TAKEOFF TUBE

Alaska Airlines Flight 261, a McDonnell Douglas MD-83 aircraft, crashed on January 31, 2000 in the Pacific Ocean about 2.7 miles (4.3 km) north of Anacapa Island, California. The two pilots, three cabin crewmembers, and 83 passengers on board were killed, and the airplane was destroyed. Alaska 261 was a scheduled international passenger flight from Lic. Gustavo Díaz Ordaz International Airport (PVR), Puerto Vallarta, Mexico, to Seattle-Tacoma International Airport (SEA), with an intermediate stop planned at San Francisco International Airport (SFO).[1] The subsequent investigation by the National Transportation Safety Board determined that inadequate maintenance led to excessive wear and catastrophic failure of a critical flight control system during flight. The probable cause was stated to be "a loss of airplane pitch control resulting from the in-flight failure of the horizontal stabilizer trim system jackscrew assembly’s acme nut threads. The thread failure was caused by excessive wear resulting from Alaska Airlines’ insufficient lubrication of the jackscrew assembly.