Aviation Accident Summaries

Aviation Accident Summary LAX03CA220

Chandler, AZ, USA

Aircraft #1

N7508E

Robinson R22 Beta

Analysis

The helicopter made a hard landing during a practice autorotation and rolled over. The certified flight instructor (CFI) initiated a "throttle chop." The student turned the helicopter into the wind and the airspeed decreased. He lowered the nose in an attempt to gain airspeed; however, the rotor rpm began to decay. The CFI stated "I've got it," but the student did not release the controls. The CFI attempted a recovery maneuver but was unable to recover the lost rotor rpm. About 30 feet above ground level (agl), the student relinquished the controls. Just prior to impact, the helicopter shuddered. It impacted on the forward portion of the skids, the main rotor struck the tail boom, and came to rest on its right side. The student did not relinquish control until the CFI stated for a third time, "I've got it." No mechanical malfunctions were noted with the helicopter.

Factual Information

On June 30, 2003, at 1802 mountain standard time, a Robinson R22 Beta, N7508E, made a hard landing during a practice autorotation near Chandler, Arizona. Quantum Helicopters, Inc., was operating the helicopter under the provisions of 14 CFR Part 91. The certified flight instructor (CFI) and student were not injured; the helicopter sustained substantial damage. The flight departed Chandler Municipal Airport (CHD), Chandler, about 1715, for the local instructional flight. Visual meteorological conditions prevailed and no flight plan had been filed. The CFI reported that he initiated an announced "throttle chop" about 600 feet above ground level (agl) to the student who was training for his flight instructor certificate. Five seconds after lowering the collective, the student turned into the wind. While in the turn the student applied aft cyclic. The CFI brought this to the student's attention; the student applied forward cyclic. The rotor rpm began to decay. The CFI stated "I've got it," and attempted to slow the helicopter from about 75 knots indicated airspeed (KIAS) and recover the rpm. He felt the student on the controls. The CFI stated again, "I've got it" and noticed that the rpm was "dangerously low" at an altitude about 60 feet agl. The CFI attempted a low rotor rpm recovery maneuver but was unable to recover the lost rpm. About 30 feet agl prior to impact, the CFI noted the student's hands in the air, relinquishing the controls. As the helicopter descended, the CFI attempted to keep it level and applied aft cyclic. About 3 seconds prior to impact, he felt a shudder from the helicopter. The helicopter hit on the forward portion of the skids and the main rotor struck the tail boom. The right skid dug into the ground and the helicopter rolled over and came to rest on its right side. The student reported the CFI initiated the second "throttle chop" of the flight. The student lowered the collective and entered an autorotation. During a turn into the wind, the airspeed became excessively low so he "nosed over." Then he was told to watch his rpm. He rolled out of the turn and the low rotor rpm horn sounded. The CFI said, "I have control." The student reported that after the CFI stated that three times, he relinquished control. No mechanical malfunctions were noted with the helicopter.

Probable Cause and Findings

The student's failure to maintain adequate main rotor rpm and his failure to relinquish the controls.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports