# NTSB FTW98LA084: Hughes 269C, N1091Y, Riviera, TX, January 2, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: January 2, 1998, 08:30 local (14:30 UTC) - Place: Riviera, TX - Coordinates: 27.280019, -97.809707 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=27.2800&lon=-97.8097&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 16, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 20510 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW98LA084 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20510/pdf - Page: https://openairdocs.org/ntsb/FTW98LA084 ## Probable cause The total loss of engine power due to a fatigue failure of the crankshaft for undetermined reason. A factor was the lack of suitable terrain for the forced landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, maneuvering - engine assembly,crankshaft - fatigue (cause) - reason for occurrence undetermined (cause) - Forced landing, emergency descent/landing - terrain condition - none suitable (contributing factor) - object - tree(s) ## Analysis Following a total loss of engine power, during a cattle herding flight, the pilot executed an autorotation to an area confined by trees. Engine examination revealed a broken crankshaft & camshaft. The camshaft exhibited deformation consistent with overload. All four cylinder mounting flanges were fretted & all piston rings showed 'excessive' wear. The #1 & #4 cylinder top compression rings were broken. Main bearing saddle faces of the crankcase showed heavy fretting. The engine manufacturer Materials Laboratory reported the mode of fracture of the crankshaft was fatigue. The fatigue originated from the oil hole (between #3 main & #3 crankpin journals) in the cheek and near the rear fillet radius of the #3 main bearing journal. The cause of the fatigue was not determined. During the overhaul, the crankshaft received a magnaflux inspection & re-nitriding by an inspection facility. The engine was reassembled & returned to service by company maintenance personnel. The engine had 1150.6 hours since overhaul. ## Factual narrative On January 2, 1998, at 0830 central standard time, a Hughes 269C helicopter, N1091Y, owned and operated by Smith Helicopters, Inc., under Title 14 CFR Part 91, sustained substantial damage during an autorotation following a loss of engine power while maneuvering near Riviera, Texas. The commercial pilot and the passenger were not injured. Visual meteorological conditions prevailed for the local cattle herding flight and a flight plan was not filed. The flight originated from the King Ranch at 0745. During telephone interviews, conducted by the investigator-in-charge (IIC), and on the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), the pilot and the operator reported that the pilot was maneuvering the helicopter at 75 feet agl herding cattle on the King Ranch when the engine "started missing briefly then quit." The pilot executed an autorotation to a dirt road confined by mesquite trees 15 to 20 feet in height. During the landing, the main rotor struck the tailboom. The tailboom, vertical and horizontal stabilizer, main rotor blades, and the tail rotor driveshaft received structural damage. A review of the engine maintenance records, by the FAA inspector and the IIC, revealed that the Lycoming HIO-360-D1A engine, S/N L-25772-51A, was manufactured in 1991. The engine was overhauled in January 1995. During the engine overhaul, the crankshaft received a magnaflux inspection and re-nitriding. The crankshaft was certified and approved for return to service by Aircraft Engine & Accessory Co., Inc., Dallas, Texas. The engine was reassembled by a mechanic and installed in N1091Y. The engine was returned to service by company maintenance personnel on February 21, 1995. At the time of the accident, the engine time since overhaul was 1,150.6 hours. The last 100 hour inspection was performed on October 7, 1997, and the airplane had accumulated 69 hours since the inspection. On March 10, 1998, at Laredo, Texas, the FAA inspector examined the helicopter and the engine. Structural damage to the airframe was confirmed. The inspector reported that the engine crankshaft would not rotate. When cylinders #1 and #3 were removed from the engine, the FAA inspector found that a portion of the crankshaft appeared to be separated in the area of the #3 main bearing. A piece of metal was found in the oil screen sump. The engine was shipped to Textron Lycoming, Williamsport, Pennsylvania, for further examination. On September 16, 1998, in Williamsport, Pennsylvania, under the surveillance of an FAA inspector, a teardown of the engine revealed a broken crankshaft and camshaft. The camshaft exhibited deformation consistent with overload. All four cylinder mounting flanges were fretted and all piston rings showed "excessive" wear. The #1 and the #4 cylinder top compression rings were broken. The engine and aircraft logs provided no indications as to what service bulletins or FAA Airworthiness Directives had been complied with from overhaul to the time of the accident. The #1, #2, and the #3 center main bearing saddle faces of the crankcase showed heavy fretting. Fresh fretting was seen on the #4 main saddle surface. The oil holes and galleys were normal. See the enclosed reports for additional details. The crankshaft was examined by the Textron Lycoming Materials Laboratory. The mode of fracture of the crankshaft was fatigue. The fatigue originated from the oil hole (between #3 main and #3 crankpin journals) in the cheek and near the rear fillet radius of the #3 main bearing journal. The cause of the fatigue was not determined. The helicopter was released to the owner's representative. ## Aircraft - Registration: [N1091Y](https://openairdocs.org/deregistered/N1091Y-2013-08-27), registration cancelled 2013-08-27, S/N 411050, built 1981 (OpenAirDocs) - Reported make and model: Hughes 269C - Registry model: [Hughes 269C](https://openairdocs.org/model/hughes-269c) (registry code 4470504) (OpenAirDocs) - Registry engine: [Lycoming HIO-360 series](https://openairdocs.org/engine/lycoming-hio-360-series) (registry code 41524, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 411050 - Airframe hours: 6631 - Engines: Lycoming HIO-360-D1A 190 horsepower reciprocating - Damage: Substantial damage - Flight: Other work use, Part 91 - Registered owner: Smith Helicopters, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, October 7, 1997, 69 hours before ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 28; commercial; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 567 total, 567 in this make and model, 527 as pilot in command, 254 in the last 90 days, 61 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 135° at 5 knots - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 68 °F ## 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 19980102000039A](https://openairdocs.org/incident/19980102000039A), Jan 2, 1998: Hughes 269C, Riviera, TX, Substantial damage. Engine quit while herding cattle. Autorotated to hard landing main rotors chopped tail boom. (.4)following a total loss of engine power, during a cattle… 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.