May 27 (UPI) -- A Delta Air Lines Boeing 717, which made an emergency landing two years ago and skidded "nose down" at North Carolina's Charlotte-Douglas International Airport, could not lower its landing gear because of a fractured support piece, the National Transportation Safety Board revealed in its final report Tuesday.
The NTSB announced it had found a metal fatigue crack in the upper lock link, one of the aluminum supports for the landing gear.
"The appearance of the scratch features was consistent with tool marks such as from filing or grinding operations," the NTSB said. "These scratch features likely acted as stress concentration areas for crack initiation."
According to the NTSB, Boeing and McDonnell Douglas issued an alert in 2001 to inspect all landing gear parts for rough surfaces. The upper lock link that failed in 2023 shows it had been inspected and overhauled in 2009. But, the NTSB said the overhaul by Israel Aerospace Industries did not fully comply with Boeing's service bulletin. That same upper lock link was moved five years later to the impacted Delta Boeing 717, where it remained until it ultimately cracked after 41,257 flights.
In response to the NTSB's findings, Boeing issued a new Alert Service Bulletin and more rigorous inspection requirements. No additional cracks have been reported on the Boeing 717 fleet.
