In the missile called a "SAM", it's what the "A" stands for
The Buk is a mobile, radar-guided surface-to-air missile (SAM) 
missile... [DOC] [TLE] MIM-104 Patriot - Wikipedia [PAR] The MIM-104 Patriot is a surface-to-air missile (SAM) system, the primary of its 
kind used by the ....