[NSRCA-discussion] Airplane Weight Limits

[Mike Hester]

LOL

Seriously that's real. I know that some people say they don't have any 
problems with speed/wind, but my eyes tell me different. I recently watched 
an avid electric competitor smoke 2 sets of packs, back to back, and as a 
result will not compete in the 2007 Nats without a YS powered plane. For 
this person to make this kind of move, it's like one of the signs of the 
apocalypse. I watched the masters Nats finals last year (from the judges 
chair) and the lack of penetration was extremely evident in the head wind. I 
was not on the FAI line so I can't say one way or another how things went 
there. But my eyes work, and I know what I have seen, there and other places 
as well. When you have to bury the stick just  to maintain any forward 
motion whatsoever, you will be hard pressed by the end of the flight. Simple 
physics.

The problem exists, however I'll be the very first to admit it comes down to 
mostly set up, equipment, and throttle management all combined. Therefore my 
main concern is not how you guys handle it, it's how everybody else does.

I have spent countless hours on the phone with Dave Lockhart discussing 
these things, and I can't tell you how much I've learned in the last couple 
of years. Keep in mind I have nothing to gain or lose either way, I don't 
fly electrics. But I do have to build them for others and one thing I hate 
is when anyone has problems with a plane I built, regardless of the source 
of the problem. So, I sort of take it upon myself to try and figure out 
solutions.

My conclusion is this: just like with any glow plane, there is no substitute 
for power. if you're marginal on your set up because of weight restrictions, 
available equipment, or most likely $$$, you will pay for it when 
competition circumstances deteriorate. Especially with older equipment.

In my opinion, the answer does not lie in a rule change. It lies squarely on 
the shoulders of the equipment manufacturers and the guys having real 
success to share thier findings in a truthful manner. We all know electric 
power is still very much in it's infancy and the progress made in the last 
couple of years is nothing short of outstanding. We're just not quite 
"there" yet for Joe Average. But we're a LOT closer than we were 2-3 years 
ago, and closer than we were last year at this time. I'm really excited 
about it all, and I appreciate the guys who I build planes for because I can 
do all of this research without having to spend my own money =) LOL

One thing you touched on that is real to me is the need for higher pitch 
props in various sizes. I honestly believe the solutions to these particular 
problems lie down that path. More pitch=more speed=no problems. I've seen 
set ups that handled these conditions fine (Like the plane I built for Emory 
Schroeter, and his packs are NOT new by any means) but at the same time I 
watch a more standard set up fry right next to it on the very next flight. 
John for instance was ok, but marginal. Luckily those packs were brand new, 
but you can't tell me they didn't suffer damage. He put back more capacity 
than the battery was even rated for. When he took them out of the plane it 
was uncomfortably hot to the touch. the packs measured about 130 degrees F.

maybe the real problem is that by the time he finally gets a set up that 
allows him to push the limits, the plane is pushing the weight limit. The 
set up for this kind of power is really heavy. For reference, that airframe 
itself was less than 4 1/2 lbs finished on the gear. So I think perhaps what 
has John's hackles up is that most other planes simply wouldn't make weight 
with a set up like that one. hence the need for a really expensive airframe 
(I'm not cheap, but anyone with any building skill could do it too...but 
then what's your time worth? Personal choice there and a whole 'nuther can 
of worms).

Didn't mean to type a novel or even crack this one open in any more detail, 
but I wanted to underscore my personal opinions that the burden lies with 
the manufacturers and test pilots. And they are doing a great job, it just 
takes time.

-Mike

----- Original Message ----- 
From: "Chad Northeast" <chad at f3acanada.org>
To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
Sent: Friday, June 22, 2007 9:06 AM
Subject: Re: [NSRCA-discussion] Airplane Weight Limits


> Interestingly enough, up here we changed MAAC rules (similar to how you
> are setup with AMA/FAI separated), so that planes are weighed without
> batteries.  Did it about two years ago so as to allow guys to use other
> technology than Lipos (A123's for instance).  To date nobody has ever
> bothered to do anything different, and I am sure most planes have been
> close to the conventional weight limit, regardless of class.
>
> As for FAI, come 2008 weight limit wont matter much.  With the shorter
> sequences you could run a smaller pack fairly comfortably.  As well
> there is a 50 gram allowance I believe, so you could be 5050 grams and
> still be ok.  Just shortening the schedules will give electric a pretty
> nice boost, it will finally allow us to haul ass in a 7 min schedule and
> demonstrate the much needed wind killing speed that many say we dont
> have :-)  Time to get APC to make that 20x16 :)
>
> Chad
>