of options for those that care to look.  Numerous composite or “roach” ships can be built at <10 lbs, without spending $3500 for a custom Oxai (nothing wrong with that of course), and plenty of power options exist to get through a sequence on less than 16 oz (by weight) of fuel.  My last glow plane (hanging on the ceiling untouched since June 2006) was a Vivat / Webra 160, and it was 10.5 lbs at takeoff, and that combo is still competitive today through Masters or P09.

Option D – attempt to establish differing takeoff weights for every viable power system, and perpetually adjust the takeoff weight limits as technology changes.  Result – moving targets for manufacturers (bad), none of the weights will ever be reduced (because that would obsolete some equipment in use), the escalation of weights will slowly and inevitably creep up for all powerplants, and the costs will go up for everyone….and the administrative/technical/logistical/tech inspections for planes will be far more complex.  By far the worst option.

Glow already has an advantage, and it is going to die anyway.  Excepting Option D (by far the worst option), electric will be dominant, and the best electrics with the best performance will always cost more (performance always has a cost in open competition).  To me, the only decision is how much do you want the electrics to cost when glow is obsolete?  I’d prefer to keep rules as they are and, not allow the costs to go up (yet another time) for either glow or electric.

Regards,

Dave

From: nsrca-discussion-bounces at lists.nsrca.org [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of John Pavlick
Sent: Thursday, June 04, 2009 1:52 PM
To: General pattern discussion
Subject: Re: [NSRCA-discussion] Weight

What everyone is dancing around is the fact that there are 2 definitions of "takeoff weight". One for glow / gas powered airplanes and one for electrics. Being an engineer and a somewhat logically minded person I would say that the correct definition of "takeoff weight" would include batteries, fuel, protoplasm -  whatever is necessary to allow the airplane to fly. I'm sure most people would agree. 

The "problem" comes form the fact that some people believe there is no way of verifying the amount of fuel that would be put into a glow / gas airplane when it's weighed (people might put half a tank of fuel in and then get the airplane weighed), so they decided to weigh them without fuel. Solved the problem - but created another one when electrics became popular. Let's see. How hard is it to make sure you have a full tank of fuel? Doesn't it run out of the overflow? Is it really that hard? I know it might take longer to verify that the tank is full but if that's what needs to be done then so be it. How do you know that the batteries are installed in an electric? How can you be sure that every time that plane is flown in the contest, the batteries will weigh the same (someone could weigh in with smaller batteries)?

I REALLY wish more of you guys were involved in car racing. 99% of these ridiculous "problems" would be avoided. Here's how it works: Before the car goes on the track it's inspected. If it meets the rules (weight, size, safety equipment, etc.) it gets stickered. NOW it can race. Cars are usually checked before they go out and when they come off the track. If you place in the top 3 the engine usually gets torn apart. Cheaters get caught by the tech. inspectors. Everyone knows the rules and all the cars running in a given class must meet those rules. It's not rocket science. If a bunch of good ole' boys at a dirt track can do it - why can't we? LOL

Simple solution to this seemingly impossible to solve problem: come up with a weight limit that is reasonable for a 2-meter Pattern plane that's READY TO FLY. That means an electric with batteries and a glow airplane with a full tank of fuel. Of course you can fly with less fuel or smaller batteries if you want to be lighter but what we're looking for is a worst case / maximum weight scenario. To be fair, the planes should be weighed before thay take off and after they land. Do you need to do this at local contests? No, I don't think so. How many planes are weighed at local contests now? Should you do this at the Nationals? Absolutely. Anythng else will only lead to more discussion, explanation and discontent. 

John Pavlick

--- On Thu, 6/4/09, J N Hiller <jnhiller at earthlink.net> wrote:

From: J N Hiller <jnhiller at earthlink.net>
Subject: Re: [NSRCA-discussion] Weight
To: " General pattern discussion " <nsrca-discussion at lists.nsrca.org>
Date: Thursday, June 4, 2009, 1:08 PM

Using the FAI weight limit allow one to fly the same airplane in both FAI
and AMA pattern.
Jim Hiller

-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Bill's Email
Sent: Thursday, June 04, 2009 9:42 AM
To: General pattern discussion
Subject: Re: [NSRCA-discussion] Weight

What everyone is dancing around here is the fact that the 5 kg (+/- 11
pound) weight limit is a completely arbitrary number that has no
foundation in anything other than FAI used to have this limit for all RC
models. In FAI being at or below 5 kg was what defined you as a radio
controlled "model" airplane.

Here is the weight rule for F3B gliders:

5.3.1.3. Characteristics of Radio Controlled Gliders F3B
a) Maximum flying mass ........................................ 5 kg

F3J Gliders:

5.6.1.3. Characteristics of Radio Controlled Gliders
a) Maximum Flying Mass .................................. 5 kg

F3F Slope RAcing Gliders:

5.F.2. Characteristics of Radio Controlled Slope Gliders
Maximum flying mass ........................................ 5 kg

F3C helis are now 6 KG so even the FAI can change their minds.

Point being is that the 5 kg "limit" has no real life basis beyond what
was in the FAI sporting code at the time the AMA rules were written. FAI
was not looking at all the convoluted logic about cost, etc. At the time
that was simply how they defined (and still do for many RC events) what
a model airplane is.

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