# NTSB LAX06CA296: Bell 47G, N7762, Angels Camp, CA, September 18, 2006 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: September 18, 2006, 08:00 local (15:00 UTC) - Place: Angels Camp, CA - Coordinates: 38.016666, -120.466667 - Nearby events: https://openairdocs.org/map.md?lat=38.0167&lon=-120.4667&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report January 31, 2007 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 64577 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX06CA296 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/64577/pdf - Page: https://openairdocs.org/ntsb/LAX06CA296 ## Probable cause a hard landing due to the pilot's inadequate compensation for a wind shift encountered on final approach and his failure to maintain an adequate translational lift airspeed. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, landing - compensation for wind conditions - inadequate, pilot in command (cause) - weather condition - sudden windshift (contributing factor) - translational lift - not maintained, pilot in command (cause) - terrain condition - berm - proper glidepath - not maintained, pilot in command (cause) ## Analysis During an approach to land on a flat clear-cut plateau near a local vineyard, the wind shifted and the helicopter landed hard coming to rest on its left side. The pilot noted various obstacles at the approach end of the landing zone; two trees about 50 feet apart from each other, which he intended to fly between, a 6-foot-high mound, followed by a 2-foot hole, and another 2-foot mound, and then a flat area with no additional obstacles. On the approach, the wind shifted from a headwind to a tail wind. The pilot reported that the airspeed dropped below ETL (effective translational lift) and resulted in a loss of lift. He pushed the cyclic forward to gain forward airspeed and applied cyclic and power to avoid contacting the terrain below the top of the plateau. This maneuver assisted in gaining altitude, placing the helicopter above the plateau, but not above the 6-foot mound. He flared the helicopter, and as it passed over the mound, the tail rotor guard struck the top of the mound, which placed the helicopter in a nose down attitude. One of the landing gear skids collided with the 2-foot mound, which broke off the tailboom. At that point, the helicopter yawed to the right and started to roll to the left, and came to rest about 5 feet from the mound, lying on its left side. ## Factual narrative On September 18, 2006, about 0800 Pacific daylight time, a Bell 47G, N7762, landed hard on uneven terrain and rolled over near Angels Camp, California. Arrow Aviation, d.b.a. Gunner Aviation, operated the helicopter under the provisions of 14 CFR Part 91 as an aerial observation flight. The helicopter sustained substantial damage. The commercial helicopter pilot and one passenger were not injured. Visual meteorological conditions prevailed for the flight that departed Rancho Murieta, California, about 0615. The helicopter came to rest at global positioning system (GPS) coordinates of 38 degrees 1 minute north latitude and 120 degrees 28 minutes west longitude. In the pilot's written statement to the National Transportation Safety Board, he indicated that they had been flying for about 2 hours, just east of Angels Camp, and planning on returning to RIU. He reported that both he and his passenger need to use a restroom. He knew it would be 20 minutes to Calaveras Airport, or 50 minutes to RIU, and decided to land so that he would be better able to focus on the return flight to RIU. The pilot chose to land on a flat clear-cut plateau near a local vineyard. The plateau was 100 feet by 200 feet. The area that he determined would be used for the approach had two trees that were at least 50 feet apart, which would give him sufficient clearance to fly between them. He also noted that at the approach end was a 6-foot-high mound, followed by a 2-foot hole, and another 2-foot mound; all were about 10 feet in diameter, with the remainder of the area as flat with no additional obstacles. The pilot reported that he began a steep approach into the wind. The helicopter was about 50 feet from the end of the plateau when the wind shifted, which created a tail wind condition. The airspeed dropped below ETL (effective translational lift) that resulted in a loss of lift. The loss of lift altered the angle of the approach from a flat landing area to an approach that was on the downslope of the plateau. The pilot pushed the cyclic forward to gain forward airspeed, and applied collective and power to avoid contacting the slope of the plateau. After performing this maneuver, the helicopter was above the level of the plateau; however, it did not put the helicopter above the 6-foot mound. He flared the helicopter to gain additional altitude then leveled the helicopter as it approached the mound. As the helicopter passed over the mound, the tail rotor guard struck the top of the mound, which forced the nose of the helicopter in a downward attitude. The landing gear skid collided with the 2-foot mound and the tailboom broke off. The helicopter began to yaw to the right and roll to the left. The helicopter cleared the 2-foot mound, and came to rest about 5 feet from the mound, lying on its side. ## Aircraft - Registration: [N7762](https://openairdocs.org/aircraft/N7762), registered now, S/N K931, built 1969 (OpenAirDocs) - Reported make and model: Bell 47G - Registry model: [Bell-K-Copter 47G](https://openairdocs.org/model/bell-k-copter-47g) (registry code 1181065) (OpenAirDocs) - Registry engine: [Franklin 6A4200 series](https://openairdocs.org/engine/franklin-6a4200-series) (registry code 27027, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: K-931 - Engines: Franklin VO-335 reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Arrow Aviation, doing business as Gunner Aviation - Registered owner: Children's Aviation Fund - Airworthiness certificate: Standard, Normal - Departed: RIU, Rancho Murieta, CA - Destination: RIU ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 27; injuries: none; commercial; medical: class 2; flight hours: 600 total, 500 in this make and model, 100 in the last 90 days, 25 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20060918018859A](https://openairdocs.org/incident/20060918018859A), Sep 18, 2006: Bell 47G, Vallecito, CA, Substantial damage. (-23) Pilot states that he was on a title 14 CFR part 91 photo flight. After the photographer had taken his pictures the pilot states that he asked his… ## Other investigations on N7762 (2) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB CHI79DEM02](https://openairdocs.org/ntsb/CHI79DEM02), Oct 1, 1978: Bell 47G (N7762), Saginaw, MI, substantial damage - [NTSB FTW75FPD33](https://openairdocs.org/ntsb/FTW75FPD33), Apr 8, 1975: Bell 47K (N7762), Arlington, TX, substantial damage From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.