# NTSB ERA12LA258: Rotorcraft Developement OH-58C, N452MC, McComb, MS, March 27, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 27, 2012, 08:12 local (13:12 UTC) - Place: McComb, MS - Coordinates: 31.173334, -90.558891 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=31.1733&lon=-90.5589&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 23, 2014 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO, Rolls-Royce - NTSB case key (mKey): 83232 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA12LA258 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/83232/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=83232 - Page: https://openairdocs.org/ntsb/ERA12LA258 ## Probable cause A total loss of engine power due to oil starvation at the Nos. 5 and 8 engine bearings, which resulted in a catastrophic engine failure. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (turbine/turboprop): oil system](https://openairdocs.org/ntsb-findings/01057261): Aircraft › Aircraft power plant · Malfunction (probable cause); cases with it: [Garlick Helicopters OH-58C, 1 case](https://openairdocs.org/ntsb-findings/01057261/cases.md?model=3740004), [All aircraft, 16 cases](https://openairdocs.org/ntsb-findings/01057261/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Garlick Helicopters OH-58C, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=3740004), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Enroute-cruise: Fire/smoke (non-impact)](https://openairdocs.org/ntsb-events/150); cases with it: [Garlick Helicopters OH-58C, 1 case](https://openairdocs.org/ntsb-events/150/sequence.md?model=3740004), [All aircraft, 504 cases](https://openairdocs.org/ntsb-events/150/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Garlick Helicopters OH-58C, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=3740004), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-flare/touchdown: Fire/smoke (non-impact)](https://openairdocs.org/ntsb-events/150); cases with it: [Garlick Helicopters OH-58C, 1 case](https://openairdocs.org/ntsb-events/150/sequence.md?model=3740004), [All aircraft, 504 cases](https://openairdocs.org/ntsb-events/150/sequence.md) ## Analysis The pilot reported that, about 3 minutes after takeoff, the helicopter yawed left. The pilot stated that he lowered the collective and initiated a descent for an autorotative landing and that the cabin then filled with smoke. He landed the helicopter uneventfully in a field and exited it. Subsequently, he noticed a fire in the engine compartment. Inspection of the engine revealed damage to the Nos. 5 and 8 bearings consistent with the reduced oil supply to the bearings during engine operation, which resulted in a catastrophic engine failure. Due to the severity of the damage to the bearing components, it could not be determined whether any preaccident malfunctions or failures existed in the bearing assembly that could have led to the reduction in the oil supply. ## Factual narrative On March 27, 2012, about 0812 central daylight time, a Rotorcraft Development Corporation OH-58C, N452MC, registered to and operated by Custom Air LLC, was substantially damaged by a fire following an uneventful forced landing in a field following loss of engine power near McComb, Mississippi. Visual meteorological conditions prevailed in the area and no flight plan was filed for the 14 Code of Federal Regulations (CFR) Part 91 positioning flight from John E. Lewis Field Airport (MCB), McComb, Mississippi, to Woodville, Mississippi. The commercial pilot, the sole occupant, was not injured. The flight originated from MCB about 3 minutes earlier. The pilot stated that approximately 3 minutes into the flight while flying at 200 feet above ground level and 100 MPH, the helicopter yawed to the left consistent with an engine failure. He lowered the collective and initiated a descent for an autorotative landing and reported the cabin filled with smoke. He landed uneventfully in a field, exited the helicopter and noticed a fire in the engine compartment area. He called his ground crew and alerted them of the forced landing. Following recovery of the helicopter, the engine and portion of the airframe was inspected by a representative of the engine manufacturer with FAA oversight. The inspection revealed shrapnel type damage to the air discharge tubes, horizontal fire shield, exhaust stacks, engine decking and main rotor blades. The inspection also noted that the extensive post landing fire damage to the accessory gearbox. Following inspection of the engine, it was then removed from the helicopter and shipped to the manufacturer's facility for teardown examination with FAA oversight. Teardown examination showed damage to the Nos. 5 and 8 bearings which was consistent with reduced oil supply to the bearings during engine operation. The third stage turbine wheel fractured and approximately 2/3's of the wheel exited the engine. Only one fragment was recovered, and metallurgical examination of the fracture by Rolls-Royce personnel revealed features were interdendritic and consistent with tensile overload. No fatigue-like fractures were observed on the fracture surfaces. Examination further indicated that the turbine module was present from the No. 3 nozzle aft and remained mated to the outer combustion case. Inspection of the turbine section revealed the gas producer and power turbine supports remained mated together with the No. 3 nozzle exposed on the forward end of the turbine module. The gas producer support was normal in appearance with no visible damage, while the power turbine support exhibited rub damage on the aft side, in an around the bore area from contact with the No. 2 wheel. The forward side exhibited impact damage from the No. 3 wheel burst around the outer flange and on the forward face of the inner bore. The No. 3 nozzle