FAA Proposes Further Inspections, Modifications of 727 and 737 Lap Joints

WASHINGTON - The Federal Aviation Administration (FAA) has
proposed that certain lap joints on 727 and 737 aircraft be
inspected and modified to prevent fatigue cracking. Cracking
could lead to a loss of fuselage integrity and possible rapid
decompression. Lap joints are points along the fuselage where
aluminum skin panels overlap and are riveted together.

The FAA issued two airworthiness directives to address this type
of fatigue cracking in 1997 and 1999. Based on subsequent
reports of cracking, the FAA has determined that the long-term
structural integrity of these aircraft would be best maintained by
modifying the lap joints rather than continuing to rely on the
existing inspections. Since no immediate safety-of-flight
problems have been identified, the proposed action will allow for
public comment until Aug. 27.

The proposed action comes via four notices of proposed
rulemaking (NPRMs) - one affecting 727s and three affecting
737s - that would require operators of U.S.-registered aircraft to
conduct revised inspections and make improved modifications to
certain lap joints.

The NPRMs cover approximately 700 727s and 900 737s
registered in the U.S. The cost for compliance would range from
$54,000 to $264,000 per aircraft depending on the modification.