The FAA has issued an AD concerning the cracking found on several 737 NGs where the wing is attached to the fuselage in a part commonly referred to as the pickle fork. Here is what the AD states:
“This AD requires repetitive inspections for cracking of the left and right hand side outboard chords of frame fittings and failsafe straps at a certain station, and repair if any cracking is found. This AD was prompted by reports of cracking discovered in this area. The FAA is issuing this AD to address the unsafe condition on these products…”
“In September 2019, the FAA received reports of cracking discovered in the left and right hand side outboard chords of the station (STA) 663.75 frame fittings and failsafe straps adjacent to the stringer S-18A straps on multiple Boeing Model 737-800 airplanes during a passenger-to-freighter conversion. The affected airplanes had accumulated between 35,578 and 37,329 total flight cycles. Cracking in t he STA 663.75 frame fitting outboard chords and failsafe straps adjacent to the stringer S-18A straps, if not addressed, could result in failure of a Principal Structural Element (PSE) to sustain limit load. This condition could adversely affect the structural integrity of the airplane and result in loss of control of the airplane.”
See the entire AD here.