Mexicana Flight 940
A Mexicana 727 similar to the one involved
|Date||31 March 1986|
|Summary||Maintenance error, loss of hydraulic and electrical systems, and in-flight fire|
|Aircraft type||Boeing 727–264|
|Operator||Mexicana de Aviacion|
|Flight origin||Benito Juárez International Airport|
|Stopover||Lic. Gustavo Díaz Ordaz International Airport|
|Destination||Los Angeles International Airport|
Flight 940 was operating its scheduled flight route Mexico City-Puerto Vallarta-Mazatlán-Los Angeles operated by Mexicana Airlines (Compañia Mexicana de Aviación). On March 31, 1986, the flight departed from Mexico City utilizing a Boeing 727-264 registered as XA-MEM. Fifteen minutes into the morning flight, the plane crashed into a mountain named El Carbón in the rugged Sierra Madre Oriental mountain range of central Mexico.
The plane, nicknamed "Veracruz", was piloted by Captain Carlos Guadarrama Sixtos, an experienced Mexicana captain with 15,000 hours of flying experience. The crew of eight included five flight attendants; the wife of the captain, an off-duty flight attendant, and his two sons were on board. 159 passengers were on board. At 8:50 in the morning, the plane took off from Benito Juárez International Airport en route to Los Angeles International Airport with stopovers in Puerto Vallarta and Mazatlán.
At 9:05 in the morning, an explosion shattered the fuselage. Captain Guadarrama and the crew in the cockpit, realizing that the plane was shaking too much, declared an emergency to the air traffic controller and asked to return to Benito Juárez International Airport for an emergency landing. The airport was prepared for the landing, but before reaching its destination the plane broke in two, burst into flames and crashed on El Carbón mountain near the town of Maravatío, Michoacán. Eyewitnesses reported details of the crash to authorities. All 167 passengers and crew were killed instantly. After the crash, some townspeople stole items that belonged to the victims. The local police and the Mexican army were called and the crash site was closed to unauthorized people so that investigations could begin.
Investigation and aftermath 
Initially, two Middle Eastern terrorist groups claimed responsibility for the crash. An anonymous letter signed by those groups claimed that a suicide mission had sabotaged the plane in retaliation against the United States. However, sabotage was later dismissed as a cause of the crash. The investigations were carried out by the U.S. National Transportation Safety Board and Mexican aeronautical authorities, who found that the cause of the accident was due to the center landing gear tire being filled with compressed air, instead of nitrogen. In addition, the tire had some marks of overheating. The investigators later found that the overheating was caused by a malfunctioning brake on the landing gear.
Mexicana maintenance personnel were blamed for negligence in maintaining the 727 and for filling the tire with regular compressed air, instead of nitrogen. The crash remains the deadliest airline disaster in Mexican history and is the world's worst air disaster involving the Boeing 727. The cause of the in-flight fire is believed to be the rupture of fuel lines by the exploding tire.
- "ASN Aircraft accident Boeing 727-264 XA-MEM Las Mesas". AviationSafety.net.
- Seiler, Michael (April 1, 1986). All 166 on Jet Die in Mexican Crash. Los Angeles Times
- Levi, Isaac A. (April 4, 1986). Mexican jet pilots claim plane crash caused by explosion. Kentucky New Era (AP).
- "Mexican jet crash was revenge for U.S. attack on Libya: note"
- The Montreal Gazette (AP), April 5, 1986.
- Fields, Dana (May 23, 1986). Explosion, fire preceded plane crash that killed 167. Nashua Telegraph (AP).