Pilot Debrief

BEECH 99 near Waterville, ME — 2020-10-14

Final reportERA21LA021
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Date
2020-10-14
Location
Waterville, ME, USA
Airport
WVL
Aircraft
BEECH 99
Registration
N499CZ
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Landing

Probable cause

A failure of the right main landing gear drag leg support fitting and angle bracket as a result of multiple areas of fatigue cracking.

NTSB narrative

While taxiing to the ramp, the airplane’s right main landing gear collapsed, resulting in substantial damage to the right wing. Examination of the right main landing gear drag leg support fitting and angle bracket revealed several areas of fatigue cracking with multiple origins. The attach angle bracket fracture exhibited features consistent with fatigue. The reason for the crack initiation could not be determined. A review of the maintenance procedures performed on the right main landing gear 8 days prior to the accident found that they instructed the mechanic to add grease to the drag leg fitting. The procedures did not specify to examine the landing gear for fatigue cracking or anomalies; therefore, it is unlikely that the mechanic would have looked in the area of the cracked main landing gear drag leg support fitting and angle bracket. Furthermore, there was no nondestructive testing procedures for examining the main landing gear drag brace, so it’s unlikely an inspection would have detected the multiple areas of fatigue cracking.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Inspect landing gear for fatigue cracks during maintenance.

NTSB coding

Evidence available

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

Docket documents8

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