Pilot Debrief

NORTH AMERICAN AT-6D near Fredericksburg, TX — 2022-04-30

Final reportCEN22LA187
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Date
2022-04-30
Location
Fredericksburg, TX, USA
Airport
T82
Aircraft
NORTH AMERICAN AT-6D
Registration
N29947
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Initial climb

Probable cause

A total loss of engine power due to a failure of the No. 1 cylinder.

NTSB narrative

The pilot stated that he completed a preflight inspection and engine run-up with no anomalies noted. During the initial climb after takeoff, immediately after retracting the landing gear, the pilot noticed white smoke from the engine cowling. A few seconds later, the engine “coughed loudly” and lost total power. The pilot landed the airplane on the remaining runway; however, the airplane exited the runway and collided with a runway light. resulting in substantial damage to the left wing and left aileron. Federal Aviation Administration (FAA) inspectors completed an examination of the airplane and assisted the owner’s mechanics with removing the engine for transport. They discovered that the No. 1 cylinder was cracked around its circumference. They did not observe any other anomalies during the examination. Postaccident engine examination confirmed that the No. 1 cylinder head fractured near the rear spark plug on the exhaust side. The mechanic noted it was likely that during the accident takeoff, the cylinder head separated due to pre-ignition or detonation stresses, which no longer allowed the push rods to operate the valves and resulted in a loss of engine power. A recurring FAA airworthiness directive (AD) was applicable for this airplane and related to visual inspections to prevent cylinder head cracking. The AD was completed 164.7 flight hours before the accident and was due to be completed again in 85.3 hours.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Performing more thorough inspections on the engine before the flight.

NTSB coding

Evidence available

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

Docket documents5

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NORTH AMERICAN AT-6D near Fredericksburg, TX — 2022-04-30 · Pilot Debrief