An inspection of nearly 700 older Boeing 737 NGs found cracks in the wing supports of 36 planes, according to USA Today.
The figure represents about 5 percent of 686 planes checked for cracks in following an order by the Federal Aviation Administration (FAA). Southwest Airlines will have to take two planes out of service for repairs following the inspection, while Brazil’s Gol Linhas Aereas was far harder hit and forced to ground 11 planes, according to Reuters.
The cracks, if not addressed, could “adversely affect the structural integrity of the airplane and result in loss of control of the airplane,” the FAA said in the inspection order, which applied to only some of the most heavily flown planes.
“Boeing regrets the impact this issue is having on GOL, as well as our 737 NG customers worldwide,” the company said in a statement, according to USA Today.
“We are actively working with our customers with inspection findings to procure parts, develop repair and replace plans, and provide all the technical support needed to safely return every impacted airplane to service as soon as possible,” Boeing added.
The NG, or Next Generation, was an earlier version of the more commonly used 737. Southwest has a fleet of about 700 NGs, while American Airlines has 304 and Delta Air Lines has 200, according to USA Today.
The discovery is another setback for Boeing amid efforts to get its 737 MAX model back in the air after it was grounded following two recent crashes that collectively killed 350 people. A union representing Southwest pilots sued the company earlier in October, seeking to hold the company responsible for lost wages due to the grounded MAX.