Address Fatigue Cracks Of The NLG End Caps On The Airplanes
The NTSB has sent a letter to Hawker Beechcraft President and CEO Robert S. (Steve) Miller that recommends actions to be taken following a nose gear incident involving a Beech 1900D which occurred May 17, 2011.
On that date, a Beechcraft 1900D sustained minor damage when the left main landing gear collapsed on landing at Denver International Airport. There were no injuries associated with the incident.
In its probable cause report, the NTSB determined that the collapse was the result of fatigue failure of the Nose Landing Gear (NLG) end cap, which resulted in insufficient hydraulic pressure to secure the left MLG in the down-and-locked position.
The NLG end cap had accumulated a total of 29,533 cycles since it was manufactured, and was overhauled in 2008.
As a result of the incident, HBC changed it recommended maintenance practices for the NLG actuator. The board is currently investigating two similar incidents.
The NTSB said in its letter that it recommends that HBC determine the fatigue life of the 1900D nose landing gear end cap with the longitudinal grain direction both aligned and not aligned with the longitudinal axis of the NLG. It further recommends that the company develop and implement a replacement program for all 1900D NLG end caps based on that fatigue life determination, and revise the NLG end cap repetitive inspection procedure and time interval to ensure that fatigue cracks are detection prior to failure, and issue updated guidance to owners and operators regarding those inspections.