The primary duty of the waist gunner was to defend the aircraft against the enemy. On a B17, there were two waist gunners located directly opposite one another. This made maneuvering sometimes difficult, and until later models of the B17, frostbite was also an issue, as the waist gunners stood near open window areas. Because of this, waist gunners frequently wore heavy layers of shearling and leather protective clothing, as well as electrically heated suits. Waist gunners were also frequently responsible for checking the aircraft for damage and assisting the flight engineer with repairs if necessary.