Robinson R22 N796SH

Summary

On 15 September 2009 at about 02:06 local time, a Robinson R22 registered N796SH, operated by NU Vista Aviation LLC, was involved in an accident near Irvine, California, United States. 2 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

15 September 2009 at 02:06

Classification

Accident

Location

Irvine, California, United States

Coordinates

33.6808, -117.7042

Aircraft

Robinson R22

Registration

N796SH

Category

Helicopter

Engines

1

Operator

NU Vista Aviation LLC

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Chino → Chino

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR09CA448

Nobody was injured.

The flight instructor's failure to maintain an adequate airspeed and his delayed recovery action during the practice autorotation, which resulted in a hard landing.

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

Read the full NTSB narrative

The flight instructor informed the private helicopter pilot under instruction (PUI) that the purpose of the practice autorotation was to demonstrate ways in which to reach a suitable landing zone in the event that an engine failure were to occur in an area with limited landing zones. The intention was to focus on the glide with a power recovery before the need to flare. The instructor entered the autorotation while the PUI observed. The instructor was demonstrating s-turns, beginning with a right 90-degree turn, followed by a left 180-degree turn, and ending with a right 90-degree turn to bring the helicopter back to the original heading. The rotor rpm remained in the green arc or above during the entire maneuver. During the last right 90-degree turn, the helicopter passed through what the instructor estimated to be 200 feet above ground level (agl), where he decided to discontinue the autorotation due to insufficient airspeed (40 KIAS), and a higher than expected rate of descent, which lead to a lower than anticipated height above ground. During the time it took for the instructor to decide to abort the autorotation, the helicopter had descended to approximately 20-30 feet agl. The instructor initiated a flare, and he focused on keeping the skids level, but the right skid hit a dirt ledge adjacent to the proposed landing spot that was approximately 6 feet higher than the surface of the intended landing zone. As the right skid impacted the ground, the helicopter pitched forward, and the nose impacted the ground. The pilot reported no mechanical failures or malfunctions at the time of the accident.

Quoted verbatim from the NTSB record.