exhibited damage on the trailing edge face of the nozzle around the inner bore area and a fracture of one hub tang. Thepower turbine inner shaft was fractured just aft of the clamp nut with a segment of the shaft being retained inside the No. 4 wheel bearing bore. Inspection of the No. 8 bearing oil delivery tube pressure line "B-nut" revealed it was finger tight with no evidence of leakage; the oil delivery tube and nozzle were free of obstructions. The No. 5 bearing which was determined to be a FAA PMA part was sent to the NTSB Materials Laboratory for further examination. A copy of the engine examination report from Rolls-Royce is contained in the NTSB public docket. Examination of the No. 5 bearing was performed by the NTSB Materials Laboratory located in Washington, D.C. The results of the examination revealed the bearing cage showed evidence of severe deformation and damage. The pockets were warped into rounded T shapes with widths exceeding the maximum specified in the engineering drawing. The material on the outer face of the cage had been gouged out in a circumferential direction. Examination of the cage revealed the microhardness of the bearing cage was higher than the prescribed hardness. Further inspection of the cage revealed steel material consistent with that prescribed for the outer and inner race and balls of the bearing. Examination of the inner race of the bearing revealed the raceway showed material transfer in the form of galling and spalling, with folding and flattening of the transferred material. The inner race was lower than the prescribed hardness. Inspection of the outer race also revealed spalled areas with flattened galled material. The outer race hardness was lower than the prescribed hardness. Inspection of the bearing balls revealed only a few retained their spherical shape and original size, while the majority had deformed into prolate spheroids with deformed surfaces from spalled material. All of the balls also exhibited a surface roughness atypical for a low-friction thrust bearing, and the hardness was lower than specified. A copy of the report is contained in the NTSB public docket. ## Aircraft - Registration: [N452MC](https://openairdocs.org/deregistered/N452MC-2013-12-11), registration cancelled 2013-12-11, S/N 69-16110, built 1969 (OpenAirDocs) - Reported make and model: ROTORCRAFT DEVELOPEMENT CORP. OH-58C - Registry model: [Garlick Helicopters OH-58C](https://openairdocs.org/model/garlick-helicopters-oh-58c) (registry code 3740004) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Helicopter - Serial number: 69-16110 - Airframe hours: 8637 - Engines: Rolls-Royce 250-C20C 420 hp turbo shaft - Damage: Substantial damage - Fire: Both - Flight: Positioning, Part 91 - Operator: Custom Air LLC - Registered owner: Custom Air LLC - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, March 7, 2012 - Departed: McComb, MS - Destination: Woodville, MS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; injuries: none; commercial; medical: class 2, with waivers/limitations; last flight review April 4, 2010; seat: right; flight hours: 14,575 total, 8,554 in this make and model, 14,575 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 9 statute miles - Lowest ceiling: none - Temperature: 59 °F, dew point 55 °F - Altimeter: 30.10 inHg - Observed at: MCB ## 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 20120327004519A](https://openairdocs.org/incident/20120327004519A), Mar 27, 2012: Garlick Helicopters Inc OH-58C, Mccomb, MS, Destroyed. Inflight fire occured. The pilot reported shortly after takeoff, while in cruise the helicopter yawed to the left, the cabin filled with smoke, and the engine… ## Docket (9 files) The files NTSB released with the investigation on February 21, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=83232. 13.7 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 663 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40366537&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Materials Laboratory 15 - Factual Report of Group Chairman (item 2, .PDF, 5.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40400315&FileExtension=.PDF&FileName=Materials%20Laboratory%2015%20-%20Factual%20Report%20of%20Group%20Chairman-Master.PDF - Weather Reports and Records (item 3, .PDF, 16 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40366539&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records-Master.PDF - Reports from Parties to the Investigation-Rolls Royce (item 4, .PDF, 6.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40409668&FileExtension=.PDF&FileName=Reports%20from%20Parties%20to%20the%20Investigation-Rolls%20Royce-Redacted.PDF - FAA Inspector Statement (item 5, .PDF, 393 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40409671&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Redacted.PDF - Record of NTSB Conversation (item 6, .PDF, 53 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40409808&FileExtension=.PDF&FileName=Record%20of%20NTSB%20Conversation-Redacted.PDF - Statement of Party Representatives to NTSB Investigation (item 7, .PDF, 421 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40409664&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15, and NTSB Evidence Control Forms (item 8, .PDF, 200 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40409660&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15,%20and%20NTSB%20Evidence%20Control%20Forms-Redacted.PDF - Photo 1: Digital Photograph Provided by FAA. View of the Helicopter at the Accident Site. (item 9, .PDF, 148 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40409685&FileExtension=.PDF&FileName=Photo%201%3A%20Digital%20Photograph%20Provided%20by%20FAA.%20View%20of%20the%20Helicopter%20at%20the%20Accident%20Site.-Master.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.