# NTSB WPR22LA034: Bell OH-58A, N103WC, Molalla, OR, November 15, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: November 15, 2021, 08:19 local (16:19 UTC) - Place: Molalla, OR - Coordinates: 45.147285, -122.57571 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.1473&lon=-122.5757&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Unknown or undetermined](https://openairdocs.org/ntsb-events/000) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: FAA - NTSB case key (mKey): 104243 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR22LA034 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/104243/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=104243 - Page: https://openairdocs.org/ntsb/WPR22LA034 ## Probable cause The loss of engine power for undetermined reasons. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause) ## Analysis The helicopter pilot was lifting off with an external load of Christmas trees. As the helicopter climbed above 60 ft above the ground (agl), the pilot reported that he simultaneously heard a change in sound from the engine and felt the helicopter yaw, but could not remember which direction the helicopter yawed. After he released the external load, the helicopter lost altitude and he heard the main rotor speed decay. He initiated an autorotation and raised the collective while maintaining heading in the landing flare. The skids contacted the water-soaked soil and the helicopter rocked nose-low, bounced, and came to rest upright. Subsequently, the main rotor blade struck the tailboom and separated the tail rotor and tail rotor gearbox assembly. Postaccident examination of the engine revealed no evidence of any preimpact mechanical malfunction or failure that would have precluded normal operation. The engine functioned normally during two separate tests and the intermittent operation of the fuel boost pump annunciator light could not be replicated. According to the helicopter manufacturer, under the given conditions, at a gross weight of 2,350 pounds and a height of 50 feet, a hover out of ground effect can be accomplished. The reason for the loss of engine power was undetermined. ## Factual narrative On November 15, 2021, about 0819 mountain daylight time, a Bell OH-58A helicopter, N103WC, was substantially damaged when it was involved in an accident near Molalla, Oregon. The pilot was not injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 133 rotorcraft external load flight. The pilot reported that he was on an external sling load flight, relocating Christmas trees. About 30 minutes into the flight, while enroute to refuel, the master caution light and the fuel boost light illuminated. He landed the helicopter without incident. While on the ground, prior to hot refueling, he reduced the engine power setting to idle and attempted to reset the master caution light and cycled the fuel boost switch and circuit breakers, but the lights remained illuminated. After the helicopter was refueled, the pilot increased the engine power setting to 100% and recycled the fuel boost switch and circuit breakers again and the lights extinguished. The pilot added that the operator reminded him that the fuel boost light would intermittently illuminate and extinguish. The pilot then hovered the helicopter and verified that the master caution and fuel boost lights did not illuminate. Shortly after, he maneuvered the helicopter to the loading site and trees were hooked to the external sling. The pilot lifted off and as the helicopter climbed through 60 ft above the ground, he heard a change in sound from the engine and felt the helicopter yaw. Immediately after he verified that the people on the ground were clear, he released the external load. The helicopter lost altitude and the pilot heard the main rotor speed decay, so he initiated an autorotation. As the helicopter approached the ground, the pilot raised the collective while maintaining heading. The skids contacted the water-soaked soil, and the helicopter rocked nose-low, bounced, and came to rest upright. Subsequently, the main rotor blade struck the tailboom and separated the tail rotor and tail rotor gear box assembly. Postaccident examination of the engine revealed no evidence of preimpact fire or postimpact damage. Fuel continuity was established from the fuel tank to the fuel nozzle; no fuel leaks were noted. A subsequent ground idle engine run was performed. The engine was started using battery power and a normal start sequence, which included use of the airframe mounted boost pump. The engine started normally and ran at ground idle without hesitation for approximately 5 minutes. The FUEL BOOST light on the annunciator panel remained extinguished during the entire time. After 5 minutes, the fuel boost pump was turned off, the FUEL BOOST light illuminated, and the engine continued to run at ground idle with no observed anomalies for approximately 4 additional minutes. The operator reported that the fuel boost caution light illuminated randomly, independent of whether the boost pump was operating, even after the helicopter’s most recent inspection. According to thehelicopter manufacturer’s hover performance charts, at 100% N2, at a skid height of 