Event WPR18LA124

Factual narrative

On April 20, 2018, about 1700 eastern daylight time, a Piper PA-34-220T, N8404B, was substantially damaged when it was involved in an accident near Clewiston, Florida. The airline transport pilot and three passengers were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that, following an uneventful flight, he intended to practice landings at the destination airport. After a full-stop landing, the pilot taxied back to the end of the runway for another takeoff and remained within the traffic pattern with the intent of conducting a touch-and-go landing. After touching down on the runway, he retracted the flaps and advanced both throttles to takeoff power. Shortly after, he felt the airplane yaw to the right, observed an overboost indicator light for the right engine, and lost control as the airplane exited the right side of the runway. The pilot said that he regained control of the airplane when it entered the grass. He reduced both engines to idle power to stop the airplane; however, it impacted the edge of a crossing taxiway and briefly became airborne before landing on the opposite side of the taxiway. The landing gear collapsed, and the airplane came to rest upright, resulting in substantial damage to the fuselage and right wing. The pilot-rated passenger, who was seated in the front right seat, reported that the airplane touched down slightly to the right side of the runway centerline. He observed the pilot retract the flaps and immediately push both throttles to the "wall." Both engines spooled up rapidly and both [engine] overboost lights came on. Examination of both engines, including their respective turbochargers, overboost valves, and wastegates, revealed no evidence of mechanical anomalies or malfunctions that would have precluded normal operation. A complete report of the engine examinations is in the public docket for this accident. The pilot was performing touch-and-go takeoffs and landings in the airport traffic pattern. After touching down, the pilot retracted the flaps and advanced both throttles to takeoff power. Shortly thereafter, he felt the airplane yaw to the right, observed an overboost indicator light for the right engine, and the airplane exited the right side of the runway. The pilot said that once the airplane was in the grass, he regained control of the airplane and reduced both engines to idle power; however, the airplane impacted the edge of a crossing taxiway and briefly became airborne before landing on the opposite side of the taxiway, resulting in substantial damage. Postaccident examination of the airplane did not reveal any evidence of any preexisting mechanical malfunction of the engines or turbocharger systems that would have precluded normal operation. The circumstances of the accident are consistent with the pilot's failure to maintain directional control following an inadvertent overboost of the right engine during takeoff.  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).

• C Personnel issues-Task performance-Use of equip/info-Use of equip/system-Pilot - C
• C Aircraft-Aircraft power plant-Turbocharging (recip only)-Turbocharger-Capability exceeded - C
• C Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot - C
• — Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Directional control-Not attained/maintained