China Airlines’ Fire Necessitates Checks of Boeing 737 Slat Mechanisms

Investigators have established that the post-landing fire that destroyed a China Airlines Boeing 737 in Okinawa, was probably caused by a bolt from the slat mechanism on the aircraft’s right wing puncturing a fuel tank (investigators discovered a hole in the fuel tank of between 2–3 cm in size) that allowed fuel to leak out.

As a result, the Federal Aviation Administration (FAA) has mandated prompt inspections (within 24 days) of the down-stop assembly of the slat mechanisms of all late model Boeing 737s (737-600, -700, -800, -900 and –900ER). In addition to inspections of the down-stop assembly—which limits the degree of the slats’ extension/retraction—the nut and bolt securing the assembly in place must be checked and tightened to specifications. The FAA has ordered that these inspections have to be repeated at least every 3,000 takeoff and landing cycles.

The inspections are very straightforward and airlines operating the more than 2,200 affected Boeing 737 models are not expecting any disruptions to services as a result.