Incident Overview
On September 24, 2010, at 1634 eastern daylight time, an American Eurocopter AS-350B2, registration N91DK, operated by the Dekalb County Police, was substantially damaged following a loss of control during landing at Covington Airport (9A1) in Covington, Georgia. The certificated commercial pilot and the certificated flight instructor sustained minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed for the local public use instructional flight.
Sequence of Events
The flight instructor reported to witnesses, police, and a Federal Aviation Administration (FAA) inspector that he and the pilot had been performing hydraulics-off maneuvers, the helicopter "got away from them," and control could not be regained prior to ground contact.
According to the pilot, he was conducting recurrent training with the instructor, a contractor not affiliated with the Dekalb County Police. They had returned from a meal break, and this was the second flight of the day. The instructor simulated a hydraulics failure by "turning off" the flight control hydraulics switch, and the pilot was to perform a hydraulics-off, run-on landing as the remedial action. As the helicopter slowed over the runway, the nose yawed to the left, and the pilot was unable to correct with right pedal input. The instructor announced and took control, completing a low-level, left-hand orbit to demonstrate and complete the maneuver.
As the helicopter completed the left orbit and lined up for landing, it "rolled wings level" but then continued to roll to the right and collided with terrain. The pilot stated that the entire maneuver was conducted hydraulics-off, and he felt the instructor had control until the roll past wings-level to the right. The instructor had successfully completed a similar maneuver earlier in the day without restoring the flight control hydraulics.
Personnel Information
The pilot held a commercial pilot certificate with a rating for rotorcraft helicopter. His most recent FAA second class medical certificate was issued July 14, 2010. He reported 929 total hours of flight experience, all in the accident helicopter make and model.
The flight instructor held a commercial pilot certificate with ratings for airplane single engine, multiengine, rotorcraft-helicopter, and instrument airplane and helicopter. He also held a flight instructor certificate for airplane single engine, rotorcraft-helicopter, and instrument airplane and helicopter. His most recent FAA second class medical certificate was issued April 12, 2010, and he reported 4,100 total hours of flight experience on that date.
Aircraft Information
According to the operator, the helicopter had accrued 3,158 total aircraft hours. Its most recent 100-hour inspection was completed on August 12, 2010, at 3,100 total aircraft hours.
Weather Conditions
At 1650, weather reported at Lawrenceville Airport (LZU), 21 miles north of the site, included scattered clouds at 5,500 feet, winds from 200 degrees at 5 knots, visibility 10 miles, temperature 32 degrees Celsius, dew point 21 degrees Celsius, and an altimeter setting of 30.09 inches of mercury.
Damage and Examination
Examination by an FAA inspector revealed substantial damage to the cockpit, cabin structure, and landing gear. Both the pilot and the instructor stated that there was nothing wrong with the performance and handling of the helicopter.
Flight Manual Guidance
The Eurocopter AS 350 B2 Flight Manual (Emergency Procedures) and Flight Manual Supplement for Hydraulic Pressure Failure Training Procedures include a caution: "DO NOT ATTEMPT TO CARRY OUT HOVER FLIGHT OR ANY LOW SPEED MANEUVER WITHOUT HYDRAULIC PRESSURES ASSISTANCE. THE INTENSITY AND DIRECTION OF THE CONTROL FEEDBACK FORCES WILL CHANGE RAPIDLY. THIS WILL RESULT IN EXCESSIVE PILOT WORKLOAD, POOR AIRCRAFT CONTROL, AND POSSIBLE LOSS OF CONTROL."