Johnny Whitaker, academy spokesman, said the probe showed that some cadets had previously cheated, and that enhanced their punishment. Cadets given probation will have to write papers and meet regularly with a mentor. Air Force Academy, Colo. – The Air Force Academy said Tuesday that it will expel 18 cadets who cheated on a military-knowledge test and place 13 other cadets on probation, ending a cheating investigation that began in February. Of 40 suspects, 31 were found in violation of the honor code that says: “We will not lie, steal or cheat, nor tolerate among us anyone who does.” Twenty-nine of the 40 cadets, all freshmen, admitted cheating. Of five cadets who denied cheating, two were found guilty. The cheating occurred when cadets found quiz answers on a social networking Web site.