Incident Overview
On November 5, 2011, at approximately 1620 eastern standard time, a Robinson R22 BETA helicopter, registration N413RM, operated by Ocean Helicopters Inc., was substantially damaged during an autorotation following a loss of rotor rpm. The accident occurred near West Palm Beach, Florida. The certificated private pilot and one passenger sustained minor injuries. The flight was conducted under 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed. The helicopter had departed North Palm Beach Country Airport (F45) at about 1530.
Pilot and Flight Details
The pilot reported that the wind was from the north-northeast at 10 knots, gusting to 20 knots. He was circling a boatyard at an altitude of about 600 feet above ground level at an airspeed of 60 knots while the passenger took photographs. After completing several circuits, as the helicopter turned southbound with carburetor heat engaged, the pilot noticed a loss of airspeed. He moved the cyclic forward to maintain airspeed, but the low rotor rpm horn sounded and the accompanying cockpit indication illuminated. The pilot immediately entered an autorotation, turning left 180 degrees to fly upwind and radioing an emergency to air traffic control. During the autorotation, the helicopter impacted powerlines, trees, and a residence.
Damage and Engine Examination
The helicopter sustained substantial damage to the main rotor blades and fuselage. Following the accident, the engine was test-run on the accident helicopter. It started without hesitation and ran continuously at various power settings, including idle and 100 percent rpm. No anomalies were noted with the engine or its associated controls.
Pilot Experience
The pilot obtained his private pilot certificate on July 26, 2011, with a rating for rotorcraft-helicopter. At the time of the accident, he reported a total flight experience of 67 hours, of which 42 hours were in the same make and model as the accident helicopter. He had flown 8 hours in the preceding 90 days and 1 hour in the preceding 30 days.
Weather and Radar Data
The recorded wind at Palm Beach International Airport (PBI), located about 4 miles southwest of the accident site, was from 020 degrees at 16 knots, gusting to 24 knots at 1553. Radar data obtained from the Federal Aviation Administration indicated that the helicopter made a left 180-degree turn from north to south between 1619:35 and 1620:15. During the turn, the recorded altitude varied between 300 and 400 feet. Nine radar targets were recorded. The first three targets, depicting northward travel, showed an average groundspeed of approximately 27 knots and an average airspeed of about 37 knots based on a 16-knot wind from 020 degrees. The second set of three targets, depicting westward travel in the turn, showed an average groundspeed of about 39 knots and average airspeed of about 47 knots. The third set, depicting travel from west to south at the conclusion of the turn, showed an average groundspeed of 36 knots and average airspeed of 31 knots. Wind gusts were not included in these calculations.
Safety Notice
Robinson Safety Notice SN-34, titled "AERIAL SURVEY AND PHOTO FLIGHTS - VERY HIGH RISK," notes that aerial survey and photo flights are often flown by low-time pilots, leading to numerous fatal accidents. It states that during such flights, inexperienced pilots may slow the helicopter to less than 30 KIAS and lose track of airspeed and wind conditions, risking loss of translational lift and settling. The notice recommends that such flights be conducted only by pilots with at least 500 hours pilot-in-command in helicopters and over 100 hours in the model flown, with extensive training in low rpm and settling-with-power recovery techniques, and willingness to decline unsafe requests.