41 C.F.R. § 102-33.140

You must account for the operations and ownership costs of your Government aircraft, including UAS, as outlined in the U.S. Government Aircraft CAG at gsa.gov/aviationpolicy, in accordance with OMB Circular A-126. At a minimum, you must:

(a) Justify acquisitions to support the agency's aviation program;

(b) Justify the use of Government aircraft in lieu of commercially available aircraft, and the use of one Government aircraft in lieu of another;

(c) Develop a variable cost rate for each aircraft or aircraft type in your inventory;

(d) Recover the costs of operating Government aircraft;

(e) Determine the cost effectiveness of various aspects of agency aircraft programs; and

(f) Accumulate aircraft program costs following the procedures defined in the CAG.