[...] The key to eliminating this problem is to extend the ice vanes at +5º C when in visible moisture. If its night and you can’t tell if visible moisture is present, extend them anyway!
Of course, FOD isn’t only ice induced.
The following actions should be taken by pilots to reduce the potential of F.O.D. during ground operations:
1, Following maintenance, ensure that the mechanic hasn’t left anything in the intake. Even a small safety wire clipping can F.O.D. an engine.
2. Avoid run-ups in areas containing loose gravel or sand.
3. Avoid use of reverse at low ground speeds.
4. Do not use reverse to position the aircraft on the ground.
5. In newer King Airs, consider extending the ice vanes just prior to landing, especially if you are planning on using heavy reverse. KingAirTraining.com