20110926022899A

Description: on September 26, 2011 at approximately 12:32 local Alaska daylight savings time, N230CH, a Eurocopter AS-350BA astar operated under title 14 CFR part 135 by coastal helicopters, inc., was substantially damaged when it rolled over on its side while at ground idle. Pilot and one passenger were uninjured. The helicopter flight originated from the Juneau airport (pajn) enroute to the 3,200 ft landing/accident site at approximately 25 NM northwest of the Juneau airport near davies creek. The helicopter was a commercial charter flight with the united states forest service (usfs). Two usfs workers were dropped off by N230CH earlier in the day to work on a weather station located on a ridgeline. The accident occurred while preparing to pick up the usfs workers for the return flight to Juneau. The helicopter landed on a ridgeline several hundred feet north of where the usfs personnel were working. The pilot and the usfs helicopter manager noticed that the workers were not ready so they were going to shutdown and wait. The pilot was cooling down the engine (Honeywell LTS-101) for shutdown when the pilot noticed the wind increasing and a small group of trees off his right side that started shaking violently. The pilot was debating not to shut down due to the high winds and possibly to fly the helicopter to an alternate landing area to wait. A large gust of wind developed before the pilot was able to discuss this option with the usfs helicopter manager. The aircraft yawed to the right, the main rotor contacted the ground, and the aircraft rolled onto its left side. The pilot applied left pedal when he noticed the intial yaw to the right. Pilot did not react with any other control inputs. One of the usfs workers reported after the accident: "after we were dropped off at our site we experienced several large wind gusts as we were setting up our equipment."closest FAA weather reporting stations:METAR pajn 262053Z 25013G16KT 10SM FEW130 SCT160 BKN190 11/04 A2927 rmk AO2 SLP911 T01110044 56060METAR pahn 262054Z auto 29014G22KT 10 sm BKN043 11/03 A2940 rmk AO2 SLP959 T01110033 58038 tsnowinds aloft forecast for the Juneau area for September 26, 2011: 3,000 ft: 0610, 6,000 ft: 0913-04, 9000 ft: 0910-09NATIONAL weather service observations from a sea level marine weather station located at eldred rock (23 NM nw of accident site) reported winds on September 26, 2011 at 12:00 LCL adt as north 31 knots peak 38 knots and at 13:00 LCL adt as north 33 knots peak 42 knots. No other wind data is available closer to the accident site. No PIREP data was available for this location during the time period of the N230CH accident. Coastal helicopters, inc. utilizes a flight risk assessment process developed under their medallion foundation safety program. The flight risk assessment process incorporates a checks and balances risk management process that includes the pilot, operational control, and flight coordinators. The go/no go decision process incorporates pilot qualifications and mission factors that include weather, landing area, route familiarity, and other criteria. The flight risk assessment for this accident flight was a "go" for operational control, flight coordinator, and the pilot.a flight risk assessment basic pilot qualification criteria matrix is utilized at coastal helicopters, inc. to determine pilot limitations of ceiling visibility, wind, minimum altitude, maximum landing elevations, and landing area restrictions. This flight risk assessment process was used for this accident flight. Possible contributing factors: strong, gusty winds, lack of wind forecast or wind data for accident landing area. Recommended corrective action: operator will re-evaluate voluntary risk management process and redesign if required. Operator will re-evaluate safety program controls and wind and landing zone selection in their training program.