# NTSB ERA23LA319: Bell Helicopter Textron Canada 407, N31PB, North Charleston, SC, August 1, 2023 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: August 1, 2023, 15:30 local (19:30 UTC) - Place: North Charleston, SC · Off side of runway 15, in grass - Coordinates: 32.90605, -80.04328 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.9061&lon=-80.0433&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR pattern final: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO, Bell Helicopter, Transportation Safety Board of Canada - NTSB case key (mKey): 192772 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA23LA319 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192772/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=192772 - Page: https://openairdocs.org/ntsb/ERA23LA319 ## Probable cause A failure of the tail rotor pitch change lever assembly due to incorrectly installed bolts and maintenance personnel’s inadequate inspection of the tail rotor control system. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Flight control system](https://openairdocs.org/ntsb-findings/01022700): Aircraft › Aircraft systems · Inadequate inspection (probable cause); cases with it: [Bell Helicopter Textron Canada 407, 1 case](https://openairdocs.org/ntsb-findings/01022700/cases.md?model=1182154), [All aircraft, 65 cases](https://openairdocs.org/ntsb-findings/01022700/cases.md) - [Inspection: scheduled/routine inspection](https://openairdocs.org/ntsb-findings/02061520): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Bell Helicopter Textron Canada 407, 2 cases](https://openairdocs.org/ntsb-findings/02061520/cases.md?model=1182154), [All aircraft, 167 cases](https://openairdocs.org/ntsb-findings/02061520/cases.md) - [Maintenance](https://openairdocs.org/ntsb-findings/02062000): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Bell Helicopter Textron Canada 407, 1 case](https://openairdocs.org/ntsb-findings/02062000/cases.md?model=1182154), [All aircraft, 143 cases](https://openairdocs.org/ntsb-findings/02062000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-VFR pattern final: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) (defining event); cases with it: [Bell Helicopter Textron Canada 407, 3 cases](https://openairdocs.org/ntsb-events/333/sequence.md?model=1182154), [All aircraft, 410 cases](https://openairdocs.org/ntsb-events/333/sequence.md) - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Bell Helicopter Textron Canada 407, 4 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=1182154), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis The pilot reported that, about 35 minutes into the flight, he noticed that the helicopter began to yaw to the right and his pedal inputs did not correct the situation. He contacted the tower at his destination and declared an emergency. As he approached the runway for a straight-in landing, the helicopter yawed again. He lowered the collective, but the helicopter continued to yaw right. He then reduced the throttle and attempted to maintain a level attitude. The helicopter struck the ground at a high rate of descent, coming to rest in the grass adjacent to runway. The helicopter sustained substantial damage to the fuselage, main rotor system, and tail rotor system. A postaccident examination of the helicotper found one of the two bolts that secured the tail rotor pitch change lever assembly was missing. The lever assembly was disconnected from the trunnion, resulting in the loss of tail rotor control. The other bolt that connected the levers to the rod assembly was in place, but loose; the cotter pin for its attachment nut was missing. A review of the maintenance records revealed that a 300 hour/3 month inspection was performed on the helicopter about 15.4 flight hours before the accident. According to the helicopter manufacturer, that recent inspection would not have required removal of the lever assembly bolts; however, the nuts and bolts should have been clearly visible during the inspection of the area. The mechanic who performed the inspection stated that he must have overlooked them. ## Factual narrative On August 1, 2023, about 1530 eastern daylight time, a Bell Helicopter Textron Canada 407, N31PB, was substantially damaged when it was involved in an accident near North Charleston, South Carolina. The commercial pilot sustained minor injuries. The helicopter was operated as a public aircraft. The helicopter, operated by the Charleston County Sheriff’s Office, was on a positioning flight from Sumter Airport (SMS), Sumter, South Carolina, to Charleston AFB International Airport (CHS), North Charleston, South Carolina. The pilot reported that, after about 35 minutes of flight, the helicopter started to yaw slowly to the right. The pilot applied left pedal with no response. The pilot stated, “It felt as if the pedals were not attached.” He contacted CHS tower and declared an emergency. He set up for a straight-in approach to runway 15. While crossing the runway threshold, about 20 ft above ground level, the helicopter started to yaw to the right. He lowered the collective, but the