FAA issues emergency airworthiness directive for Boeing 737

The Federal Aviation Administration (FAA) has issued an emergency airworthiness directive (AD) for Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series aircraft. The AD arose from the discovery of loose or missing parts from the main slat track downstop assemblies on these aircraft, "which could result in a fuel leak and consequent fire" if not detected and corrected.

Emergency AD No. AD 2007-18-51 was issued on August 25, 2007, and is effective immediately upon receipt.

The FAA provides this background information:

We have received reports of parts of the main slat track downstop assembly coming off the main slat track.

In one case, a nut fell into the slat track housing (referred to as “slat can”) and, during a subsequent slat retraction, the track made contact with the nut, pushing it into the wall of the can and puncturing it. That operator reported finding fuel leaking from the drain hole in the slat track housing at the No. 5 slat track position.

In another case, an initial investigation revealed that following retraction of the slats after landing on a Model 737-800 airplane, loose parts of the main slat track downstop assembly punctured the slat can, which resulted in a fuel leak and a fire that ultimately destroyed the airplane.

The emergency AD requires:

...repetitive detailed inspections of the slat track downstop assembly to verify that proper hardware is installed, one-time torquing of the nut and bolt, and corrective actions if necessary.

Corrective actions include installing a new or serviceable part; and doing a detailed inspection of the inside of the slat can for foreign object debris (FOD) and damage, and removing any FOD and repairing damage that is found.

Here is the link to the full text of FAA AD 2007-18-51 (5 page 'pdf' file).

UPDATE August 29, 2007: In a relatively unusual move, the FAA has issued another Emergency AD about the same problem, just 3 days after it issued the first. Apparently the FAA has received still more reports of parts coming off the main slat track downstop assemblies and ending up in the slatcan. So, the new EAD reduces the time for compliance from 24 days to 10 days.

Here's the link: FAA Emergency Airworthiness Directive No. 2007-18-52 - 6 page 'pdf' file