# NTSB ERA19LA258: Beech F33, N80WH, Hobe Sound, FL, August 23, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: August 23, 2019, 09:46 local (13:46 UTC) - Place: Hobe Sound, FL - Coordinates: 27.032777, -80.111389 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=27.0328&lon=-80.1114&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: 3 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Eastern Region Aviation - Parties: FAA / FSDO, Continental Aerospace Technologies - NTSB case key (mKey): 100131 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA19LA258 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100131/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100131 - Page: https://openairdocs.org/ntsb/ERA19LA258 ## Probable cause A bearing shift, which resulted in a loss of lubrication to the crankshaft, the failure of the crankshaft, and a total loss of engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip engine power section](https://openairdocs.org/ntsb-findings/01058520): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Beech F33A, 1 case](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=1151425), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/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: [Beech F33A, 14 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=1151425), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) ## Analysis During low-altitude cruise flight, the engine lost total power and the pilot performed a forced landing on an embankment next to a road, resulting in substantial damage to the right wing, right tip tank, and right elevator. Postaccident examination of the engine revealed that the crankshaft was fractured between the No. 2 main bearing journal and the No. 2 connecting rod journal and exhibited evidence of lubrication distress. Additionally, the No. 2 bearing had shifted, and a large portion of the bearing had extruded from the bearing support. The bearing support mating surfaces displayed fretting and the lock tab had completely worn away. Based on the observed damage, it is likely that the No. 2 main bearing shifted, resulting in inadequate lubrication to, and subsequent failure of, the crankshaft. While the crankcase mating surfaces displayed unapproved sealant material with no signs of silk thread, which was not consistent with the engine manufacturer’s guidance for engine assembly, the breakaway through bolt torque remained at or above the manufacturer’s specification. It could not be definitively determined, based on available evidence, if the use of an unapproved sealant contributed to the bearing shift. ## Factual narrative On August 23, 2019, about 0946 eastern daylight time, a Beech, F33A, N80WH, was substantially damaged when it was involved in an accident near Hobe Sound, Florida. The private pilot and two passengers were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that his preflight inspection of the airplane revealed no anomalies and that he departed on the flight to look at properties. While in cruise flight, he heard a “tap, tap, tap, tap and a bang” and recalled the engine oil pressure gauge reading 0. The airplane was below 1,000 ft mean sea level (msl), and he began looking for a forced landing site. The pilot flew under powerlines, performed a forced landing on the embankment next to the roadway, and the airplane continued to slide until it came to rest. The airplane sustained substantial damage to the right wing, right tip tank, and right elevator. According to the airframe maintenance logbook, the airplane’s most recent annual inspection was completed on April 21, 2018, at a total time of 4,591.2 hours. The most recent 100-hour inspection was completed on May 17, 2019, at an aircraft total time of 4,670.6 hours. At that time, the oil and oil filter were replaced. The logbook entry included that the filter was cut open and “no defects were noted.” The aircraft total time at the time of the accident was 4,674.7 hours. According to the engine logbook, the engine had accrued 1,139.1 hours since it was overhauled on August 1, 2004. Examination of the engine revealed that the engine crankcase displayed a crack near the aft section of the spine. All 12 through bolt torque values were above the manufacturer's recommended torque values of 490 to 510 in-lbs torque. The outer crankcase mating surfaces displayed evidence of an unapproved sealant material with no signs of silk thread. The area around the Nos. 1 and 2 bearing support through bolt holes displayed a significant amount of fretting between the mating surfaces, while the Nos. 3 and 4 bearing support mating surfaces also displayed some fretting. The No. 1 bearing support displayed minor lock tab elongation, while the No. lock tab had completely worn