helicopter continued to yaw right. He then reduced the throttle and attempted to maintain a level attitude. The helicopter struck the ground adjacent to runway 15 at a high rate of descent, coming to rest in the grass. The tail rotor boom severed during the impact sequence. Inspectors with the Federal Aviation Administration (FAA) responded to the accident site and examined the wreckage. They confirmed substantial damage to the fuselage, main rotor system, and tail rotor system. They found 1 of the 2 bolts that secured the tail rotor pitch change lever assembly was missing (Photo 1). The lever assembly was disconnected from the trunnion. The other bolt that connected the levers to the rod assembly was in place, but loose; the cotter pin for its attachment nut was missing (Photo 2). Photo 1: Tail rotor Pitch Change Lever Assembly. Red arrow points to area of missing bolt. Photo 2: Pitch Change Lever Assembly. Red arrow points to loose nut on bolt; cotter pin was missing. A review of the maintenance records by FAA inspectors revealed that a 300 hour/3 month inspection was performed on the helicopter on June 28, 2023. The helicopter had been flown about 15.4 hours since this inspection. According to Bell Helicopter technical support personnel, the inspection/lubrication procedure that was accomplished on June 28 would not require removal of the lever assembly bolts; however, the nuts and bolts should have been clearly visible during the inspection of the area. The mechanic who performed the inspection stated that he must have overlooked them. ## Aircraft - Registration: [N31PB](https://openairdocs.org/deregistered/N31PB-2025-12-06), registration cancelled 2025-12-06, S/N 54321, built 2012 (OpenAirDocs) - Reported make and model: BELL HELICOPTER TEXTRON CANADA 407 - Registry model: [Bell Helicopter Textron Canada 407](https://openairdocs.org/model/bell-helicopter-textron-canada-407) (registry code 1182154) (OpenAirDocs) - Registry engine: [Rolls-Royce 250-C47B](https://openairdocs.org/engine/rolls-royce-250-c47b) (registry code 54585, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 54321 - Year built: 2012 - Airframe hours: 4617 - Engines: Rolls-Royce C47B turbo shaft - Damage: Substantial damage - Flight: Positioning, Public use - Operator: Charleston County Sheriff's Office - Registered owner: County Of Charleston - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 28, 2023, 15 hours before - Departed: SMS, Sumter, SC - Destination: Same as departure - Airport: CHS, Charleston AFB International, runway 15, 9,001 × 150 ft, concrete - Equipment: Electronic primary flight display, Electronic multifunction display, Auto-pilot, ADS-B, Onboard weather ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 57; injuries: minor; commercial; airplane ratings: single-engine land; instrument ratings: airplane, helicopter; medical: class 2, with waivers/limitations; last flight review February 2, 2022; seat: right; flight hours: 3,743 total, 333 in this make and model, 3,505 as pilot in command, 15 in the last 90 days, 7 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 110° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: 5,500 ft broken - Temperature: 88 °F, dew point 72 °F - Altimeter: 30.03 inHg - Observed at: KCHS - METAR: KCHS 011956Z 11009KT 10SM SCT045 BKN055 31/22 A3003 RMK AO2 SLP169 T03110222 ## 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 20230801008179A](https://openairdocs.org/incident/20230801008179A), Aug 1, 2023: Bell Helicopter Textron Canada 407, North Charlesto, SC, Substantial damage. On August 1, 2023 at approximately 1530 hours (local), a Bell helicopter 407 was substantially damaged in an accident at the Charleston international airport… ## Other investigations on N31PB (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 ERA12TA251](https://openairdocs.org/ntsb/ERA12TA251), Mar 23, 2012: Bell 407 (N31PB), Delray Beach, FL, substantial damage. Probable cause: The pilot’s improper response to a simulated engine failure and the instructor’s delayed and improper remedial action. ## Docket (5 files) The files NTSB released with the investigation on May 9, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=192772. 11.3 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16294100&FileExtension=pdf&FileName=1%206120_Redacted-Rel.pdf - FAA inspector statement (item 2, PDF, 2 pages, 66 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16293969&FileExtension=pdf&FileName=2%20FAA%20Inspectors%20Statement%20N31PB-Rel.pdf - Excerpts - maintenance records (item 3, PDF, 5 pages, 7.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16293638&FileExtension=pdf&FileName=4%20Excerpts%20-%20Maintenance%20Records_Redacted-Rel.pdf - Investigation photographs (item 4, PDF, 7 pages, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16293745&FileExtension=pdf&FileName=5%20Investigation%20Photographs-Rel.pdf - Bell 407 tail rotor information (item 5, PDF, 2 pages, 222 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16294110&FileExtension=pdf&FileName=6%20Tail%20Rotor%20Information-Rel.pdf 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.