The KC-135 Stratotanker is a key asset in US military operations, primarily used for aerial refuelling to extend the range and endurance of fighter jets, bombers and other aircraft. A Boeing KC-135 Stratotanker has gone missing over Qatar after issuing a 7700 emergency distress signal during a mission in the region. The aircraft had taken off from Al Dhafra Air Base in the United Arab Emirates and was supporting ongoing military... [1908 chars]