AD FAA-2013-0673

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 707 airplanes; and Model 720 and 720B series airplanes. This AD was prompted by reports indicating that a standard access door was located where an impact-resistant access door was required, and stencils were missing from some impact-resistant access doors. This AD requires an inspection of the left- and right-hand wing fuel tank access doors to determine that impact-resistant access doors are installed in the correct locations, and to replace any door with an impact-resistant access door if necessary. This AD also requires an inspection for stencils and index markers on impact-resistant access doors, and application of new stencils or index markers if necessary. This AD also requires revising the maintenance program to incorporate changes to the airworthiness limitations section. We are issuing this AD to prevent foreign object penetration of the fuel tank, which could cause a fuel leak near an ignition source (e.g., hot brakes or engine exhaust nozzle), consequently leading to a fuel-fed fire.