After taking an almost $5 billion pretax charge following the 737 MAX controversy earlier this year, Boeing is facing fresh challenges as the FAA orders inspections to be carried out for 737NG structural cracks in the pickle fork – a critical structure that helps attach the plane’s wings to its fuselage.
The pickle fork on the 737 Next Generation is designed to last the lifetime of the airplane – some 90,000 flight cycles (takeoffs and landings). However, the 737NG structural cracks found in a pickle fork about a month ago, fairly early in the airplanes lifecycle, have now shown up in other airframes. The FAA has ordered inspections, following Boeing’s own report that they had found multiple instances of “severe” structural cracks in the pickle forks of 737NG aircraft.
The pickle fork is an important part of the system which deals with the stresses and forces that bend the connection between the aircraft’s wing and fuselage. Structural cracking of the pickle fork is highly unusual, and could lead to catastrophic consequences if the part fails during flight. It would therefore appear that the FAA’s caution is justified.
It would appear that the 737NG structural cracks are affecting a small number of the in-service fleet, but the full extent of the problem is not yet known. No in-flight issues have been reported at this stage.
The Boeing 737NG was launched in 1993 as the third-generation derivative of the ubiquitous 737 line of narrow body twin engine passenger jets. Over 7,000 of these aircraft have been delivered since its introduction to the market. You can read more about this aircraft type here.