U.S. investigators probe in-flight hole in passenger jet

July 18, 2009 Investigators with the United States National Transportation Safety Board (NTSB) are examining a damaged section removed from a Southwest Airlines Boeing 737-300 that blew out in-flight on Monday, July 13.

The passenger jet was flying between Nashville, Tennessee and Baltimore, Maryland when the hole, which measured seventeen inches by eight, opened up in the jet's roof. A safe emergency landing was performed and the 126 passengers were evacuated from the aircraft without injury.

The damaged section arrived in Washington, D.C. yesterday for examination by the NTSB. They have reported that there is no corrosion or obvious pre-existing mechanical damage to the segment.

As a result of the incident Southwest have inspected all 180 of their Boeing 737-300s, without result, within 24 hours of the incident. Continental Airlines have done likewise to their own examples of the type.

In 2008, Southwest was fined after it was found to have operated 47 jets that were overdue for inspections. In the light of Monday's incident, former NTSB member and maintenance specialist John Goglia criticized the airline's maintenance practices and governmental oversight. "Where's the maintenance programs with this airline? Where's the FAA (Federal Aviation Administration)? Where's the oversight? I mean, the list goes on and on. These people on this airplane really don't know how lucky they were." Southwest released a statement the day after the mishap in defense of their maintenance. "Southwest Airlines has an exemplary safety record that always is our focus. We are actively engaged with the NTSB in finding the cause of this incident and assuring that it does not happen again. We applaud our pilots and flight attendants for their expert handling of this situation and our customers for their cooperation."

The inspections Southwest failed to perform in 2008 concerned examining the top of their aircraft for structural damage after a weight reducing modification was discovered which could reduce the strength of the design. NTSB spokesman Peter Knudson said that "It looks like that (Airworthiness Directive (AD)) would apply [to Monday's incident]. We are going to look at the maintenance records and the maintenance practices, and we are going to want to know if all of these (ADs) were followed."

However, the FAA said that the inspections did not apply to the section that failed and, in any event, Boeing and Southwest ultimately came up with an improved design that was up to standard.