Pilot Debrief

BOMBARDIER INC CL-600-2B19 near Baton Rouge, LA — 2011-09-01

Final reportCEN11IA615
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Date
2011-09-01
Location
Baton Rouge, LA, USA
Airport
BTR
Aircraft
BOMBARDIER INC CL-600-2B19
Registration
N875AS
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Approach

Probable cause

The improperly installed upper attachment bolt in the left main landing gear uplock assembly, which led to the failure of the left main landing gear to extend before landing. Contributing to the accident was maintenance personnel's lack of training on the installation and inspection of the uplock assembly.

NTSB narrative

While configuring the airplane for landing, the flight crew observed a landing gear disagree message and an indication that the left main landing gear was not down and locked. The flight crewmembers followed procedures to address the landing gear disagree message; however, they were unable to get the left landing gear to extend. The captain declared an emergency and chose to land the airplane with only the right main landing gear and nose landing gear extended. The airplane came to rest in an upright, left-wing-low position. Postincident examination of the left main landing gear system revealed that the upper attachment bolt for the left main landing gear uplock assembly, which is designed to be attached to both the uplock mechanism and the structure, was attached only to the airplane structure. The left main landing gear uplock assembly had been removed and reinstalled the day before the incident flight. The mechanic who performed the maintenance did not have training on nor prior experience performing the installation of the uplock assembly, and the maintenance inspector who inspected its installation did not have training on inspecting the uplock assembly. Neither the mechanic nor the maintenance inspector observed any problems during the postinstallation inspection. Thus, it is likely that the uplock assembly was installed incorrectly due to the lack of training in both the installation by the mechanic and the inspection by the inspector.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Maintenance personnel should have been more experienced with uplock assembly installation.

NTSB coding

  • Landing gear not configured · Landing
  • Experience / Qualifications
  • Maintenance

Evidence available

  • CVR
  • 6 docket documents
View NTSB final reportView NTSB docket

Docket documents6

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