Kitsune, Lockheed can not issue an AD only a National Airworthiness Authority (NAA) can issue such. What Lockheed may do is issue a service bulletin(SB) and the FAA (as state of design) may then further mandate the SB to make it an AD, TBH being involved with the MAOS and Mil 145 implementation and the Haddon Cave report it would be difficult for the RAF/MoD to sidestep any such directive if issued.