None Airport
Aircraft Accident/Incident Report

Valentine, Texas 79584
Friday, February 8, 2008 11:15 CST

NTSB Narrative Summary Released at Completion of Accident

The commercial pilot/air interdiction agent was engaged in a United States Custom and Border Patrol (CBP) mission in a single-engine turbine equipped helicopter when the engine stopped producing power and the helicopter descended rapidly from a height of 30-50 feet above the ground. The pilot maintained directional control and made a hard landing in a wash-out. The helicopter remained upright, but the skids were completely spread, the tail rotor blades were damaged, and the fuselage sustained structural damage. Further examination of the engine revealed that a castellated nut used to secure the governor lever control rod to the idler bell crank had come completely loose, and the cotter pin that secured the nut was missing. The engine had been replaced 5.1 hours prior to the accident by a contract maintenance facility. The mechanic stated that during the first engine run-up, he discovered an oil leak on the left side of the engine. As a result, the engine was shut down and the linkages on the left side of the engine were disassembled, including the governor level control rod assembly. During the reassembly, he got distracted by a phone call, which delayed him from completing the repair. As a result, when he returned to complete the repair, he got "tunnel vision" and forgot to install the cotter pin during the reassembly process, which would have kept the castellated nut that secured the attachment bolt for the governor level control rod from loosening. According to CBP, their agency was responsible for the oversight of this maintenance and the helicopter was returned to service in accordance with the military technical manuals. However, there were no established inspection procedures to properly accept an aircraft that had just undergone a major repair. In addition, a review of the OH-6A Technical Manuals revealed that only a standard castellated nut and cotter pin was needed to properly install the governor lever control rod, while the more recent Hughes 500 repair manual and an FAA Airworthiness Directive required a castellated nut with fiber inserts to prevent the nut from backing off.

NTSB Probable Cause Narrative

The contract mechanic's failure to properly secure the castellated nut that attached the governor lever control rod to the idler bell crank. Contributing to the accident was the lack of maintenance oversight by the operator.

Event Information

Type of Event Accident
Event Date 2/8/2008
Event Day of the Week Friday
Time of Event 1115
Event Time Zone Central Standard Time
Event City Valentine
Event State TEXAS
Event Country --
Zipcode of the event site 79584
Event Date Year 2008
Event Date Month 2
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 303509N
Event Location Longitude 1042926W
Event Location Airport None
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 1115 Central Standard Time
Direction of event from weather observation facility (degrees) 160
Weather Observation Facility ID MRF
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) 40
Time Zone of the weather observation CST
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) 12
Dew Point at event time (in degress fahrenheit) 9
Wind Direction (degrees magnetic) 0
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) --
Wind Velocity Indicator Calm
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 30.23
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Minor
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor 1
Injury Total None --
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 24319
NTSB Notification Source US Customs/Border Protection A
NTSB Notification Date Feb 9 2008 12:00AM
NTSB Notification Time --
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Sep 26 2008 6:40PM
User who most recently changed record NTSB\lema
Basic weather conditions Visual Meteorological Cond
FAA District Office Lubbock, TX

Aircraft Involved

Aircraft #1

Aircraft Registration Number N66372
NTSB Number DFW08TA066
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 Hughes
Aircraft Model OH-6
Aircraft Series Identifier --
Aircraft Serial Number 67-16595
Certified Max Gross Weight 2700
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 Continuous Airworthiness
Date of Last Inspection Jan 1 2008 12:00AM
Airframe hours since last inspection --
Airframe Hours 5999
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name Customs and Border Protection
Aircraft Owner Street Address --
Aircraft Owner City --
Aircraft Owner State --
Aircraft Owner Country --
Aircraft Owner Zipcode --
Operator is an individual? No
Operator Name --
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address --
Operator City El Paso
Operator State TX
Operator Country USA
Operator Zip code 79906
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) --
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code MRF
Departure City Marfa
Departure State TX
Departure Country USA
Departure Time 940
Departure Time Zone CST
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code --
Destination City --
Destination State --
Destination Country --
Specific Phase of Flight Maneuvering
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Sep 12 2008 3:48PM
User who most recently changed record GAMW
Since inspection or accident Last Inspection
Event Location Runway Number and Location NA
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --