Earlier this week an American Airlines 757 en route from Miami to Boston lost cabin pressure prompting the crew and 154 passengers to don oxygen masks about half an hour into the flight. The aircraft then descended to a lower altitude from 31,000 feet, turned around and made a safe landing at Miami International Airport. There were no injuries.
It is now known that the cause of the decompression was a rupture roughly two feet long and a foot wide above the aircraft’s front left cabin door
The American aircraft is now out of service. Its flight-data and cockpit voice recorders have been shipped to the safety board, which also will examine the ruptured portion of the fuselage.
A spokesman for American Airlines confirmed details of the incident on Thursday, adding that airline engineers and technicians are cooperating with government safety officials to determine the cause.
Based on initial reports, the spokesman said, the pressure loss inside the cabin started "with a small hole in the fuselage just above the first door on the left side" of the plane behind the cockpit, and then ripped open a gash two feet long.
This scare is significant because it is very similar indeed to cracks found last month in the fuselage of a United 757. Investigators are now looking for links between Tuesday's American Airlines incident and the damage found on the United aircraft. Moreover both aircraft have flown between 20,000 – 25,000 flights so they are in the same age bracket which could indicate a metal fatigue problem on older 757 aircraft.
Boeing is now working on a safety alert (service bulletin) dealing with stepped-up inspections of certain portions of older 757 models while they provide technical assistance to both the FAA and the NTSB, the latter two regulators are likely to issue a mandatory directive before long.
Whenever an aircraft type comes under investigation airlines have no choice but to sit up and take note. American Airlines alone operates a fleet of more than 100 Boeing 757s. The last time we had an incident of this type, in 2006 involving an older 737 of Southwest Airlines, all aircraft in the global fleet had to undergo checks. Owners and operators of middle aged 757s beware and take note; additional costs are on the horizon.