NTSB Factual Report

On October 18, 2007, at 0915 central daylight time, a single-engine Robinson R-22 helicopter, N92HS, sustained substantial damage during a forced landing to a sugar cane field near the Acadiana Regional Airport (ARA), near New Iberia, Louisiana. The certificated flight instructor and the private pilot receiving instruction were not injured. The helicopter was registered to and operated by Vortex Helicopters, Incorporated, of New Iberia, Louisiana. Visual meteorological conditions prevailed and no flight plan was filed for the local instructional flight conducted under 14 Code of Federal Regulations Part 91.

In a written statement, the flight instructor reported that he and his student were executing a left hand turn at an altitude of 300 feet above the ground, when the nose of the helicopter made an uncommanded yaw to the left. He added that the low-rotor RPM horn sounded and he immediately lowered the collective, "rolled on the throttle," and applied right anti-torque pedal to counteract the left yaw. When the helicopter was approximately 40-feet above the ground, the instructor initiated an autorotational flare. He added that "the skids impacted the ground in a sugar cane field perpendicular to the rows causing the nose to pitch forward. The front skids dug into a row and caused the helicopter to roll."

According to the private pilot, the flight departed from Runway 16 and made a normal climb to an altitude of 300-feet before making a left hand turn. He said that "almost immediately, the nose of the helicopter started a more aggressive turn to the left and I remember the low RPM warning light and horn coming on." The instructor immediately told the pilot to lower the collective and roll throttle. When the helicopter was approximately 20-30 feet above the ground, the instructor initiated a landing flare. The helicopter's left skid impacted the ground and the helicopter rolled over on its side. The pilot said the entire event seemed to happen in about 2 to 4 seconds from the time the low rotor RPM horn sounded to the time the helicopter rolled over on its side.

A witness, who was another helicopter flight instructor giving instruction at the same time, heard a radio transmission over the airport's tower frequency from the accident helicopter. The witness said he was unable to understand the transmission, but heard the sound of a low rotor RPM horn in the background. Shortly after, he heard the flight instructor make another radio transmission announcing that they had gone down near the departure end of the airport. During the second transmission, the witness could still hear the sound of the low rotor RPM horn in the background.

A Federal Aviation Administration (FAA) inspector performed an on-scene examination of the helicopter. According to the inspector, the helicopter came to rest about a half-mile south of the airport, just off airport property in a sugar cane field. He reported that the front of the helicopter's skids appeared to have caught in the deep furrows of the field, which caused the helicopter to roll on to its left side. The tail boom and left skid had separated from the airframe. The fuel tank was found to be approximately 1/4-full. The helicopter was recovered to a secure facility and an examination of the airframe, the engine, and the fuel system did not reveal any pre-mishap discrepancies.

The FAA inspector also interviewed both pilots, and said that their accounts of the accident were consistent with each other and with the damage observed at the accident site.

The flight instructor held a commercial pilot certificate for rotorcraft-helicopter, instrument helicopter, and a flight instructor rating for rotorcraft-helicopter. His last second class FAA medical was issued in July 2007. He reported having accumulated a total of 661 hours, of which 208 hours were in the last 90 days.

The pilot held a private pilot certificate for rotorcraft-helicopter, and instrument helicopter. His last second class FAA medical was issued in January 2007. He reported having accumulated a total of 155 hours.

Weather at the airport, at 0947, was reported as wind from 210 degrees at 10 knots, visibility 10 statute miles, few clouds 1,500 feet, temperature 82 degrees Fahrenheit, dewpoint 78 degrees Fahrenheit, and a barometric pressure setting of 29.74 inches of Mercury.

NTSB Probable Cause

The private pilot's failure to maintain main rotor rpm, which resulted in a hard landing and subsequent rollover. Also causal was the flight instructor's delayed remedial action. A factor was the lack of suitable terrain the forced landing.