Pilot Debrief

CESSNA TR182 near Beloit, KS — 2018-06-18

Final reportCEN18LA230
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Date
2018-06-18
Location
Beloit, KS, USA
Airport
K61
Aircraft
CESSNA TR182
Registration
N756SW
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Maneuvering

Probable cause

The mechanic’s failure to properly torque one of the left brake caliper’s back plate attachment bolts while re-installing it during the annual inspection, which resulted in the left main landing gear not extending before landing.

NTSB narrative

The private pilot was practicing takeoffs and landings in the airport traffic pattern when the left main landing gear (MLG) failed to extend. He cycled the gear, but the left MLG still would not extend. He then attempted to manually extend the gear without success. The pilot subsequently executed an emergency landing on the turf runway. During recovery of the airplane, one of the left brake caliper's back plate bolts was found backed out. Scrape marks were present on the fuselage skin, consistent with contact from the extended back plate bolt. The MLG extension/retraction system and the emergency extension system both performed normally during postaccident examination. An annual inspection had been completed 6 days before the accident, and the airplane had accumulated a total of 3.2 hours since then. The mechanic that performed the inspection reported that the brake calipers were removed at that time and that the bolts had not been secured with safety wire after they were re-installed. Given the evidence, it is likely that the mechanic did not properly torque the left brake caliper back plate bolt after he re-installed it during the annual inspection, which allowed it to back out and led to the subsequent failure of the left MLG to extend. Although safety wire would have prevented the bolt from backing out, the airframe manufacturer's service manual was not consistent about whether to use safety wire. Regardless, the bolt would not have backed out if it had been tightened within the specified torque.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Securing brake caliper bolts with safety wire after annual inspection.

NTSB coding

Evidence available

  • 4 docket documents
View NTSB final reportView NTSB docket

Docket documents4

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