Individually Owned: 151,845
Corporate Owned: 143,699
Aircraft Accident/Incident Report
Grants, New Mexico 87020
Thursday, May 10, 2012 10:15 MDT
NTSB Narrative Summary Released at Completion of Accident
The helicopter, which had been based at sea level, had recently been sold, and the flight instructor and a commercial pilot were flying it across the country to its new base. While in cruise flight over mountainous terrain at high density altitude, the flight instructor initiated a practice autorotation for the purpose of maintaining proficiency. During the autorotation, the engine stopped producing power. The instructor continued the autorotation to a landing; however, during the landing, the main rotor blades severed the tail boom. A postaccident engine run at high density altitude revealed that the engine ran rough at an idle power setting with a full rich fuel mixture. Leaning the fuel mixture improved engine performance. It is likely that the fuel control unit was set by maintenance personnel to provide a rich mixture at sea level, which resulted in poor engine performance at high density altitudes.
NTSB Probable Cause Narrative
The loss of engine power due to an excessively rich fuel mixture that occurred during operations at idle power settings at a high density altitude. Contributing to the accident was the flight instructor’s poor decision-making in choosing to practice an unnecessary autorotation over mountainous terrain.
Event Information
| Type of Event | Accident |
| Event Date | 5/10/2012 |
| Event Day of the Week | Thursday |
| Time of Event | 1015 |
| Event Time Zone | Mountain Daylight Time |
| Event City | Grants |
| Event State | NEW MEXICO |
| Event Country | -- |
| Zipcode of the event site | 87020 |
| Event Date Year | 2012 |
| Event Date Month | 5 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | -- |
| Event Location Longitude | -- |
| Event Location Airport | -- |
| Event Location Nearest Airport ID | -- |
| Indicates whether the acc/inc occurred off or on an airport | -- |
| 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 | 953 Mountain Daylight Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | KGNT |
| Elevation of weather observation facility | 6537 |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | MDT |
| 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) | -- |
| Air Temperature at event time (in degrees celsius) | 17 |
| Dew Point at event time (in degress fahrenheit) | -4 |
| Wind Direction (degrees magnetic) | 170 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 5 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.06 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | METAR KGNT 111553Z AUTO 17005KT 17/M04 A3006 RMK A |
| 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) | 31057 |
| NTSB Notification Source | -- |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Jan 15 2013 12:50PM |
| User who most recently changed record | aguj |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N7523S |
| NTSB Number | CEN12LA289 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | VFR |
| Flight plan Was Activated? | Yes |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | ROBINSON HELICOPTER COMPANY |
| Aircraft Model | R44 II |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 10276 |
| Certified Max Gross Weight | 2400 |
| 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 | Apr 29 2012 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | 1377.3 |
| ELT Installed | Yes |
| ELT Activated | Yes |
| ELT Aided Location of Event Site | No |
| ELT Type | C91-A |
| Aircraft Owner Name | ROTORTRENDS INC |
| Aircraft Owner Street Address | 40 E MAIN ST # 1320 |
| Aircraft Owner City | NEWARK |
| Aircraft Owner State | DE |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 19711-4639 |
| Operator is an individual? | No |
| Operator Name | iPrerogative, Inc |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | Washington |
| Operator State | UT |
| Operator Country | USA |
| Operator Zip code | -- |
| 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) | Ferry |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | KABQ |
| Departure City | Albuquerque |
| Departure State | NM |
| Departure Country | USA |
| Departure Time | 900 |
| Departure Time Zone | MDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | KPGA |
| Destination City | Page |
| Destination State | AZ |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Oct 1 2012 4:24PM |
| User who most recently changed record | aguj |
| Since inspection or accident | Last Inspection |
| Event Location Runway Number and Location | -- |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | -- |
| Air Medical Flight | -- |
| Medical Flight | -- |