ERA23FA357 · Robinson Helicopter R22 BETA

The pilot was receiving flight training in the helicopter to upgrade his certificate level, and the accident flight was his second solo flight in the helicopter. The pilot’s flight instructor described that the purpose of the flight was to practice approaches to landing in the airport traffic pattern, but for reasons unknown, the pilot departed the airport traffic pattern, climbed to 1,200 above the ground and flew for about 1/2 mile before making a 180° turn. The helicopter continued for several miles before turning towards a nearby river. An eyewitness who was located on the dam of the river was photographing wildlife with a telephoto lens and observed the helicopter flying erratically towards her. Seeing this, captured photographs of the helicopter and accident sequence. As the helicopter approached, it was in a nose-down attitude, then leveled off. Shortly thereafter, the helicopter began a series of counterclockwise rotations and a series of aggressive pitch and roll changes before the main rotor blades contacted the tail boom. The tail rotor assembly was severed and the helicopter subsequently descended and impacted trees, terrain, and water. The tail rotor assembly was not located after exhaustive searches by multiple parties. The witness photos showed the pilot was bent forward at the waist to the point where his head was touching the helicopter’s windscreen. His arms were visible in several photos, but it is unknown if he was manipulating the controls. He remained leaning forward leading up to and after the loss of the tail boom. His hands and feet, and any associated control inputs to the cyclic, collective, or rudder were not observed. Postaccident examination of the engine, airframe, and systems did not reveal evidence of any preimpact mechanical malfunction or failure that would have precluded normal operation of the engine or airframe. However, with the loss of the tail rotor assembly, a mechanical failure of that system could not be ruled out. In addition, nothing was found indicating a mechanical or foreign object jam of the anti-torque pedals. Toxicological testing yielded negative findings but an autopsy was not performed. Although it is reasonable to consider that an incapacitating medical event might have occurred based on the photographic evidence, such an event is neither supported nor excluded by limited available medical evidence. With the lack of available evidence to support a mechanical failure combined with the lack of medical evidence supporting pilot incapacitation, the cause of the erratic maneuvering leading up to the main rotor blade contact with the tail boom could not be determined.

Verbatim NTSB analysis and probable cause from the NTSB dataset