# NTSB LAX05TA008: Hughes OH-6A, N6639R, Jacumba, CA, October 15, 2004 - Type: NTSB accident investigation - Classification: Accident · No injuries · Final report - Date: October 15, 2004, 01:15 local (08:15 UTC) - Place: Jacumba, CA - Coordinates: 32.616111, -116.165 - Nearby events: https://openairdocs.org/map.md?lat=32.6161&lon=-116.1650&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report January 31, 2006 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 60363 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX05TA008 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/60363/pdf - Page: https://openairdocs.org/ntsb/LAX05TA008 ## Probable cause the pilot's failure to maintain adequate clearance from the mountainous terrain, which resulted in the helicopter's tail rotor blades impacting rocks. A factor in the accident was the pilot's complacency. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, maneuvering - light condition - dark night - terrain condition - mountainous/hilly - terrain condition - rock(s)/boulder(s) - complacency, pilot in command (contributing factor) - clearance - not maintained, pilot in command (cause) - rotor system,tail rotor blade - blade strike ## Analysis The public-use law enforcement helicopter collided with rocks and terrain while performing low altitude maneuvers in mountainous terrain on a dark night. The pilot maneuvered the helicopter in a turning descent, in an effort to provide the observer with a better view of the area. As he turned the helicopter, he heard a loud bang, followed by a vibration, at which point he opted to land. After egressing the helicopter, he discovered that approximately 3 inches of each tail rotor blade were missing. Days later, while inspecting the accident scene, he also found red and white paint transfers on a rock, located about 100 yards uphill from the landing site; he noted that the tail rotor blades were painted red and white. He thought that his complacency and eagerness to finish the flight might have contributed to him misjudging the maneuver. He reported no mechanical malfunctions of failures with the helicopter prior to impact. ## Factual narrative On October 15, 2004, about 0115 Pacific daylight time, a Hughes OH-6A, N6639R, collided with terrain while performing low altitude maneuvers 4 miles west of the Jacumba Airport, Jacumba, California. The US Border Patrol Air Operations was operating the helicopter under the provisions of 14 CFR Part 91. The commercial pilot and a flight crewmember were not injured; the helicopter sustained substantial damage. The local public-use border patrol flight departed Imperial County Airport, Imperial, California, about 2215 on October 14. Visual meteorological conditions prevailed on the dark night, and a flight plan had not been filed. In a written statement, the pilot reported that he was assisting border patrol ground units with a group of illegal aliens located about 4 miles west of Jacumba, in mountainous terrain consisting of tall weeds and thick brush. While maneuvering in the area, the other flight crewmember, an observer, indicated to the pilot that she thought she saw movement in some bushes located behind the helicopter. The pilot maneuvered the helicopter in a turning descent in an effort to provide the observer with a better view of the area. Thinking that the helicopter's tail rotor would be clear of terrain, the pilot maneuvered around the brush. As he turned the helicopter, he heard a loud bang, followed by a vibration, at which point he opted to land. The pilot further stated that after egressing, he completed an inspection of the helicopter. During the examination he discovered that approximately 3 inches of each tail rotor blade were missing; he did not find any other damage. He reported that 3 days after the accident, while inspecting the accident scene, he found red and white paint transfers on a rock, located about 100 yards uphill from the landing site; he noted that the tail rotor blades were painted red and white. During a telephone conversation with a National Transportation Safety Board investigator, the pilot stated that the accident flight was the last flight of his 6-day workweek. He thought that his complacency and eagerness to finish the flight might have contributed to him misjudging the maneuver. He reported no mechanical malfunctions or failures with the helicopter prior to impact. ## Aircraft - Registration: [N6639R](https://openairdocs.org/deregistered/N6639R-2021-08-07), registration cancelled 2021-08-07, S/N 66-07874 (OpenAirDocs) - Reported make and model: Hughes OH-6A - Registry model: [Hughes OH-6A](https://openairdocs.org/model/hughes-oh-6a) (registry code 4470905) (OpenAirDocs) - Category: Helicopter - Serial number: 66-7874 - Airframe hours: 11304 - Engines: Rolls-Royce 250-C20B 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Public aircraft, Public use - Operator: US Border Patrol - Registered owner: U.S Border Patrol Operations - Last inspection: AAIP, October 12, 2004, 3 hours before - Departed: KIPL, Imperial, CA - Airport: L78, Jacumba Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 37; injuries: none; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane, helicopter; medical: class 1, valid medical--no waivers/lim.; last flight review July 1, 2004; seat: right; flight hours: 2,514 total, 674 in this make and model, 2,095 as pilot in command, 155 in the last 90 days, 72 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night/dark - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 46 °F, dew point 18 °F - Altimeter: 29.95 inHg ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20041015028309A](https://openairdocs.org/incident/20041015028309A), Oct 15, 2004: Hughes OH6A, Jacumba, CA, Minor damage. (-23) On October 15, 2004, about 0115 PDT, a Hughes operated by us border patrol collided with the terrain while performing low altitude maneuvers. According… ## Other investigations on N6639R (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB WPR21LA107](https://openairdocs.org/ntsb/WPR21LA107), Feb 5, 2021: Hughes OH-6A (N6639R), Horseshoe Bend, ID, substantial damage. Probable cause: A partial loss of engine power due to a leak in the fuel cell outlet valve. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.