[Philster]

A friend and I were discussing the weight limit of electric pattern planes. Section 1.2.3 of the Radio Control Aerobatics Rule Book 2007 states
"5 kg without fuel" and "Model aircraft using electric motors, as a power source, shall be weighed without batteries used for those motors".

Can someone confirm this?

Phil

[Guest]

Yes, for MAAC classes (Sportsman thru Expert) the rules were ammended to allow electrics to be weighed without batteries so as to not create a challenge to pilots who wanted to convert from glow to electric or give electric a try by forcing them to the 5kg limit, which would likely result in the need for more expensive equipment.

For FAI the 5kg rule with batteries still applies.

[Philster]

Ok. Thanks Chad.

Phil

[eajohnson]

Hey Phil I notice that the AMA rulebook seems to be different in this respect and stipulates that the aircraft be weighed with batteries:

(from http://www.modelaircraft.org/UserFil...Aerobatics.pdf)
4.3: Weight and Size. No model may weigh more than five (5) kilograms (11 pounds) gross, but excluding fuel, ready for takeoff. Electric models are weighed with batteries. No model may have a wingspan or total length longer than two (2) meters (78.74 inches).

I like the Canadian version a lot better -- much more approachable for noobs like us and gives access to many backup planes that we might have set up for use in electric IMAC which will tend to be over the pattern weight limit with batteries but OK without. Anyway, something to be aware of since many of the contests that are within range for us are in the USA. Chad, any comment?

[Guest]

The NSRCA has their own rules, unlike IMAC, pattern in Canada does maintain our own set of rules. I proposed to drop the weigh with battery stipulation primarily to allow people to use A123 type batteries in place of lipo's as a less expensive option to running electrics.

So far to my knowledge very few if any people have really deviated to alternative batteries etc. and made use of the rule changes....mainly because nobody weighs planes anyway. The rules are still somewhat self limiting, at the 2 meter size limit, even with weighing without batteries you are not going to be able to go much over 13-15 lbs RTF and still maintain a good power to weight ratio and wing loading for pattern. If the rule ever gets abused, the committee would revisit it and maybe modify it but at this time that is not the case.

An 11s or 12s A123 pack at 4000 ish mAh would be a good combination in the older big wing 2 meter model that could take advantage of this rule. A plane like that would still be competitive up to Masters and cost significantly less compared to a current setup.

If you are competing across the border obviously you need to ensure you are meeting the NSRCA rules, or have prior permission to fly an illegal model from the CD.

[Philster]

Bit of bummer about the AMA/U.S rules. I am seriously thinking of getting the 78" Extreme Flight Extra. To get 5Kg AUW the pack would probably be too small for 2 sequences.

However I'm guessing they will be willing to let us fly with a 13-14 lb plane. Seriously, if it gets too heavy it's only a handicap as Chad pointed out.

[hifly2104]

Originally Posted by Philster

Bit of bummer about the AMA/U.S rules. I am seriously thinking of getting the 78" Extreme Flight Extra. To get 5Kg AUW the pack would probably be too small for 2 sequences.

However I'm guessing they will be willing to let us fly with a 13-14 lb plane. Seriously, if it gets too heavy it's only a handicap as Chad pointed out.

I know nothing of the competition ,but the rule in itself is acontrdiction . Total weight without fuel is 5kg must be weighed with batteries well the batteries are the fuel in a sense

[Guest]

Phil, why do you need to fly two sequences? That is an IMAC thing, pattern only flies one at a time.

No one will likely give you any grief about that plane, its basically "fits" the rules. In reality, no one really worries if your plane is legal or not unless you are winning, then people will complain, which is fair enough. If you can earn a trophy you should do it on a level field without any "perceived" advantage or disadvantage.

Even at the US Nats your airplane does not get processed until you make the Finals (top in FAI, the rest can all fly illegal models and unless someone say's something nothing will be done about it.