Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Broadus, Texas 75940
Thursday, March 27, 2003 16:36 CST
NTSB Narrative Summary Released at Completion of Accident
While establishing a 125-foot out of ground effect hover during a search and recovery mission of Columbia Space Shuttle debris, the helicopter lost power without warning, descended rapidly into a forest with 80-foot tall trees, and impacted the ground. There were no reported radio communications or distress calls. During post accident component examinations, while performing the rigging procedure for the Hydro-Mechanical Unit (HMU) during an engine test cell run, anomalies were noted with the actual position of the throttle Position Lever Angle (PLA) and the readings obtained from the Electronic Control Unit (ECU). During the test cell run, the Full Authority Digital Electronic Control System (FADEC) controlled engine operated erratically in the Auto mode when rigged with its original Electronic Control Unit (ECU) and (HMU). The engine control was then changed from Auto to Manual mode, and the engine responded to throttle input as required; however, the ECU readings were erratic. After a slave ECU was installed, the engine operated with similar erratic readings. A slave HMU was installed, and the engine operated normally without erratic readings. The ECU's nonvolatile memory was downloaded, and revealed no faults on the accident flight. Extensive electrical and mechanical testing of the HMU revealed severe signal fallout on the PLA signal, which was found to be random in location, bi-directional, and present during both rotational and stationary operation of the PLA input of the HMU. The source of the fallout was traced to the HMU potentiometer. The PLA potentiometer examinations consisted of mechanical measurements, electrical testing, inspection of the conductive epoxy joints, and microscopic examination of the three lead wire connections to the potentiometer elements. The PLA potentiometer was found faulty due to insulation breakdown between the rotor and shaft, resulting in a single-point failure that induced erratic fuel metering to the engine. As a result of the findings from this investigation, the Safety Board issued four safety recommendations (A-03-18 through A-03-21), on May 27, 2003, to the FAA that addressed the PLA potentiometer deficiencies.
NTSB Probable Cause Narrative
The partial loss of engine power due to erratic fuel flow metering to the engine resulting from the single point failure of the PLA potentiometer in the hydro-mechanical fuel control unit. A contributing factor was the lack of suitable terrain to execute a forced landing.
Event Information
| Type of Event | Accident |
| Event Date | 3/27/2003 |
| Event Day of the Week | Thursday |
| Time of Event | 1636 |
| Event Time Zone | Central Standard Time |
| Event City | Broadus |
| Event State | TEXAS |
| Event Country | -- |
| Zipcode of the event site | 75940 |
| Event Date Year | 2003 |
| Event Date Month | 3 |
| MidAir Collision Indicator | -- |
| On Ground Collision occurred ? | -- |
| Event Location Latitude | 311823N |
| Event Location Longitude | 0940705W |
| 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 | -- |
| 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) | 12 |
| Wind Direction (degrees magnetic) | 190 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 12 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Gusting |
| Wind Gust (knots) | 19 |
| Altimeter Setting at event time (in. Hg) | 29.66 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | Fatal |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | 2 |
| Injury Total Minor | -- |
| Injury Total None | -- |
| Injury Total Serious | 3 |
| Injury Total All | 5 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 20918 |
| NTSB Notification Source | FAA Operations Center |
| NTSB Notification Date | Apr 27 2003 12:00AM |
| NTSB Notification Time | 1830 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Nov 29 2006 12:45PM |
| User who most recently changed record | NTSB\johb |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Houston, Texas |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N175PA |
| NTSB Number | FTW03FA118 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | Company VFR |
| Flight plan Was Activated? | Yes |
| Damage | Destroyed |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Bell |
| Aircraft Model | 407 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 53154 |
| Certified Max Gross Weight | 4600 |
| 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 | 7 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Mar 1 2003 12:00AM |
| Airframe hours since last inspection | 3.4 |
| Airframe Hours | 3339.5 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | I Inc. |
| Aircraft Owner Street Address | 1215 Willow Road NE #200 |
| Aircraft Owner City | Kirkland |
| Aircraft Owner State | WA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 98034 |
| Operator is an individual? | No |
| Operator Name | FEMA, USFS, TFS |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | Columbia Debris Recovery Disaster Field Office |
| Operator City | Lufkin |
| Operator State | TX |
| Operator Country | USA |
| 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) | Public Use |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | LFK |
| Departure City | Lufkin |
| Departure State | TX |
| Departure Country | USA |
| Departure Time | 1515 |
| Departure Time Zone | CST |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | LFK |
| Destination City | -- |
| Destination State | -- |
| Destination Country | -- |
| Specific Phase of Flight | Hover - out of ground effect |
| Report sent to ICAO? | Yes |
| Evacuation occurred | No |
| Date of most recent change to record | Nov 24 2006 4:12PM |
| User who most recently changed record | CASH |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | NA |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |