| >> is 1 hp to 6 pounds. Many of the 3D capable aerobats have 1:1 or better | >> hp to weight ratios.

Translation with units: 1 hp : 1 lb.

... which seems way overpowered to me though, even by R/C standards. And really, you don't need massive amounts of power to do 3D -- just lots of static thrust. Though of course the two are related.

Pylon racing, that's a good place for lots of power. A 3D plane needs a decent amount of power, but one horse power per pound still seems awfully high.

Picking a typical engine known for being relatively powerful (though finicky), the Tower Hobbies 0.46 engine is rated at 1.75 HP maximum and weighs 1.05 lbs. That gives a hp:lbs ratio of 1.66, but merely adding 11 oz of fuel brings the hp:lbs ratio to 1.00 -- and we don't even have an airplane involved yet. (But I am including the muffler.)

I've checked a few other engines, and haven't found any higher hp:lbs ratios yet ...

(And I won't even get into how tricky it can be to get an R/C IC engine to put out the rated power in the real world.)

As an extreme example of a 3D aerobat, my Tensor 4D weighs around 0.6 lbs, and I think the maximum power draw is around 100 watts, or 0.13 hp. That gives a hp:lbs ratio of 0.2. Though as I said, this is an extreme example. Also note that I'm measuring power into the motor, and the mechanical power emitted by the motor is probably around

20-30% less, which would make the hp:lbs ratio even lower.

... | > power to weight needs to be 1.2 to 1 to get a plane to accelerate from a | > hover IIRC

Obviously he's meant static thrust rather than power there. And in that case, the exact ratio varies based on who you ask, and it's not an exact ratio anyways, but he's basically right. | Thats two crap answers in succression. | | power is not thrust.

I was thinking the same thing, but decided not to say anything since the context tended to explain what they were referring to. | Power to weight cannot be expressesd as a simple ratio, since the units are | not identical.

Right, but people are loose with units around here anyways.

| Mind you, considiring the posters, its likley that they think it is.

I suspect not. But that was a nice dig anyways.