Pilot Debrief

Beech 1900D near Denver, CO — 2010-06-12

Final reportCEN10LA315
Sign in to save
Date
2010-06-12
Location
Denver, CO, USA
Airport
DEN
Aircraft
Beech 1900D
Registration
N195GL
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Initial climb

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 narrative

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.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Crew could have opted to land immediately after hearing the loud bang.

NTSB coding

Evidence available

  • Photos
  • 11 docket documents
View NTSB final reportView NTSB docket

Docket documents11

Related mishaps