AD NUMBER: 2012-23-08

PRODUCT: Certain Boeing 737-600, -700, -700C, -800, and -900 series airplanes.
SUBJECT: Airworthiness Directive 2012-23-08
ACTION: Final Rule

SUMMARY: The FAA is superseding an existing airworthiness directive (AD) for the products listed above. That AD currently requires replacing the drain tube assemblies and support clamps on the aft fairing of the engine struts.

This new AD requires replacing the drain tube assembly of the left and right engine strut aft fairings with a new one, which includes an integral support clamp made of nickel alloy 625. This AD also adds airplanes to the applicability. This AD was prompted by a report of a broken drain tube assembly on the left engine strut at the clamp support location under the aft fairing compartment, inside the heat shield cavity of the aft fairing. There have also been reports of tube wear at this clamp location on additional airplanes.

The FAA is issuing this AD to prevent failure of the drain tube assemblies and clamps on the aft fairings of the engine struts. Such failure could allow leaked flammable fluids in the drain systems to discharge onto the heat shields of the aft fairings of the engine struts, which could result in an undetected and uncontrollable fire.

DATES: This AD is effective December 31, 2012.

FMI: AD