Qantas Airways Ltd. grounded three Boeing Co. 737s after discovering cracks near their wings during industry-wide inspections of high-mileage models of the workhorse jets.

The Australian airline found hairline cracks on a structure known as the pickle fork, which connects the wings to the fuselage. The planes will be back in service by the end of the year, Qantas said in a statement Friday.

The U.S. Federal Aviation Administration last month ordered urgent checks on next-generation 737s that have carried out more than 30,000 flights, while aircraft with more than 22,600 flights needed less-immediate inspections. Qantas, which has a fleet of more than 300 planes, had to inspect 33 of its 75 next-generation 737 jets — none of them immediately.

Globally, about 5% of aircraft that required urgent checks had cracks, Boeing said last month. The U.S. manufacturer has already been under heavy scrutiny after 737 Max planes crashed in Indonesia and Ethiopia, killing a total of 346 people and leading to a worldwide grounding of those jets. Boeing Chief Executive Officer Dennis Muilenburg faced fierce questioning from lawmakers in Washington this week.

Qantas shares were up 1% to A$6.48 at 11:50 a.m. in Sydney.

The cracks are around the same place on each of the Qantas jets, close to one of eight bolts on the pickle fork, the airline’s head of engineering, Chris Snook, said at a press conference. The structure’s load-bearing ability hasn’t been compromised, he said. Passenger disruption will be minimized, the airline said.

Qantas Rejects Call to Ground 737s as Union Says 2nd Jet Cracked

There are about 6,800 next-generation 737 jets in service around the world, including lower-mileage aircraft that don’t fall under the FAA’s directive.w