If you haven't been in, or associated with the military, you probably have never heard of FOD. But anywhere there are jet planes, and specifically, in dusty deployed locations, FOD (foreign objects and debris) is a big deal. The little pebbles and gravel which account for the great majority of the open spaces, roads and walkways around here are serious hazards for jet engines that can suck in the FOD when revving up for take off. The F-16s, of which there is a squad here, are particularly susceptible given the large thrust - ergo vacuum with respect to FOD - and short distance to the ground where the FOD lies. This is such a costly problem that there are people who write newsletters on FOD... ...really: http://www.fodnews.com/article0r.html
Approaching the flight line, and everytime after re-entry into the flight line, the wheels of the vehicle driving on the line need to be checked for pebbles and dirt between the treads. There are even special FOD tools, which look like dull box knives, made specifically for digging the FOD out of the tires. On really muddy days there are pressure washers to remove large amounts of mud and stones.
This seems like such a low tech problem for such a high tech piece of machinery, and it reminds me that our fancy technology's survival is fragile. Volcano dust or dirt runways can ground American's air fleet. Maybe there is wisdom to hanging on to some low-tech options to survive the natural disasters, EMPs or defense computer hackers.