# NTSB ERA11IA521: Beech V35, N275BM, New Haven, CT, September 18, 2011 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: September 18, 2011, 10:35 local (14:35 UTC) - Place: New Haven, CT - Coordinates: 41.26361, -72.888885 - Nearby events: https://openairdocs.org/map.md?lat=41.2636&lon=-72.8889&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-climb to cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 14, 2013 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: Continental Motors Inc., FAA/FSDO - NTSB case key (mKey): 82934 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA11IA521 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/82934/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=82934 - Page: https://openairdocs.org/ntsb/ERA11IA521 ## Probable cause The in-flight fatigue failure of the engine’s crankshaft, which resulted in the separation of the forward portion of the crankshaft and the propeller. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng front section](https://openairdocs.org/ntsb-findings/01058510): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [Beech V35, 1 case](https://openairdocs.org/ntsb-findings/01058510/cases.md?model=1151538), [All aircraft, 13 cases](https://openairdocs.org/ntsb-findings/01058510/cases.md) - [Propeller system: propeller assembly](https://openairdocs.org/ntsb-findings/01046110): Aircraft › Aircraft propeller/rotor · Not specified; cases with it: [Beech V35, 1 case](https://openairdocs.org/ntsb-findings/01046110/cases.md?model=1151538), [All aircraft, 29 cases](https://openairdocs.org/ntsb-findings/01046110/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-climb to cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Beech V35, 3 cases](https://openairdocs.org/ntsb-events/340/sequence.md?model=1151538), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Enroute-climb to cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Beech V35, 10 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=1151538), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Beech V35, 9 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=1151538), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Beech V35, 3 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=1151538), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## Analysis During the climb after takeoff, as the airplane approached 6,000 feet mean sea level, the crankshaft fractured, and the airplane experienced a total loss of engine power. The forward portion of the crankshaft, with the propeller attached, departed the engine. The pilot declared an emergency and returned to the departure airport where he performed a forced landing on a runway. The airplane sustained minor nose gear damage when it overran the runway. Examination of the crankshaft revealed that it was fractured across the No. 4 main journal. Metallurgical examination revealed cracks that initiated on the bearing surface near an oil transfer tube and propagated in fatigue. At the time of the incident, the engine had been operated for about 910 total hours, about 500 hours of which had occurred since maintenance, which was performed about 2 1/2 years before the incident and included the reinstallation of the Nos. 2 and 4 cylinders. The crankcase adjacent to the fractured portion of the crankshaft showed significant fretting on the mating surfaces, possibly due to incorrect torque applied during the previous cylinder repair; however, the investigation could not determine the relevance of that repair, if any, due to the time that had elapsed since the repair was completed. ## Factual narrative On September 18, 2011, about 1035 eastern daylight time, a Beech V35, N275BM, operated by a commercial pilot, sustained minor damage during a forced landing, following a total loss of engine power shortly after takeoff from the Tweed-New Haven Airport (HVN), New Haven, Connecticut. The certificated commercial pilot and a passenger were not injured. Visual meteorological conditions prevailed and an instrument flight rules flight plan was filed for the personal flight that was conducted under the provisions of 14 Code of Federal Regulations Part 91. According to the pilot, the airplane departed HVN and began to climb without incident. As the airplane approached 6,000 feet mean sea level, the pilot felt a shutter and slight change in engine rpm. A few seconds later, he experienced oil on the windscreen, smoke, and engine roughness, followed by a total loss of engine power. The pilot declared an emergency and was able to return to HVN to perform a forced landing to runway 14. During the landing, the airplane sustained minor nose gear damage when it overran the runway about 50 feet, and came to rest in weeds. The airplane was powered by a Teledyne Continental Motors IO-550-B83, 300-horsepower engine, equipped with a three-bladed Hartzell constant-speed propeller. Examination of the airplane by a Federal Aviation Administration inspector revealed that the propeller and forward portion of the crankshaft, aft of the propeller mounting flange, separated inflight and was subsequently located in a wooded area. The engine and the separated portion of the crankshaft were retained for further examination. A teardown of the engine conducted at Continental Motors Inc., Mobile, Alabama, under the supervision of an NTSB investigator, revealed that the crankshaft and counterweight