The first of Jin Air’s three Boeing 737NGs found with “pickle fork” cracks returned to service this week.

The first of Jin Air’s three Boeing 737NGs found with “pickle fork” cracks returned to service this week.

The Korean Air-affiliated carrier says that repair and replacement work, conducted jointly with Boeing, was completed on Monday and the aircraft was returned to service on Tuesday.

It tells Cirium that FAA and South Korea’s Ministry of Land, Infrastructure and Transport (MOLIT) had approved the outcome of the repair work after safety checks and test flights.

“We have two more B737 NGs with same problem and expect the repair to finish within this year,” it says.

The “pickle fork” is a piece of hardware which connects the wing to the aircraft fuselage. Cracking of the hardware could result in structural failure, which affects the structure integrity of the aircraft and results in loss of control.

Global regulators have urged airlines operating 737NGs with more than 30,000 flight cycles to inspect their aircraft immediately for cracks. Aircraft that have logged 22,600-30,000 cycles should be inspected within the next 1,000 cycles.

Last week, MOLIT identified 13 737NGs that contain cracks, after inspecting 100 737NGs. Nine of these were identified in a first round of inspection in October and had clocked more than 30,000 flight cycles.

MOLIT notified Boeing about the cracks, which then sent a team to South Korea on 31 October to commence repair work. It said it takes about two weeks to work on each aircraft and the affected aircraft will all be repaired by January 2020.

The ministry did not specify which airlines operated the affected 737NG aircraft, but local media reports state that besides the three from Jin Air, five were operated by Korean Air, three by Jeju Air and two from Eastar Jet.

The same reports indicate that Boeing’s team is working on the five 737NGs operated by Korean Air and two of three from Jin Air.