ORIGINAL: RCKen

Your best bet is to simply stop crashing planes. I know that sounds a bit harsh, but that's the best way to get servos to survive a crash. It's very difficult to pick a servo to survive a crash. I have seen cheap $10 standard servos (plastic gears) survive a crash that totally rekitted a plane and on the other hand I've seen $100 high torque (metal gears) get toasted on deadstick in the tall grass. Every crash is different and puts different loads on a servo and it's gear train.

However, no matter what happens all servos involved in a crash should be suspect before putting back into another plane. Many things can happen in a crash from gear teeth ripping off, cracked gears, cracked cases, cracked circuit boards, and many other things that can bring down your next plane if you use those servos again. What I usually do with servos that have been in a crash is take them apart and inspect everything. The case, the gears, the circuit, and the wires. Then when I have the servo apart I will clean and re-lube the geartrain as I reassemble the servo. I have often found problems this way that very well might have brought down another a plane had I put them back into another plane without checking first. Without this inspection there is no way I would ever trust a crashed servo in another plane.

Ken