Pilot Debrief

CIRRUS SR22T near Alexandria, MN — 2013-03-29

Final reportCEN13LA212
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Date
2013-03-29
Location
Alexandria, MN, USA
Airport
KAXN
Aircraft
CIRRUS SR22T
Registration
N1967N
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Approach

Probable cause

The failure of maintenance personnel to install a safety wire during reinstallation of the right flap, which led to the separation of the right flap rod from the right flap actuation fitting during flap extension. Contributing to the accident were inadequate inspections of the right flap during subsequent annual, prebuy, and preflight inspections.

NTSB narrative

About 18 months prior to the accident flight, the airplane underwent maintenance to remove and replace both the left and right flaps. While on pattern downwind, the pilot adjusted flaps from up to half, at which time the right flap rod end separated from the right flap actuation fitting. The pilot initiated a climb and struggled to maintain roll control. He briefly adjusted flaps to the up position in an attempt to alleviate the problem, and then adjusted the flaps back to half. The pilot then adjusted the flaps from half to full and the airplane began to roll right due to flap asymmetry, eventually reaching 86 degrees of right bank. The airplane began to stall and the pilot initiated the airplane’s ballistic parachute recovery system about 509 feet above ground level. Subsequently, the airplane descended to the ground with the aid of the parachute and came to rest upright on a frozen lake. A postflight examination of the right flap rod end area revealed the mounting bolt and washer were missing and lying under the airplane. No evidence of a safety wire was present on the mounting bolt or on the right flap actuation fitting. The safety wire was most likely not installed when the right flap was reinstalled and went unnoticed for over 211 hours of operation. During this time there was a subsequent annual inspection at 114 hours prior to the accident and a pre-buy inspection at 101 hours prior to the accident.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Properly securing the right flap during maintenance could have prevented the failure.

NTSB coding

Evidence available

  • 4 docket documents
View NTSB final reportView NTSB docket

Docket documents4

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