# NTSB FTW03TA156: Bell 407, N991SP, Franklin, LA, May 19, 2003 - Type: NTSB accident investigation - Classification: Accident · No injuries · Final report - Date: May 19, 2003, 09:55 local (14:55 UTC) - Place: Franklin, LA - Coordinates: 30.533056, -91.149444 - Nearby events: https://openairdocs.org/map.md?lat=30.5331&lon=-91.1494&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report March 2, 2004 - Report: Approved by Office Director - Parties: FAA FSDO - NTSB case key (mKey): 57020 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW03TA156 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/57020/pdf - Page: https://openairdocs.org/ntsb/FTW03TA156 ## Probable cause The loss of tail rotor effectiveness due to the inadequate maintenance performed by other company personnel. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Rotor failure/malfunction, approach - rotorcraft flight control,tail rotor control - loss,total - maintenance,installation - inadequate, other maintenance personnel (cause) - rotorcraft flight control,pitch change rod/link - loose part/bolt/nut/clamp/etc - Loss of control - in flight, approach - loss of tail rotor effectiveness - In flight collision with terrain/water, emergency descent/landing - terrain condition - ground ## Analysis When approaching a helipad for landing, the pilot realized that the anti-torque pedals were not effective. Due to obstacles, the pilot aborted his approach to the helipad and turned eastbound toward a sugar cane field. Subsequently, the helicopter started to rotate and the pilot realized he had no control of the tail rotor with the anti torque pedals. He then rolled the throttle to idle, and initiated an autorotation from approximately 75 feet AGL. The pilot reported that a high sink rate developed and the helicopter impacted the ground hard on the main landing skids. Inspection of the helicopter revealed that the pivot bolt (P/N: NAS6604D31), bushing (P/N: 206-011-726-005), nut (P/N: MS14144l4), and cotter pin (P/N: MS24665-155), that connects the rotor control idler assembly (P/N: 406-012-127-101) to the tail rotor control housing assembly was not found. Examination of the aircraft logbooks indicated that there was an annual maintenance inspection preformed on the helicopter 7 days hours prior to the accident. The helicopter accumulated 4.9 hours of flight time since time of inspection. ## Factual narrative On May 19, 2003, at 0955 central daylight time, a Bell 407 helicopter, N991SP, registered to and operated by the Louisiana Department of Public Safety, was substantially damaged during a precautionary following a loss of tail rotor pitch control near Franklin, Louisiana. The commercial pilot and his passenger were not injured. Visual meteorological conditions prevailed and a Company VFR flight following plan was filed for the 14 Code of Federal Regulations Part 91 Public Use flight. The local flight originated from Baton Rouge Airport (BTR), Baton Rouge, Louisiana, at 0900, and was destined for Franklin, Louisiana. The pilot reported in the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) that while he was approaching a helipad for landing, he realized that the anti-torque pedals were not effective. Due to obstacles he aborted his approach to the helipad and turned eastbound toward a sugar cane field. Subsequently, the helicopter started to rotate and he realized he had no control of the tail rotor with the anti torque pedals. He then rolled the throttle to idle, and initiated an autorotation from approximately 75 feet agl. The pilot further reported that a high sink rate developed and the helicopter impacted the ground hard on the main landing skids. An FAA inspector, who examined the helicopter at the accident site, reported that the main landing skids were compressed nearly flat. Further inspection revealed that the pivot bolt (P/N: NAS6604D31), bushing (P/N: 206-011-726-005), nut (P/N: MS14144l4), and cotter pin (P/N: MS24665-155), that connects the rotor control idler assembly (P/N: 406-012-127-101) to the tail rotor control housing assembly was not found. All part numbers were verified with the Bell Helicopter Textron 407 Illustrated Parts Bulletin (BHT-407-IPB). Examination of the aircraft logbooks indicated that there was an annual maintenance inspection preformed on the helicopter 7 days prior to the accident. The helicopter accumulated 4.9 hours of flight time since time of inspection. The company who preformed the maintenance inspection on the helicopter provided the NTSB investigator-in-charge with a written statement from the mechanic and supervisor who worked on the helicopter. The mechanic who was working on tail rotor gearbox area requested his supervisor inspect the area and double-check that the work was complete. It was discovered that the "pitch channel trunnion attach bolt was installed, but not tight or safety wired." The supervisor requested this be complied with. Later that day, the supervisor asked the mechanic if the work was complete, but did not verify it visually. The tail rotor gearbox cowling was then installed. ## Aircraft - Registration: [N991SP](https://openairdocs.org/deregistered/N991SP-2004-02-06), registration cancelled 2004-02-06, S/N 53518, built 2002 (OpenAirDocs) - Reported make and model: Bell 407 - Registry model: [Bell 407](https://openairdocs.org/model/bell-407) (registry code 1182206) (OpenAirDocs) - Registry engine: [Allison 250-C47 series](https://openairdocs.org/engine/allison-250-c47-series) (registry code 03029, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 53518 - Airframe hours: 203.4 - Engines: Rolls-Royce 250-C47B 800 horsepower turbo shaft - Damage: Substantial damage - Flight: Public aircraft, Public use - Registered owner: Louisiana Department of Public Safety - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 12, 2003, 4.9 hours before - Departed: BTR, BATON ROUGE, LA - Destination: Franklin ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 57; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: helicopter, airplane; medical: class 2, valid medical--w/ waivers/lim; last flight review March 14, 2002; seat: left; flight hours: 13,096 total, 305 in this make and model, 20 in the last 90 days, 12 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 72 °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 20030519011429A](https://openairdocs.org/incident/20030519011429A), May 19, 2003: Bell 407, Franklin, LA, Substantial damage. (-23) On approach to landing, pilot realized he had a tail rotor control problem. Due to obstacles, he altered his approach to a cane field for an emergency… 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.