Indonesian LCC Lion Air has discovered cracks on two of its Boeing 737NGs, each aircraft having fewer than the 22,000 flight cycles stipulated by FAA’s threshold for inspection since cracks were discovered on other airline aircraft.

In late September, Boeing alerted operators of all 737NG variants that it had notified FAA of cracking on the left and right-hand side outboard chords of the station 663 frame fitting and failsafe straps.

Following the findings, FAA issued an airworthiness directive that came into effect in early October for high-time models above 30,000 flight cycles to be inspected within one week. Inspections on aircraft operating between 22,600 and 30,000 flight cycles were ordered to take place within a seven-month timeframe.

Hairline “pickle fork” cracks have been discovered on 737NGs operated by Brazilian carrier Gol, Korean Air, Irish LCC Ryanair, Southwest Airlines and Qantas.

Lion Air operates the 737-800 and 737-900ER, but it is not clear which type was affected. The aircraft have been grounded for repairs.  A Lion Air spokesperson told reporters that the inspections were carried out “to ensure security and safety of flights” even though they were not required.

Indonesia civil aviation authority director general Polana Pramesti told Indonesian reporters there were no plans to expand inspections beyond FAA’s stipulated cycles.

A Singapore Airlines spokesperson told ATW that inspections of SilkAir’s fleet of 14 737-800s fleet was ongoing, with no cracks discovered so far.

Chen Chuanren, chuanren@purplelightvisuals.com