Summary: GAO reviewed more than 200 trips that 11 executive branch officials took on military aircraft between January 1989 and March 1991 that sometimes mixed official, political, and personal business. This report (1) discusses the extent of travel by the officials on military aircraft, (2) identifies the policies governing that travel, (3) discusses compliance with travel policies, and (4) identifies the operating costs of military aircraft used for political and personal travel. GAO found that 10 of the officials generally followed the travel regulation. The former White House Chief of Staff, however, often traveled without obtaining required authorization; in addition, the travel classification was ultimately changed for 21 of his trips, resulting in a reimbursement to the government of more than $5,000. The White House has since taken several steps to strengthen controls over travel. The Secretary of State, on the other hand, was not initially billed for three trips that mixed official and personal business. As a result of GAO's review, the government was reimbursed about $2,300, and the Secretary of State now flies commercial aircraft for personal domestic travel. For the 35 solely political and personal trips on military aircraft for which the official was the primary traveler, the estimated cost exceeded $750,000; reimbursements for this travel totaled about $61,500.