NTSB investigating American Airlines Boeing 757 safety incident

The U.S. National Transportation Safety Board (NTSB) is investigating an incident that caused an American Airlines Boeing 757-200 aircraft to make an emergency landing after the cockpit filled with smoke. The incident occurred on January 30, 2008 while the aircraft, operating as American Airlines Flight AA 1738, was en route from San Juan, Puerto Rico to Philadelphia with 139 passengers and seven crew members on board. The crew declared an emergency and diverted to West Palm Beach, FL where the aircraft landed safely.

A preliminary report about the incident posted to the FAA website on February 1, 2008 noted that six individuals who had been on board the flight "were transported to the hospital with unknown injuries." The NTSB subsequently reported that the six who were hospitalized had suffered smoke inhalation. All six have been released from the hospital, and no other injuries were reported.

The NTSB has issued an advisory announcing the commencement of an investigation into the cause of this incident. This brief summary of the event was released:

According to reports from the crew, while at cruise altitude over the Atlantic Ocean, smoke began emanating from the window heating system connected to the first officer's windshield. The crew donned oxygen masks and smoke goggles and diverted to Palm Beach International Airport. During the descent to land, the inner pane of the first officer's windshield shattered. The crew continued the descent and landed without further incident.

The digital flight data recorder (DFDR) was downloaded and sent to the NTSB laboratories in Washington. The affected windshield, which remained in one piece, and the heating unit were removed from the aircraft and will undergo a detailed analysis.

The photo on this page, which shows the shattered windshield, was made available by the NTSB.

While the exact cause of this incident is still under investigation, the NTSB points out that "five events between 2004 and 2006 in which smoke, and in some cases fire, were reported to have originated from window heating systems in B-757 aircraft."

Based on these incidents, in September 2007 the NTSB issued two Safety Recommendations to the Federal Aviation Administration (FAA) asking the agency to require the installation of redesigned window heating systems in all Boeing 747, 757, 767, and 777 series aircraft. These Safety Recommendations have yet to be implemented by the FAA.

To read the full text of those Safety Recommendations, click here: NTSB Safety Recommendations A-07-49 and -50. (3 page 'pdf' file)

[Photo Source]

NOTE: For an interesting personal account (with photos) of a similar incident last year in which a B757 cockpit windshield shattered during cruise, read Pop Goes the Window, by an airline pilot who writes a blog called Captain's Log.