JAKARTA • Lion Air has found structural cracks in two Boeing 737 NG planes that have clocked fewer flights than the US Federal Aviation Administration's (FAA) threshold for checks, Indonesia's aviation safety regulator said yesterday.
The discovery could make it more likely that the FAA will require airline operators to inspect 737 NGs with fewer than 22,600 cycles, something it had not mandated previously. Each cycle typically represents one flight, with a take-off and a landing.
The cracks are on what is known as the "pickle fork", a part that attaches the plane's fuselage, or body, to the wing structure.
An FAA spokesman said the agency had asked operators to report any cracks so it could assess whether it needed to change its inspection orders.
The Lion Air jets with cracks had fewer than 22,000 cycles and are now grounded for repairs, a spokesman for the airline said.
The carrier performed the checks even though they were not yet required to "ensure security and safety of the flights", he said.
Indonesia's director-general of civil aviation Polana Pramesti yesterday said there were no plans as yet to expand the inspections beyond the FAA directive.
The US aviation authority requires immediate checks of aircraft with more than 33,000 cycles and inspections within the next 1,000 cycles for those with more than 22,600 cycles.
Boeing did not respond to an immediate request for comment.
The manufacturer last week said that just over 1,000 planes globally had met the threshold for inspections to date, and of those, fewer than 5 per cent had issues.
Southwest Airlines, Brazil's Gol Linhas Aereas Inteligentes, Australia's Qantas Airways and Korean Air Lines are among the carriers that have grounded planes after discovering cracks.
One of Lion Air's newer 737 Max jets crashed last October, shortly after take-off from Jakarta, killing all 189 people on board and leading to heightened scrutiny over the carrier's maintenance operations by Indonesia's safety regulator.
Another Max jet operated by Ethiopian Airlines crashed in March, killing 157 people.
Boeing has been reeling since all 400 of its 737 Max jets were grounded in March following the two incidents. The international suspension has cost Boeing billions of dollars and forced it onto the defensive over its safety record.
Boeing's embattled boss Dennis Muilenburg said on Thursday that he had considered stepping down in the wake of the two crashes but vowed to stay on.
The accidents "happened on my watch, and I feel obligated, I feel responsible to stay on it, work with the team to fix it, to see it through", Mr Muilenburg told a conference in New York.