Loss of Control in Flight · NTSB CEN14LA305

BOLLINGER ROBERT L BD 4 — Fairfield, IA

1 fatal Low altitude
DateJune 22, 2014
LocationFairfield, IA
AircraftBOLLINGER ROBERT L BD 4 (amateur-built)
Purpose of flightPersonal
ConditionsDay · Visual Meteorological Cond
Phase / occurrenceManeuvering Loss of control in flight
Pilot age64
Pilot total time480 hrs · Building experience
Time in type400 hrs
Fatalities1

Probable cause

The pilot’s loss of airplane control due to the in-flight separation of the propeller blades for reasons that could not be determined based on the available evidence.

NTSB findings

  • Aircraft-Aircraft propeller/rotor-Propeller system-Propeller blade section-Failure - C
  • Not determined-Not determined-(general)-(general)-Unknown/Not determined - C

What happened

A witness reported seeing the airplane take off, make a 90-degree left turn, descend, and subsequently collide with terrain about 600 ft east of the runway. A postimpact fire ensued. During the examination of the accident site, all of the airplane's structure was found except for the propeller blades. The day after the accident, the airport manager found two of the three propeller blades while he was mowing grass. Photographs of the two propeller blades showed damage consistent with the in-flight separation of the blades. Neither blade exhibited impact or thermal damage. The breaks at the hub were not bent but pulled straight out. The reason for the in-flight separation of the propeller blades could not be determined.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.

View the official NTSB docket →