Qantas has pulled three its Boeing 737 fleet from service after finding hairline cracks in the "pickle fork" structure between the wing and the fuselage.
"These aircraft have been removed from service for repair," Qantas said in a statement on Friday.
Qantas earlier this week found one example of cracking in an aircraft with just under 27,000 cycles and identified the other two during an audit of 33 of its 75-strong Boeing 737 fleet.
"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 said in a statement on Friday morning.

Qantas has pulled three its Boeing 737 fleet from service after finding hairline cracks. Source: AP
The carrier said all three planes would return to service by the end of the year.
The US Federal Aviation Administration earlier this month ordered airlines to check any 737s that had completed more than 30,000 take-offs and landings, known as cycles, for cracks.
"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 Domestic chief executive Andrew David said.
The Australian Licenced Aircraft Engineers Association again called for the immediate grounding of all 75 Boeing 737s until inspections of the entire fleet were undertaken.
"We say these things for the safety of the people who fly on these aircraft," ALAEA federal secretary Steve Purvinas told ABC radio on Friday.
Mr Purvinas also took a swing at the Civil Aviation Safety Authority, which declared on Thursday there was "no evidence" the whole Qantas fleet should be grounded.
"CASA are nothing more than a PR department of Qantas operation," he said.

Qantas Group CEO Alan Joyce. Source: AAP
The union leader also criticised Boeing for outsourcing work in the United States.
"I don't have any confidence in Boeing at all," Mr Purvinas said.
"They're being very optimistic if they think these aircraft will be back in the sky by the end of the year."
But Qantas head of engineering Chris Snook criticised the ALAEA's remarks, saying they were "completely irresponsible".
"Even when a crack is present, it does not immediately compromise the safety of the aircraft," Mr Snook said.
Virgin Australia says it has already inspected 19 of its Boeing 737s and no cracks were found.
With AAP...