away. The Nos. 1 and 2 bearings displayed signatures consistent with bearing shift, with the No. 2 bearing displaying the most movement. A large portion of the No. 2 bearing had extruded from the bearing support. The crankshaft was fractured between the No. 2 main bearing journal and the No. 2 connecting rod journal. Both sides of the crankshaft fracture surface exhibited thermal discoloration and incipient signatures of lubrication distress. The maintenance and overhaul manual for the IO-550-B engine described the proper assembly procedures. This section provided part numbers for approved sealant and grade silk thread to be used during assembly. The manual also warned against using unapproved sealants, stating: WARNING Do not apply any form of sealant to the crankcase cylinderdeck, chamfer, cylinder mounting flange, cylinder base O-ring, cylinder fastener threads or crankcase main bearing bosses. The use of RTV, silicone, Gasket Maker or any other sealant on the areas listed above during engine assembly will cause a loss of cylinder deck stud or through-bolt torque. Subsequent loss of cylinder attachment load, loss of main bearing crush and/or fretting of the crankcase parting surfaces will occur. The result will be cylinder separation, main bearing movement, oil starvation and catastrophic engine failure. USE ONLY CLEAN 50 WEIGHT AVIATION ENGINE OIL ON SURFACES LISTED. ## Aircraft - Registration: [N80WH](https://openairdocs.org/deregistered/N80WH-2020-04-02), registration cancelled 2020-04-02, S/N CE-504, built 1974 (OpenAirDocs) - Reported make and model: Beech F33 (A) - Registry model: [Beech F33A](https://openairdocs.org/model/beech-f33a) (registry code 1151425) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: CE-504 - Year built: 1974 - Airframe hours: 4674.7 - Engines: Continental IO-550B 300 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Utility - Last inspection: Annual, May 17, 2019, 4 hours before - Departed: SUA, Stuart, FL - Destination: SUA, Stuart, FL - Equipment: Electronic multifunction display, Auto-pilot, ADS-B, Stall warning system, Onboard weather, Handheld GPS, Electronic primary flight display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 76; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review June 9, 2019; seat: left; restraint: 4-point; flight hours: 3,037.6 total, 2,339.6 in this make and model, 2,991.8 as pilot in command, 4 in the last 90 days, 0.5 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 110° at 12 knots - Visibility: 7 statute miles - Lowest ceiling: 2,300 ft broken - Temperature: 86 °F, dew point 77 °F - Altimeter: 30.00 inHg - Observed at: SUA, 11 nm away ## 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 20190823012039A](https://openairdocs.org/incident/20190823012039A), Aug 23, 2019: Beech F33A, Hobe Sound, FL, Substantial damage. Aircraft landed gear up in the north bound lanes of federal highway and came to rest pointing south east. Examination of the road way revealed ground scares on… ## Docket (8 files) The files NTSB released with the investigation on April 14, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100131. 69.5 MB in all. - Pilot aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12081359&FileExtension=pdf&FileName=NTSB%206120_N80WH_Redacted-Rel.pdf - Pilot interview (item 2, PDF, 1 page, 162 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12082047&FileExtension=pdf&FileName=Memorandum%20for%20Record-Pilot%20interview%20ERA19LA258-Rel.pdf - Engine examination report (item 3, PDF, 36 pages, 53.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12081975&FileExtension=pdf&FileName=19-072%20N80WH%20Engine%20Examination%20Report_Redacted-Rel.pdf - Engine and aircraft logbooks (item 4, PDF, 17 pages, 8.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12083829&FileExtension=pdf&FileName=Logbooks%20_Redacted-Rel.pdf - Excerpts from Continental motors engine IO-550-B maintenance and overhaul manual (item 5, PDF, 10 pages, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12082057&FileExtension=pdf&FileName=Continental%20Aircraft%20Engines%20IO-550-B%20Maintenance%20%26%20Overhaul%20Manual-Rel.pdf - Continental - service bulliten SB03-3 (item 6, PDF, 9 pages, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12084103&FileExtension=pdf&FileName=SB03-3%20Service%20Bulletin-Rel.pdf - Investigative photographs (item 7, PDF, 3 pages, 649 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12081846&FileExtension=pdf&FileName=Investigative%20Photographs%20-%20ERA19LA258-Rel.pdf - Wreckage release (item 8, PDF, 1 page, 948 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13639420&FileExtension=pdf&FileName=720672%20wreckage%20release%20to%20NTSB_Final_Redacted-Rel.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.