Heat
From the sounds of it, you were not going to use a circuit board were you? just free wire the thing?
If that is so, then the PIC may or may not give you 60ma as the board acts as somewhat of a heatsink.
But you also said it's going on an RC plane I do believe so if you mounted it correctly you could use the rushing air for an effective cooling system.
It all comes down to how effectively you cool the thing. You may be able to tack some small tin-foil heat sink fins on it but I guess there are a million different ways to do it and transistors were mentioned as they are a proven and reliable design.
So taking all that in to consideration, I wish you luck and make sure ya come back here and let us know what ya did and if it worked, but also remember, what works in the short term, may burn out in the long term.
R.