The Federal Aviation Administration (FAA
) on Aug. 25 issued an Emergency Airworthiness Directive (AD) that orders inspection of the wing slats on newer Boeing
737 airliners within 24 days. The emergency AD aims to prevent a recurrence of the Aug. 20 non-fatal accident in which a China Airlines Boeing
737-800 caught fire after landing in Okinawa and was destroyed. The inspection order is mandatory for U.S. carriers, but foreign operators of the latest Boeing 737s normally comply voluntarily. China Air has already inspected its remaining Boeing 737-800s as has Japan’s Boeing 737-800 operators. Accident investigators say a bolt off the right leading edge wing slat pierced the fuel tank of the China Air 737-800 twinjet after it landed Aug. 20 at Naha airport. The directive covers 783 US-registered Boeing 737-600s, -700s, -700Cs, -800s, -900s and –990ERs operated by eight U.S. air carriers (AirTran, Alaska, Aloha, American, ATA, Continental, Delta and Southwest). The FAA
has received two reports of parts of the main slat track downstop assembly coming off the main slat track. In one case, presumably the China Air accident, the FAA said “following retraction of the slats after landing…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 AD requires repetitive inspections and a one-time torquing of the nut and bolt believed to have come loose in the China Air accident. A Boeing spokeswoman said the firm received four reports of the nut coming loose, prompting a service letter in late 2005 to operators of 2,350 next-generation 737s around the world.