Event CEN22LA187

Factual narrative

On April 30, 2022, about 1300 central daylight time, a North American AT-6D airplane, N29947, was substantially damaged when it was involved in an accident at Gillespie County Airport (T82), Fredericksburg, Texas. The pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. 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 During the initial climb after takeoff, immediately after the landing gear was retracted, the pilot noticed white smoke from the engine cowling. A few seconds later, the engine “coughed loudly” and then lost total power. The airplane was still over the runway, and the pilot extended the landing gear, then retracted it again when he realized that insufficient runway remained for landing. The airplane landed with the right main gear extended and the left main gear partially extended, exited the runway, and collided with a runway light. The airplane sustained substantial damage to the left wing and left aileron. FAA inspectors completed an examination of the airplane and assisted the owner’s mechanics with removing the radial engine for transport. They discovered that the No. 1 cylinder was cracked all the way around the 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. A review of the airplane maintenance records revealed that an annual inspection was completed on April 27, 2022 (3 days before the accident), at an aircraft total time (TT) of 11,694.0 hours. The previous annual inspection was completed on January 28, 2021, at 11,680.3 hours TT. A recurring FAA airworthiness directive (AD) 99-11-02, was applicable for this airplane and related to visual inspections to prevent cylinder head cracking. The AD was completed on June 29, 2017, at 11,529.3 hours TT. The AD was due to be completed again 250 hours later, at 11,779.3 hours TT. 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. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12

NTSB Findings

Hierarchical cause / factor breakdown from the FAA bulk avdata database. Each finding tagged C (Cause) or F (Factor).

• — Aircraft-Aircraft power plant-Engine (reciprocating)-Recip eng cyl section-Failure