Southwest Airlines grounds two Boeing 737 NG planes with cracked critical part

SEATTLE -- Southwest Airlines confirmed Tuesday that two of their Boeing 737 NG planes have been grounded because of cracked critical equipment.

Late last month, KOMO News was the first to report that inspectors found cracks in a critical part of an 737 NG known as the pickle fork.

Following that report, last week, the FAA ordered emergency inspections, known as an "airworthiness directive," or "AD," to take place within seven days.

A pickle fork is the part that helps attach a plane's fuselage to its wing structure. It helps manage the stress, torque and aerodynamic forces that bend the connection between the wings and the body of the jet.

Engineers design pickle forks to last the lifetime of the plane, more than 90,000 landings and takeoffs, a term known as "flight cycles" in the aviation industry, without developing cracks. There could be dire results if the pickle fork system on the jet fails in flight.

Overall, around 500 of the planes from airlines around the world have been inspected for the issue.

Aviation analyst Scott Hamilton with the Leeham Company says 25 planes so far have been discovered with the cracking. "Simple mathematics says that's 5%," he said.

But he cautions against people getting too nervous about flying.

"You're still going to have more danger getting to the airport than flying on one of these airplanes," he said.

These latest groundings for the Southwest 737 NGs come as the airline struggles with a grounded 737 MAX fleet.

Those groundings have led to the cancellations of an estimated 30,000 Southwest flights since March.

The pilots's union, the Southwest Airlines Pilots Association, filed a $100 million lawsuit against Boeing over those groundings Monday, suing for back pay.

KOMO reached out to Southwest about the latest issue involving the inspections, and the cracks found on 737 NG, which have been busy flying passengers. A company spokesperson says:

"Southwest has completed all inspections of the high-cycle 737 Next Generation (NG) aircraft in compliance with the seven-day deadline specified in the FAA’s Airworthiness Directive (AD). During our inspections of the high-cycle NGs, we did not find abnormalities on the vast majority of our inspected fleet but did identify signs of cracking on two aircraft. Southwest removed the aircraft from our operation and reported the findings to Boeing and the FAA. The aircraft will remain out of our schedule until the maintenance items have been fully resolved, and we do not have a return to service timeline for the aircraft. Safety is always our uncompromising priority, and our Technical Operations Team is now focused on completing inspections on the remaining portion of the NG fleet covered by the AD."

The pickle fork problem was first discovered on a passenger plane being converted to a cargo jet for Amazon Prime.

Though the first batch of inspections is complete -- many more will need to be done worldwide in the coming weeks and months.