50 ft, at a gross weight of about 2350 pounds, and at a pressure altitude of 250 ft and 15°C, the helicopter would need about 58% torque to hover. The estimated gross weight of the helicopter was 2,350 pounds. No preimpact mechanical anomalies were observed when the engine was run in a test cell using the manufacturer’s acceptance test procedure. The Fuel Control Unit was bench tested in accordance with manufacturer overhaul manual procedures and it tested successfully by meeting serviceable limits. A compressor case half was removed to facilitate visual assessment of the compressor flow path. No pre-existing conditions were found that would have precluded normal operation. A breakaway valve CT scan showed that the breakaway mechanism was intact, and the valve was open. The breakaway valve did not show any anomalies during a fuel flow test. ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Unknown or undetermined](https://openairdocs.org/ntsb-events/000) (defining event) - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092) ## Aircraft - Registration: [N103WC](https://openairdocs.org/aircraft/N103WC), registered now, S/N 1058 (OpenAirDocs) - Reported make and model: BELL OH-58A - Registry model: [Kamps Clarence M BUSHBY MUSTANG II](https://openairdocs.org/model/kamps-clarence-m-bushby-mustang-ii) (registry code 1690660) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 69-16083 - Year built: 1969 - Airframe hours: 8970.7 - Engines: Rolls Royce C20B 250 horsepower turbo shaft - Damage: Substantial damage - Flight: External load, Part 133 - Operator: Edgefield Aviation LLC - Registered owner: Edgefield Aviation LLC - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, November 14, 2021, 0.9 hours before - Departed: Sandy, OR - Destination: Same as departure - Flight plan: Company VFR - Airport: N/A - Equipment: ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 33; injuries: none; commercial; medical: class 2, without waivers/limitations; last flight review February 17, 2021; seat: right; flight hours: 3,605.6 total, 10 in this make and model, 3,517.6 as pilot in command, 32.6 in the last 90 days, 15 in the last 30 days, 0.9 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 190° at 11 knots, gusting 18 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 57 °F, dew point 50 °F - Altimeter: 29.86 inHg - Observed at: KUAO, 10 nm away - METAR: KUAO 151553Z 19011G18KT 10SM CLR 14/10 A2986 RMK AO2 SLP108 T01390100 ## Other investigations on N103WC (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB WPR24LA036](https://openairdocs.org/ntsb/WPR24LA036), Nov 15, 2023: Bell OH-58A (N103WC), Estacada, OR, substantial damage. Probable cause: The pilot’s failure to maintain helicopter control during an external load operation, which resulted in the helicopter’s main rotor blades impacting the tail boom. ## Docket (11 files) The files NTSB released with the investigation on January 4, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=104243. 13.7 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 5.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16366500&FileExtension=pdf&FileName=N103WC%20NTSB%20Accident%20Report%20Form_Redacted-Rel.pdf - Accident photo (item 2, PDF, 2 pages, 108 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16366998&FileExtension=pdf&FileName=Accident%20Photo-Rel.pdf - Pilot statement (item 3, PDF, 1 page, 67 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16393988&FileExtension=pdf&FileName=MEMORANDUM%20FOR%20RECORD%20PILOT%20034-Rel.pdf - Wreckage exam field notes (item 4, PDF, 8 pages, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16394437&FileExtension=pdf&FileName=Wreckage%20Exam%20034-Rel.pdf - Engine exam and component testing (item 5, PDF, 11 pages, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16394207&FileExtension=pdf&FileName=Engine%20Exam%20and%20Component%20Testing%20034-Rel.pdf - Breakaway valve flow test (item 6, PDF, 4 pages, 182 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16394086&FileExtension=pdf&FileName=Breakaway%20Valve%20Flow%20Test%20034-Rel.pdf - Fuel breakaway valve computed tomography specialist's factual report (item 7, PDF, 22 pages, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14709194&FileExtension=pdf&FileName=Fuel%20Breakaway%20Valve%20CT%20Report%20WPR22LA034%20-%20Final-Rel.pdf - Perfromance chart (item 8, PDF, 10 pages, 456 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16394918&FileExtension=pdf&FileName=OH-58%20Performance%20Charts-Rel.pdf - Party form (item 9, PDF, 1 page, 253 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16394124&FileExtension=pdf&FileName=Party%20Form%20034_Redacted-Rel.pdf - Evidence control form (item 10, PDF, 4 pages, 185 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16467432&FileExtension=pdf&FileName=Evidence%20Control%20Forms%20034_Redacted-Rel.pdf - Wreckage release form (item 11, PDF, 2 pages, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16467541&FileExtension=pdf&FileName=WPR22LA034%20Retention-Release-of-Wreckage-Form%20N103WC%20-%20SIGNED_Redacted-Rel.pdf From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date; 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.