All test flights and ferry flights require prior DCA approval, as well as approval from all States over-flown. The application for a Special Flight Permit can be made by using form INS-4.034.
Special Flight Permit can be granted to the operator of an aircraft only for the purpose of flying the aircraft to a place where maintenance, permanent repair or alterations are to be performed; or for the purpose of conducting a flight associated with the approval of a modification.
AUA-RLW details the requirements for the issue and renewal of a Special Flight Permit.