# NTSB ANC01LA039: Helio H-295, N42DC, Clear, AK, March 3, 2001 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 3, 2001, 13:00 local (17:00 UTC) - Place: Clear, AK - Coordinates: 64.178611, -149.4375 - Nearby events: https://openairdocs.org/map.md?lat=64.1786&lon=-149.4375&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report July 2, 2002 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration - NTSB case key (mKey): 51858 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC01LA039 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/51858/pdf - Page: https://openairdocs.org/ntsb/ANC01LA039 ## Probable cause The shifting of engine connecting rod bearings, and the fracture of an engine connecting rod. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - mech failure/malf, cruise - normal - engine assembly,connecting rod - fractured (cause) - engine assembly,bearing - shifted (cause) - Forced landing, emergency descent/landing - In flight collision with object, emergency descent/landing - object - tree(s) ## Analysis The certificated airline transport pilot reported that while in level, cruise flight, the engine began to run rough and lose power. The pilot said that while performing the engine emergency procedures, he smelled smoke in the cabin, and noted a substantial amount of engine oil on the windscreen. The airplane collided with trees during a subsequent forced landing. A postaccident investigation revealed that the number two connecting rod had sustained a complete fracture. The number 2 connecting rod journal displayed significant amount of heat induced bluing. The fractured connecting rod, main journal bearing shells (7 halves), and rod bearing shells (7 halves) were sent to the NTSB's Materials Laboratory for examination. A Senior Safety Board metallurgist reported that the separated connecting rod displayed evidence of low cycle, high stress fatigue cracking. A scanning electron microscope (SEM) examination of the rod bearing shells disclosed pitting, with irregular-shape metal particles embedded on the surface of the bearing material. The area around the pits showed evidence of metallic flow from the pits. ## Factual narrative On March 3, 2001, about 1300 Alaska standard time, a wheel/ski equipped Helio H-295 airplane, N42DC, sustained substantial damage during a forced landing about 20 miles south of Clear, Alaska. The airplane was being operated as a visual flight rules (VFR) positioning flight under Title 14, CFR Part 91, when the accident occurred. The airplane was registered to, and operated by, Wright Air Service, Inc., Fairbanks, Alaska. The solo airline transport pilot was not injured. Visual meteorological conditions prevailed, and a VFR flight plan was filed. The flight originated about 1245, from the Stampede Airstrip, located about 37 miles west of Healy, Alaska, and was en route to Fairbanks. During a telephone conversation with the National Transportation Safety Board investigator-in-charge on March 5, the pilot reported that while in level, cruise flight, the engine began to run rough and lose power. The pilot said that while performing the engine emergency procedures, he smelled smoke in the cabin, and noted a substantial amount of engine oil on the windscreen. The airplane collided with trees during a subsequent forced landing, and sustained substantial damage to the wings, fuselage, and empennage. The pilot stated that a postaccident inspection revealed a fist-sized hole on the left side of the engine crankcase. The director of maintenance for the operator reported that at the time of the accident, the engine had accrued a total time in service of 1,143.0 hours since overhaul, and was installed in the accident airplane in late August of 1999. The engine maintenance records note that the engine was "overhauled" and reassembled per Lycoming overhaul manual 60294-5-6 on August 17, 1999. All work was performed by the operator, at the operator's maintenance facility, in Fairbanks. The airplane was eventually recovered by the operator and insurance personnel, and moved to the operator's maintenance facility in Fairbanks. On April 12, 2001, in the presence of a Federal Aviation Administration (FAA) airworthiness inspector from the Fairbanks Flight Standards District Office, an engine tear down and inspection was conducted at the operator's maintenance facility in Fairbanks. According to the FAA inspector, the inspection revealed that the number two connecting rod had sustained a complete fracture. The fracture surfaces displayed postfailure circumferential scoring, and damage. In addition, the FAA inspector noted a significant amount of heat induced, bluing of the number 2 connecting rod journal. The fractured connecting rod, main journal bearing shells (7 halves), and rod bearing shells (7 halves) were sent to the National Transportation Safety Board's Materials Laboratory for examination. A Senior Safety Board metallurgist reported that the separated connecting rod displayed evidence of low cycle, high stress fatigue cracking. He noted that a scanning electron microscope (SEM) examination of the rod bearing shells disclosed irregular-shape metal particles that were embedded on the surface of the bearing material. He added that the rod bearing shells displayed many pits. The area around the pits showed evidence of metallic flow from the pits. ## Aircraft - Registration: [N42DC](https://openairdocs.org/deregistered/N42DC-2001-08-15), registration cancelled 2001-08-15, S/N 1454 (OpenAirDocs) - Reported make and model: Helio H-295 - Registry model: [Helio H-295](https://openairdocs.org/model/helio-h-295) (registry code 4300802) (OpenAirDocs) - Category: Airplane - Serial number: 1454 - Airframe hours: 7519 - Engines: Lycoming GO-480-G1D6 295 horsepower reciprocating - Damage: Substantial damage - Flight: Positioning, Part 91 - Registered owner: Wright Air Service,Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, December 15, 2000, 96 hours before - Departed: Z90, Stampede, AK - Destination: FAI, Fairbanks, AK - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; injuries: none; airline transport, flight engineer; airplane ratings: multi-engine land, single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; last flight review December 31, 2000; seat: left; flight hours: 18,800 total, 5,500 in this make and model, 18,300 as pilot in command, 100 in the last 90 days, 30 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 100 statute miles - Lowest ceiling: none - Temperature: 5 °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 20010303002509A](https://openairdocs.org/incident/20010303002509A), Mar 3, 2001: Helio H295, No damage. (-23) During cruise flight the pilot reported that the engine started to run rough and shake excessively, at which time the pilot said that the throttle was… ## Other investigations on N42DC (2) 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 ANC94LA046](https://openairdocs.org/ntsb/ANC94LA046), Apr 8, 1994: Helio 295 (N42DC), Manley Hot Sprg, AK, substantial damage. Probable cause: FUEL STARVATION CAUSED BY A BLOCKED FUEL VENT LINE. A FACTOR IN THE ACCIDENT WAS THE IMPROPER AIRCRAFT PREFLIGHT. - [NTSB ANC93LA154](https://openairdocs.org/ntsb/ANC93LA154), Aug 15, 1993: Helio H-295 (N42DC), Mt. Deborah, AK, substantial damage. Probable cause: FAILURE OF THE RIGHT MAIN LANDING GEAR LEG DUE TO THE IMPROPER MAJOR REPAIR PERFORMED ON THE GEAR LEG BY SOME UNKNOWN MAINTENANCE PERSON(S). 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.