Yes, you may not acquire -
(a) More aircraft than you need to carry out your official business;
(b) Aircraft of greater size or capacity than you need to perform your Governmental functions cost-effectively; or
(c) Federal aircraft that Congress has not authorized your agency to acquire or Federal aircraft or commercial aircraft and services for which you have not followed the requirements in OMB Circulars A-76 and A-11 (available at http://www.whitehouse.gov/omb).