# NTSB CEN10LA131: Lacour Long-EZE SR7-1, N97EZ, Falfurrias, TX, March 1, 2010 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: February 28, 2010, 18:45 local (Mar 1, 2010, 00:45 UTC) - Place: Falfurrias, TX - Coordinates: 27.220041, -98.139625 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=27.2200&lon=-98.1396&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: 2 uninjured - Status: Completed, report December 20, 2010 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA Flight Standards District Office - NTSB case key (mKey): 75422 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN10LA131 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/75422/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=75422 - Page: https://openairdocs.org/ntsb/CEN10LA131 ## Probable cause A total loss of engine power due to a failure of the crankshaft behind the No. 3 connecting rod journal for undetermined reasons. ## 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; cases with it: [Lacour Lloyd J JR LONG-EZ, 1 case](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=0569024), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md) - [Propeller system: propeller assembly](https://openairdocs.org/ntsb-findings/01046110): Aircraft › Aircraft propeller/rotor · Design (probable cause); cases with it: [Lacour Lloyd J JR LONG-EZ, 1 case](https://openairdocs.org/ntsb-findings/01046110/cases.md?model=0569024), [All aircraft, 29 cases](https://openairdocs.org/ntsb-findings/01046110/cases.md) - [Maintenance: modification/alteration](https://openairdocs.org/ntsb-findings/02062030): Personnel issues › Task performance · Owner/builder (probable cause); cases with it: [Lacour Lloyd J JR LONG-EZ, 1 case](https://openairdocs.org/ntsb-findings/02062030/cases.md?model=0569024), [All aircraft, 69 cases](https://openairdocs.org/ntsb-findings/02062030/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: [Lacour Lloyd J JR LONG-EZ, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=0569024), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Lacour Lloyd J JR LONG-EZ, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=0569024), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot reported that he was in level cruise flight at 3,500 feet mean sea level when the engine suddenly vibrated then seized. The pilot made a "firm" forced landing on rolling brush and rock-strewn terrain. During the landing roll, the landing gear was sheared off and the canard wing was crushed. Engine disassembly revealed case fretting and main bearing movement. A representative of the engine manufacturer indicated that the failure mode was extremely rare, if not unique. The pilot had installed a Hertzler “Silver Bullet” composite propeller to the extended hub. According to the representative, it was possible that a harmonic vibration could have emanated from the propeller through the extended hub to the crankshaft. However, this propeller had not been tested to determine if there were amplified propeller harmonics to the crankshaft and the investigation was unable to determine that such vibration led to the engine failure. ## Factual narrative On February 28, 2010, approximately 1845 central standard time, a Lacour Long-EZ SR7-1, N97EZ, registered to and operated by the pilot, was substantially damaged when it impacted terrain during a night forced landing after the engine seized in cruise flight near Falfurrias, Texas. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91 without a flight plan. The pilot and passenger on board the airplane were not injured. The cross-country flight originated at San Antonio (SAT), Texas, approximately 1800, and was en route to McAllen (MFE), Texas. The pilot said he was in level cruise flight at 3,500 feet msl when the engine suddenly vibrated then seized. The pilot lowered the nose gear and made a forced landing on rolling brush and rock-strewn terrain. Touchdown was "firm." During the landing roll, the landing gear was sheared off and the canard wing was crushed. On April 23, 2010, the engine was disassembled and inspected at Cutter Aviation in San Antonio, Texas, under the direction of an FAA airworthiness inspector. Although no metallic particles were found in the drained crankcase oil, some were found in the suction oil screen. The oil filter was relatively clean. The vacuum pump’s nylon drive shaft was sheared. Upon removal of the accessory drive case cover, it was discovered that the small drive gear had been thrust approximately 1/8” out of alignment with the other drive gears. Number 4 cylinder and piston showed unusual wear and discoloration. Inspection of the crankshaft revealed it had sheared at the rear of the number three connecting rod journal. A metallurgical examination of the crankshaft was conducted on May 22, 2010, by AADFW Laboratories in Euless Texas. The sample had cracks and three linear indications. There were no hardening indications. “Multiple origin fractures, possible from over stress” were noted. The back sides of the main bearing shells were very shiny, indicative of bearing movement and loose thru-bolt torque. Case fretting was noted in the center main bearing saddle parting surfaces. The report said that the surface origin of the fatigue fracture was in the aft radius of the #3 rod Journal, initiating at approximately 15 degrees after top dead center. “This position is