Reuters/Atlanta/Washington

The 5-ft-long fuselage skin section taken from the Southwest Airlines accident aircraft is displayed to the media at the National Transportation Safety Board (NTSB) in Washington, DC, yesterday

Boeing Co will recommend that airlines throughout the world check older 737 aircraft for the kind of fatigue cracks that prompted Southwest Airlines Co to cancel hundreds of flights.
The manufacturer said in a statement on Monday it is preparing a service bulletin for targeted fuselage inspections of 737-300s. More than 900 are in service around the world, but the directive will only apply to more heavily used aircraft.
Southwest voluntarily launched checks of more than 100 of those models after one landed in Arizona on Friday with a hole in its fuselage.
The airline cancelled 600 flights over the weekend and 70 on Monday. More than half of the planes grounded for inspections have returned to service. Subsurface fuselage cracks were found on three.
Analysts expect some lost revenue, but no lasting fallout financially from the disruption, which comes as Southwest works to close its buyout of AirTran Airways, a unit of AirTran Holdings Inc.
“I don’t think there is anything systematic or persistent here,” said James Higgins, an analyst with Soleil Securities. “This is more noteworthy for its headline generation than for its likely damage to the company.”
Southwest led a mostly negative trading day for US airlines, but pared its losses and was off 2.3% to $12.37 on the New York Exchange.
Flight 812 was heading from Phoenix to Sacramento when a 5-ft (1.52m) tear opened in the fuselage 20 minutes after takeoff on Friday.
A similar incident occurred two years ago and Southwest paid a $7.5mn Federal Aviation Administration fine for operating 737s without required fuselage structural inspections in the 2006-07 timeframe.
Robert Herbst, an independent airline analyst and founder of AirlineFinancials.com, said Southwest has more take-offs and landings per aircraft than other carriers, putting wear and tear on its planes.
“The industry itself has to replace some of these old aging aircraft,” Herbst said.
Still, he said Southwest is one of the world’s safest airlines, noting it has never had a fatal crash.
Southwest said over the weekend its fleet regularly undergoes “rigorous checks and inspections” as directed by the FAA and Boeing. These checks and inspections are partly dictated by number of takeoffs and landings.
The narrow-body 737 is Boeing’s best selling model. There are about 280 737-300s currently in the US airline fleet and 900 globally.