Southwest Airlines (WN, Dallas Love Field) has grounded two B737NG aircraft and GOL Linhas Aéreas Inteligentes (G3, Sao Paulo Congonhas) eleven units due to newly discovered structural cracks of the so-called pickle forks, a part connecting the wing to the fuselage, Reuters has reported.

The groundings resulted from inspections mandated by the Federal Aviation Administration on October 2, 2019. The authority ordered immediate inspections within seven days of all B737NG aircraft which have already accumulated at least 30,000 flight cycles. The remaining narrowbodies have to be inspected prior to the accumulation of 22,600 total flight cycles, or within 1,000 flight cycles after the effective date of the directive.

The FAA said at that time that urgent inspections were necessary for over 165 US-registered B737NGs.

Southwest Airlines said that while it did not find any issues with the "vast majority" of its B737NGs, it "removed the two aircraft from our operation and reported the findings to Boeing and the FAA" and will not reactivate them until the issues are removed.

According to the ch-aviation fleets advanced module, Southwest Airlines currently operates 511 B737-700s and 207 B737-800s. As of June 30, 2019, 226 -700s had over 30,000 flight cycles.

For its part, GOL operates twenty-three -700s and ninety-seven -800s. The airline said that it found "evidence of the need to replace a specific component, whose characteristics were not compliant with the standards set by the maker". Fifteen -700s and ten -800s had exceeded 30,000 flight cycles by the end of June 2019.

Boeing said that so far, cracks have been found in 38 aircraft globally out of 810 inspected units. No other airlines have so far reported groundings related to the issue.

ch-aviation fleets module shows that there are currently 395 active B737NGs operated by 32 carriers globally which have already exceeded the 30,000 flight cycle threshold (covering only carriers reporting utilisation to ch-aviation directly or via Boeing).