assembly exhibited lubrication distress, thermal damage, and mechanical damage on all six connecting rod journals. The crankshaft was fractured in two-pieces across the No. 4 main journal. The crankcase main bearing supports adjacent to the fracture exhibited fretting signatures and lock-slot elongation. The No. 4 main bearing was extruded, with portions found in the oil sump. Metallurgical examination of the fractured crankshaft revealed cracks initiated on the bearing surface near an oil transfer tube and propagated in fatigue. Cracks were also identified on the bearing fillet radius. At the time of the incident, the airplane had been operated for about 5,470 total hours, and 14 hours since its most recent annual inspection, which was performed on August 11, 2011. The engine was manufactured during November 2006, and had been operated for about 910 total hours. In addition, the engine had been operated for about 500 hours since maintenance was performed that included the reinstallation of the Nos. 2 and 4 cylinders after repair, on February 17, 2009. ## Aircraft - Registration: [N275BM](https://openairdocs.org/aircraft/N275BM), registered now, S/N D-8196, built 1966 (OpenAirDocs) - Reported make and model: BEECH V35 - Registry model: [Beech V35](https://openairdocs.org/model/beech-v35) (registry code 1151538) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: D-8196 - Airframe hours: 5470 - Engines: CONT MOTOR IO-550-B 300 horsepower reciprocating - Damage: Minor damage - Flight: Personal, Part 91 - Operator: Westchester Flying Club, Inc. - Registered owner: David C. Nelson - Airworthiness certificate: Standard, Utility - Last inspection: Annual, August 11, 2011, 14 hours before - Departed: HVN, New Haven, CT - Destination: MMU, Morristown, NJ - Flight plan: IFR - Airport: HVN, Tweed-New Haven, runway 14, 3,626 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review August 12, 2010; seat: left; flight hours: 660 total, 120 in this make and model, 590 as pilot in command, 29 in the last 90 days, 22 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 60° at 10 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 64 °F, dew point 52 °F - Altimeter: 30.42 inHg - Observed at: HVN ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Incident 20110918022109I](https://openairdocs.org/incident/20110918022109I), Sep 18, 2011: Beech V35, East Haven, CT, Minor damage. N275BM, bonanza, BE-V35 departed tweed-new Haven airport (bdr) new Haven, CT approx 10AM 18 sep 2011, on runway 2 and cleared to 6000 feet at 330 degrees. Upon… ## Docket (11 files) The files NTSB released with the investigation on December 19, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=82934. 46.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382710&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Metallurgical Examination Report (item 2, .PDF, 6 photos, 293 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382712&FileExtension=.PDF&FileName=Metallurgical%20Examination%20Report-Master.PDF - Engine Maintenance Records (item 3, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40383525&FileExtension=.PDF&FileName=Engine%20Maintenance%20Records-Redacted.PDF - Statement of Party Representatives to NTSB Investigation (item 4, .PDF, 222 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382711&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Photograph # 1 – Front of the engine prior to disassembly (item 5, .PDF, 6.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40383513&FileExtension=.PDF&FileName=Photograph%20%23%201%20%E2%80%93%20Front%20of%20the%20engine%20prior%20to%20disassembly%20-Master.PDF - Photograph # 2 – Damage to top of engine crankcase (item 6, .PDF, 6.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40383514&FileExtension=.PDF&FileName=Photograph%20%23%202%20%E2%80%93%20Damage%20to%20top%20of%20engine%20crankcase-Master.PDF - Photograph # 3 – Separated portion of the crankshaft with a portion of the crankcase attached (item 7, .PDF, 5.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40383517&FileExtension=.PDF&FileName=Photograph%20%23%203%20%E2%80%93%20Separated%20portion%20of%20the%20crankshaft%20with%20a%20portion%20of%20the%20crankcase%20attached-Master.PDF - Photograph # 4 – Separated portion of the crankshaft (item 8, .PDF, 5.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40383518&FileExtension=.PDF&FileName=Photograph%20%23%204%20%E2%80%93%20Separated%20portion%20of%20the%20crankshaft-Master.PDF - Photograph # 5 – Debris found in oil sump (item 9, .PDF, 8.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40383520&FileExtension=.PDF&FileName=Photograph%20%23%205%20%E2%80%93%20Debris%20found%20in%20oil%20sump-Master.PDF - Photograph # 6 – View of fretting on No.4 crankcase main bearing support (Right Side) (item 10, .PDF, 5.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40383521&FileExtension=.PDF&FileName=Photograph%20%23%206%20%E2%80%93%20View%20of%20fretting%20on%20No.4%20crankcase%20main%20bearing%20support%20(Right%20Side)%20-Master.PDF - Photograph # 7 – View of fretting on No.4 crankcase main bearing support (Left Side) (item 11, .PDF, 5.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40383522&FileExtension=.PDF&FileName=Photograph%20%23%207%20%E2%80%93%20View%20of%20fretting%20on%20No.4%20crankcase%20main%20bearing%20support%20(Left%20Side)%20-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.