Qantas has grounded three of its Boeing 737NGs for repairs after finding hairline cracks in a part of the aircraft that helps bind the wing to the fuselage.

The Australian flag carrier said in a statement today that it has completed precautionary inspections of thirty-three B737NG aircraft, checking for hairline cracks that have appeared in some high cycle aircraft worldwide.

The cracks relate to the “pickle fork” structure, which is located between the wing and fuselage. Qantas brought forward these precautionary checks by up to seven months and completed them within seven days.

Of the 33 of Qantas’ B737NG aircraft that required inspection, three were found to have a hairline crack in the pickle fork structure, the airline said. These aircraft have been removed from service for repair.

The aircraft had all completed around 27,000 cycles. Any aircraft with more than 22,600 cycles was inspected, in line with advice from regulators, Qantas added.

Qantas said it will “minimise any customer impact from having these aircraft temporarily out of service”.

The airline is working with Civil Aviation Safety Authority and Boeing to resolve this issue, which involves some complex repair work. Qantas expects all three aircraft to return to service before the end of the year.

CEO of Qantas Domestic, Andrew David said: “As people would expect with Qantas, we’ve gone above what was required to check our aircraft well ahead of schedule.

“We would never fly an aircraft that wasn’t safe. Even where these hairline cracks are present they’re not an immediate risk, which is clear from the fact the checks were not required for at least seven months.”

Qantas said it will continue to monitor aircraft that are in scope of the airworthiness directive as inspections fall due.

Impact on other airlines

The issue of picklefork cracks is not limited to Qantas. Cracks have been found in up to 50 737NGs globally, according to Agence France-Presse (AFP). Boeing had previously reported a problem with the model’s pickle fork, prompting US regulators to order immediate inspections of aircraft that had seen heavy use.

The news agency cited a Boeing executive as saying that so far about 1,000 aircraft worldwide had “reached the inspection threshold”, with less than five per cent – or up to 50 aircraft globally – having “findings” that kept them grounded until repair.

AFP added that American Airlines and United Airlines were also inspecting their entire fleets but had not found any pickle fork issues so far. Virgin Australia said it had already inspected all 19 of its B737NGs with more than 22,600 cycles and did not find any cracks.

Reuters said Southwest Airlines in the United States had removed three B737NGs from service for pickle fork repairs.

“I think the timing is unfortunate [for Boeing], but to be honest I’m not 100 per cent certain that it’s as big a deal as it is being made out in the media. Planes fly around with cracked structure all the time,” an Asia-based aircraft engineer, who declined to be named, told Business Traveller Asia-Pacific.

“The pickle fork is primary structure*, so it is obviously a concern, but I’m not sure if the media are just jumping on everything Boeing related at the moment on account of the Max.”

Boeing’s B737 Max, the successor to the B737 NG, has been in the media spotlight in recent days as senior executives from the company testify on Capitol Hill about aviation safety and the Max.

Business Traveller Asia-Pacific recently reported comments from a senior aircraft leasing company executive who said that the B737 Max will be the “safest aircraft in the world” when it returns to service.

A different executive, speaking at the same industry conference, said the Max’s global grounding has no historic precedent, comparing it with the grounding of the DC-10 in the 1970s and the more recent grounding of Boeing’s Dreamliner.

*”Primary structure” is that structure which carries flight, ground, or pressurisation loads, and whose failure would reduce the structural integrity of the airplane, according to the Federal Aviation Administration.