approximately where the maximum power loading would take place during engine operation,” the report said. “Engine timing will have an effect on the exact position of the maximum power loading. Normal engine timing would be 25 degrees BTC. The actual ignition timing is unknown. Advanced timing, such as used with the electronic ignition, is known to produce increased heat, increased power, and increased pre-ignition and detonation probability.” No material defects and no manufacturing issues, such as grinding burn, were found. No assembly issues, such as fillet ride or connecting rod to journal fit, were found. The reportlisted possible causes of the bearing movement and case fretting: (1) maintenance on the ignition system, (2) vibratory stresses from an incompatible combination of propeller and engine, (3) an out-of-balance or out-of-track propeller, and (4) previous damage to the propeller. The report concluded, “This investigative analysis has been unable to determine the root cause of what initiated the fatigue fracture in this crankshaft.” All engine parts were PMA (Parts Manufacturer Approval) certified. PMA is a combined design-production approval, and is required for the production, replacement, or modification of engine parts for sale or installation on type-certificated engine models approved under supplemental type certificates (STC)]. According to Aero Sport Power, this was the first time an O-320-D2A had experienced this type of a failure. It was noted that the pilot had made numerous engine modifications to improve cooling, and utilized extra cylinder head baffles. A non-standard oil pan was installed to accommodate the Long EZ fuselage. The pilot had also installed a Hertzler “Silver Bullet” composite propeller to the extended hub. According to Aero Sport Power, this propeller had not been tested to determine if there were amplified propeller harmonics to the crankshaft. Aero Sport Power recommended a propeller made of wood and heavier than the composite propeller, giving the propulsion system more of a flywheel effect. Aero Sport Power noted that a propeller flies in “dirty air”; that is, it is subject to airflow dynamics generated by the Long-EZ’s canard and wings. Aero Sport Power said it was possible that a harmonic vibration could emanate from the propeller through the extended hub to the crankshaft. FAA Advisory Circular 20-103, dated March 7, 1978, addresses this issue. ## Aircraft - Registration: [N97EZ](https://openairdocs.org/deregistered/N97EZ-2013-05-17), registration cancelled 2013-05-17, S/N 1133, built 1986 (OpenAirDocs) - Reported make and model: Lacour Long-EZE SR7-1 - Registry model: [Lacour Lloyd J JR LONG-EZ](https://openairdocs.org/model/lacour-lloyd-j-jr-long-ez) (registry code 0569024) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 1133 - Airframe hours: 1732 - Engines: Aero Sport Power O-320-D2A 160 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Charles B. McDougal - Registered owner: Charles B. McDougal - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, January 4, 2010, 20 hours before - Departed: SAT, San Antonio, TX - Destination: MFE, McAllen, TX - Airport: BKS, Brooks County ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; injuries: none; commercial, airline transport; airplane ratings: single-engine land, multi-engine sea; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review June 3, 2009; seat: front; flight hours: 8,384 total, 1,337 in this make and model, 7,838 as pilot in command, 50 in the last 90 days, 20 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night/dark - Wind: 90° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 61 °F, dew point 37 °F - Altimeter: 30.10 inHg - Observed at: BKS ## 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 20100228029279A](https://openairdocs.org/incident/20100228029279A), Feb 28, 2010: Lacour Lloy LONG-EZ, Falfurrias, TX, Substantial damage. Enroute from sat to mfe the engine seized and the pilot preformed an off airport landing. ## Docket (6 files) The files NTSB released with the investigation on August 17, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=75422. 26.5 MB in all. - NTSB Form 6120.1-2, Pilot-Operator Aircraft Accident Report (item 1, .PDF, 657 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40335030&FileExtension=.PDF&FileName=NTSB%20Form%206120.1-2,%20Pilot-Operator%20Aircraft%20Accident%20Report-Redacted.PDF - Engine Teardown Notes (item 2, .PDF, 26 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40332264&FileExtension=.PDF&FileName=Engine%20Teardown%20Notes-Master.PDF - Metallurgical Examination Report (item 3, .PDF, 4.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40332450&FileExtension=.PDF&FileName=Metallurgical%20Examination%20Report-Redacted.PDF - Advisory Circular AC 20-103 (item 4, .PDF, 5.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40332269&FileExtension=.PDF&FileName=Advisory%20Circular%20AC%2020-103-Redacted.PDF - Weather Reports and Records (item 5, .PDF, 10 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40332262&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records-Master.PDF - Photos of Engine Teardown Inspection (item 6, .PDF, 15.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40332535&FileExtension=.PDF&FileName=Photos%20of%20Engine%20Teardown%20Inspection-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.