Individually Owned: 150,657
Corporate Owned: 137,281
N/A Airport
Aircraft Accident/Incident Report
Mammoth Lakes, California 93546
Wednesday, September 19, 2012 12:25 PDT
NTSB Narrative Summary Released at Completion of Accident
While performing an aerial survey of transmission structures and wires in mountainous terrain at an elevation of about 7,500 feet mean sea level, the pilot initiated a climb to clear a ridge ahead. When he realized that there was no response to an increase in collective, and, with the torque nearing 100 percent, he chose to maneuver the helicopter left of a set of wires, avoid approaching terrain, and establish an approach for a precautionary landing to a dirt road. The pilot reported that, during the approach, he was unable to arrest the helicopter’s descent, and, at the same time, he heard a noise that he assumed was the low rotor rpm warning. The helicopter subsequently impacted terrain just short of the road, rolled over on its left side, and was consumed by the postcrash fire. A postaccident examination of the airframe and engine revealed no mechanical anomalies that would have precluded normal operation. At the time of the accident, the nearest weather reporting facility, which was located 10.5 miles west of the accident site, reported wind at 4 knots, gusting to 14 knots, and a temperature of 24 degrees C. The calculated density altitude for the conditions was about 9,742 feet, which would have affected the helicopter’s climb performance.
NTSB Probable Cause Narrative
The pilot’s inability to maintain sufficient main rotor rpm while maneuvering in high density altitude conditions, which resulted in a precautionary landing and subsequent rollover.
Event Information
| Type of Event | Accident |
| Event Date | 9/19/2012 |
| Event Day of the Week | Wednesday |
| Time of Event | 1225 |
| Event Time Zone | Pacific Daylight Time |
| Event City | Mammoth Lakes |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 93546 |
| Event Date Year | 2012 |
| Event Date Month | 9 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 374008N |
| Event Location Longitude | 1183707W |
| Event Location Airport | N/A |
| Event Location Nearest Airport ID | -- |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1235 Pacific Daylight Time |
| Direction of event from weather observation facility (degrees) | 260 |
| Weather Observation Facility ID | MMH |
| Elevation of weather observation facility | 7135 |
| Distance of event from weather observation facility (units?) | 14 |
| Time Zone of the weather observation | PDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | Clear |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 24 |
| Dew Point at event time (in degress fahrenheit) | -5 |
| Wind Direction (degrees magnetic) | 120 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 4 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Gusting |
| Wind Gust (knots) | 14 |
| Altimeter Setting at event time (in. Hg) | 30.38 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 2 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 32636 |
| NTSB Notification Source | Regional Operations Center |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Dec 21 2013 6:04AM |
| User who most recently changed record | litt |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N222GR |
| NTSB Number | WPR12LA426 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Destroyed |
| Aircraft Fire | Ground |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | BELL |
| Aircraft Model | 206 - B |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 1638 |
| Certified Max Gross Weight | 3350 |
| Aircraft Category | Helicopter |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 4 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Sep 13 2012 12:00AM |
| Airframe hours since last inspection | 17 |
| Airframe Hours | 21667 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | Unknown |
| Aircraft Owner Name | Aerial Resources LLC |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Chesapeake |
| Aircraft Owner State | VA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 23321 |
| Operator is an individual? | No |
| Operator Name | Chesapeake Bay Helicopters |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | Chesapeake |
| Operator State | VA |
| Operator Country | USA |
| Operator Zip code | 23321 |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | -- |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | -- |
| Indicates Domestic or International Flight | -- |
| Operator carrying Pax/Cargo/Mail | -- |
| Type of Flying (Per_Bus / Primary) | Aerial Observation |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | MMH |
| Departure City | Mammoth |
| Departure State | CA |
| Departure Country | USA |
| Departure Time | 1205 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | MMH |
| Destination City | Mammoth |
| Destination State | CA |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Mar 21 2014 5:58PM |
| User who most recently changed record | stam |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |