Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Eagle Pass, Texas 78852
Monday, September 2, 2002 14:40 UTC
NTSB Narrative Summary Released at Completion of Accident
The commercial pilot was in cruise flight with the auto-pilot engaged when the red "GOV" light illuminated and the audio sounded. He disengaged the autopilot and resumed manual control of engine RPM. As the pilot was turning toward his home base, the pilot re-engaged the autopilot, and the engine RPM began to increase and decrease. The pilot was unable to control the RPM and initiated an autorotation to a field. The helicopter landed hard separating the tail boom and fracturing two arms of the main rotor starflex. The helicopter was equipped with a Turbomeca Ariel 2B series engine, which incorporated an electronic engine control unit (EECU) that electronically controlled engine fuel flow via a Hydromechanical Metering Unit (HMU). Data retrieved from the helicopter's flight data computer revealed that the fuel-metering unit valve had malfunctioned. Further investigation revealed that there had been 10 previous incidents worldwide where there was an internal failure in the EECU, which resulted in a red "GOV" warning light illuminating during flight. When this light illuminated, it caused the fuel metering valve to freeze in the position it had at the time of the detection, and therefore engine power could no longer be automatically controlled. The HMU consisted of a resolver and a stepper motor. The resolver measured/sensed the position of the fuel metering valve. The stepper motor took commands from the EECU and physically moved the metering valve. In automatic mode, the HMU compared the resolver information and stepper motor information, as to the position of the fuel -metering valve. When a cumulative mismatch of greater than 7 degrees occurred, the red "GOV" light illuminated and the pilot had to revert to manual mode for throttle operation. Further examination of the Hydromechanical Metering Unit (HMU) revealed that the stepper motor rack was too short and needed to be lengthened.
NTSB Probable Cause Narrative
The insufficient length of the stepper motor rack inside the HMU, which caused the red "GOV" light to illuminate and the fuel metering valve to freeze causing the engine to automatically engage the manual mode.
Event Information
| Type of Event | Accident |
| Event Date | 9/2/2002 |
| Event Day of the Week | Monday |
| Time of Event | 1440 |
| Event Time Zone | Coordinated Universal Time? Same as GMT |
| Event City | Eagle Pass |
| Event State | TEXAS |
| Event Country | -- |
| Zipcode of the event site | 78852 |
| Event Date Year | 2002 |
| Event Date Month | 9 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 283215N |
| Event Location Longitude | 1001935W |
| Event Location Airport | -- |
| 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 | Pilot |
| Time of the weather observation | |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | -- |
| Elevation of weather observation facility | -- |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | -- |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | 5000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 20 |
| Air Temperature at event time (in degrees celsius) | 35 |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | 135 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 10 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Gusting |
| Wind Gust (knots) | 10 |
| Altimeter Setting at event time (in. Hg) | -- |
| 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 | 1 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 22175 |
| NTSB Notification Source | FAA Operations Center |
| NTSB Notification Date | Sep 2 2002 12:00AM |
| NTSB Notification Time | 1558 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Sep 27 2007 11:30AM |
| User who most recently changed record | NTSB\johb |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | San Antonio, Texas |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N747R |
| NTSB Number | FTW02LA247 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Eurocopter |
| Aircraft Model | AS350B3 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 3341 |
| Certified Max Gross Weight | 4961 |
| Aircraft Category | Helicopter |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 6 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Aug 29 2002 12:00AM |
| Airframe hours since last inspection | 5.8 |
| Airframe Hours | 401.5 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Sage Wells |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Encinal |
| Aircraft Owner State | TX |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 78019 |
| Operator is an individual? | No |
| Operator Name | Lewis Energy, Incorporated |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | -- |
| Operator State | -- |
| Operator Country | -- |
| Operator Zip code | -- |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | -- |
| 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) | Business |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | DRT |
| Departure City | Del Rio |
| Departure State | TX |
| Departure Country | USA |
| Departure Time | 1400 |
| Departure Time Zone | TZ |
| Destination Same as Local Flt | -- |
| Destination Airport Code | -- |
| Destination City | Encinal |
| Destination State | TX |
| Destination Country | USA |
| Specific Phase of Flight | Landing - flare/touchdown |
| Report sent to ICAO? | No |
| Evacuation occurred | Yes |
| Date of most recent change to record | Aug 28 2007 3:18PM |
| User who most recently changed record | CASH |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | NA |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |