Pilot Debrief

BEECH C90 near Fort Worth, TX — 2010-06-03

Final reportCEN10LA302
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Date
2010-06-03
Location
Fort Worth, TX, USA
Airport
AFW
Aircraft
BEECH C90
Registration
N20
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Approach

Probable cause

The failure of the nose gear actuator due to insufficient lubrication of the nut assembly threads.

NTSB narrative

As the landing gear was extended, the flightcrew heard a loud "bang" and observed a “Gear Unsafe” indication. After making a low pass, tower personnel reported that the main gear appeared to be down but that the nose gear was only partially extended. The certificated flight instructor raised the landing gear and made another low pass. Tower personnel said the main gear was up, but the nose gear was still only partially extended. The flightcrew elected to return to their home base and land. As speed dissipated, the nose gear folded and the airplane slid to a stop. A postaccident examination revealed that the nose gear actuator had failed due to insufficient lubrication of the nut assembly threads. The manufacturer recommends that the actuator be overhauled or replaced every 8000 cycles, or 6 years, whichever occurs first. At this time, the screw and nut assembly is to be greased. The failed actuator had accrued 1,576 cycles and 951.2 hours time-in-service. The maintenance manual does not require in-service lubrication of landing gear actuator.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Crew could have opted for an emergency landing sooner after gear indication issues.

NTSB coding

Evidence available

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

Docket documents12

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