A fun aspect of the sport of RC modeling is called aerotowing. Just like you tow a broken down car on the side of the road with a strap; with models, a powered model tows an unpowered one (a glider). Once at altitude, release the line and fly!
When servos are damaged in a crash, you pray it's just a set of gears instead of a gearset 'and' the case because if it's both, then it instantly becomes a throwaway!