Beech 1900D N195GL accident near Denver, Colorado

Probable cause

The pre-existent damage of the right-hand landing gear actuator attachment lug which led to fatigue cracking and eventual overload failure resulting in a collapsed gear upon landing.

NTSB analysis

When the crew retracted the landing gear after takeoff, they heard a loud "bang." When they lowered the gear, all three landing gear annunciator lights indicated SAFE, but the left gear light also indicated IN TRANSIT. After consulting with their maintenance department, the crew landed and, during rollout, the left main gear collapsed. Postaccident examination revealed the drag leg assembly was fractured. When the gear collapsed, a portion of the wing spar was torn out. Metallurgical examination revealed that both lugs that attach to the landing gear actuator and the rig plate were fractured and the drag leg was bent. The right-hand lug contained a fatigue crack that progressed to an overload failure. The other lug fractured completely through overload. The damage was pre-existent to that cracking, and served as a stress concentrator leading to the initiation of a fatigue crack. Spectrographic analysis of the upper drag leg arm showed that it met specified chemical composition requirements. At time of accident the aircraft had operated about 82.9 hours and 95 cycles since a detailed inspection of the landing gear was accomplished on May 28, 2010; no discrepancies related to the lug were noted at that time.

Text from the NTSB. Open the NTSB docket for CEN10LA315 for the full record.