The shelter or NATO classification HAS (hardened aircraft shelter) is, according to official language, a building for protecting aircraft made of thick, reinforced concrete walls for single combat aircraft. Various generations of shelters have been designed since the formation of NATO. The one shown here originates from the 2nd generation and was increasingly built in the 1970s. Shelters are found on all air-combat mission airfields and are meant to protect aircraft located on the ground from direct hits. The complete building made of concrete and its steel doors are designed to withstand the force of a detonation. The semicircular construction corresponds to the state of the art for the most effective bearing strength for defensive buildings in the 70s. The method of erection differed from airfield to airfield, but was normally arranged in several loops. Every NATO airfield has to be able to service all types of aircraft, which is the reason why technical service components have mostly been standardised. The 7 most important items of equipment are shown here: the hall towing tractor serves to transport equipment inside the hall and outside on the apron. All the hydraulic functions on the aircraft can be checked using the hydraulic stand (H 2987 SUN Electric Systems). The starter unit (30 kVA) is indispensable for each jet engine beam, and these can be removed and refitted using the component crane. The 'Steinbock' lifting machine moves exterior tanks and weapons on the pylons.