Robinson R22 BETA N4052K

Summary

On 2 July 2001 at about 21:26 local time, a Robinson R22 BETA registered N4052K, operated by Sierra Academy of Aeronautics, Inc., was involved in an accident near Hayward, California, United States. 2 people were on board and 2 had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

2 July 2001 at 21:26

Classification

Accident

Location

Hayward, California, United States

Nearest airport

Hayward Executive (HWD)

Coordinates

37.6594, -123.1817

Aircraft

Robinson R22 BETA

Registration

N4052K

Category

Helicopter

Engines

1

Operator

Sierra Academy of Aeronautics, Inc.

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Oakland → Hayward

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

LAX01LA232

2 people had minor injuries.

the student's excessive rate of descent during a practice autorotation, and, the inadequate use of the rotorcraft flight controls by both pilots during the attempted recovery, which resulted in a hard landing. The flight instructor's inadequate supervision during the maneuver was also causal.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The helicopter impacted the ground, bounced, and impacted the ground a second time during a practice autorotation. The commercial/student pilot was practicing a 180-degree autorotation with a power recovery when an excessive rate of descent developed. The flight instructor said he "joined" the student on the controls and initiated a progressive rollout of the turn while simultaneously applying aft cyclic, raising the collective, and applying more power for a power recovery to level flight. The instructor said that the engine did not respond to the throttle input. Due to the rate of descent, the flight instructor elected not to attempt an "aggressive" flare "fearing a tail rotor ground strike." He continued with aft cyclic input and collective manipulation to reduce forward airspeed and rate of descent for a run-on landing. The helicopter contacted the ground in a "near skids level attitude" approximately 30 knots, with the rotor rpm in the "high end of the green region." The helicopter became airborne approximately 8-10 feet above the ground. The flight instructor indicated that the throttle was still unresponsive. He raised the collective to cushion the second impact and the low rotor rpm warning light and horn came on prior to set down. The helicopter impacted the ground again approximately 20 knots, collapsing the left skid. The helicopter then rolled to the left and came to rest on its left side facing approximately 180 degrees from the approach heading. A post-accident examination of the helicopter revealed no anomalies, with the exception of a failed left seat restraining system. An engine test run was conducted and no anomalies were noted that would have affected its operation.

Quoted verbatim from the NTSB record.