• The aircraft manufacturer Boeing has discovered cracks in a vital part of its Boeing 737 Next Generation planes that connects the body of the aircraft to its wings, the Seattle-based KOMO News first reported.
  • Boeing discovered the “cracking issue” in a small number of planes, the company said in a statement.
  • The Federal Aviation Administration has ordered operators to inspect the planes for structural cracks.
  • Boeing’s website lists more than 100 airlines as customers of 737 NG planes.
  • The 737 Max, which was grounded in March after two fatal plane crashes, is not affected by this issue.
  • Visit Business Insider’s homepage for more stories.

The aircraft manufacturer Boeing has discovered a “cracking issue” in a vital part of its Boeing 737 Next Generation planes that connects the body of the aircraft to its wings, Charlie Harger at the Seattle-based KOMO News first reported.

The aircraft piece in question, known as a pickle fork, helps connect the plane’s body to its wings.

Pickle forks are designed to last the life of the plane, which is usually about 90,000 or more takeoffs and landings, the publication reported. But in one instance, Boeing found cracked pickle forks in a plane that had logged about 35,000 takeoffs and landings, according to KOMO.

The Federal Aviation Administration has ordered operators of 737 NG planes to inspect the aircraft for structural cracks, according to a statement shared with Business Insider.

Boeing reported the issue to the FAA after it discovered the cracks while modifying a "heavily used aircraft," according to the statement. The company said it found similar cracks in a small number of other planes, as well.

Boeing said in a statement that it had notified operators of the issue and that the planes with cracks were "undergoing modifications." No in-service issues had been reported, the company said.

Boeing's website lists more than 100 airlines as 737 NG customers, including American Airlines, Delta Airlines, EgyptAir, RyanAir, and Southwest Airlines. The 737 NG models include 737-700, 737-800, and 737-900 aircraft.

The 737 Max is not affected by the cracking issue, the company said.

That model was grounded in March after two fatal plane crashes.

Read more: The complete history of the 737 Max, Boeing's promising yet problematic workhorse jet