Update: Boeing has reportedly clarified the 777-200ER Malaysia Airlines aircraft did not have such an antenna installed and was not subject to the FAA order. In a brief statement sent to the Guardian, Boeing said: “The antenna covered by the pending AD was not installed on MH370, so that airplane is not subject to the AD or the related Service Bulletin.”

The US Government Printing Office published a Federal Aviation Administration airworthiness directive in September 2013 “to detect and correct cracking and corrosion in the fuselage skin, which could lead to rapid decompression and loss of structural integrity of the airplane”.

The directive was applicable to “The Boeing Company Model 777-200, -200LR, – 300, -300ER, and -777F series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 777-53A0068, dated June 12, 2013″.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 777 airplanes. This proposed AD was prompted by a report of cracking in the fuselage skin underneath the satellite communication (SATCOM) antenna adapter. This proposed AD would require repetitive inspections of the visible fuselage skin and doubler if installed, for cracking, corrosion, and any indication of contact of a certain fastener to a bonding jumper, and repair if necessary. We are proposing this AD to detect and correct cracking and corrosion in the fuselage skin, which could lead to rapid decompression and loss of structural integrity of the airplane. Full proposed directive

The US Federal Register later announced that the rule was being adopted:

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400, -400D, -400F, and 747SR series airplanes. This AD was prompted by reports of cracking at the aft upper corner of the main entry door (MED) 5 cutout. This AD requires inspecting for the presence of repairs and measuring the edge margin at certain fastener locations around the upper aft corner of the door cutout, inspecting for any cracking of the fuselage skin assembly and bear strap in the aft upper corner area of the door cutout, and repairing or modifying the fuselage skin assembly and bear strap if necessary. We are issuing this AD to detect and correct cracking of the skin and bear straps at the aft upper corner of the MED 5 cutout, which could result in in-flight depressurization.