AD FAA-2013-0546

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 727 airplanes. This AD was prompted by certain mandated programs intended to support the airplane reaching its limit of validity (LOV) of the engineering data that support the established structural maintenance program. This AD requires, for certain airplanes, a modification of the web of the horizontal stabilizer center section rear spar. For the other airplanes, this AD requires an inspection for cracks in the web, and repair or modification as applicable. We are issuing this AD to prevent cracking at the upper fastener holes in the riveted web in the horizontal stabilizer center section rear spar, which could result in failure of the spar forging and lead to horizontal stabilizer separation and loss of control of the airplane.