41 C.F.R. § 102-33.80

When hiring CAS, you must:

(a) Establish agency-specific Flight Program Standards as applicable and require compliance with these standards in your contracts and agreements;

(b) Account for the cost of your aircraft and services hired as CAS;

(c) Account for the use of your aircraft hired as CAS; and

(d) Report the cost and usage data for your CAS hires.