# NTSB ERA14LA402: Thibault Michael L RV4, N62632, Polk Township, PA, August 21, 2014 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: August 21, 2014, 18:50 local (22:50 UTC) - Place: Polk Township, PA - Coordinates: 40.919998, -75.442779 - Nearby events: https://openairdocs.org/map.md?lat=40.9200&lon=-75.4428&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: Minor injuries - Injuries: 1 minor - Status: Completed, report November 29, 2016 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA-FSDO - NTSB case key (mKey): 89932 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA14LA402 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/89932/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=89932 - Page: https://openairdocs.org/ntsb/ERA14LA402 ## Probable cause A total loss of engine power due to fuel starvation for reasons that could not be determined because postaccident examination of the engine revealed no anomalies. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Thibault Michael L RV4, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=05605M3), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/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: [Thibault Michael L RV4, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=05605M3), [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: [Thibault Michael L RV4, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05605M3), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-flare/touchdown: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Thibault Michael L RV4, 1 case](https://openairdocs.org/ntsb-events/096/sequence.md?model=05605M3), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The airline transport pilot reported that he visually inspected the fuel tanks before takeoff and that each tank was "just less than half" full. After takeoff for the local personal flight, the pilot climbed the airplane to 2,000 ft mean sea level, and, upon leveling off, switched the fuel selector to the left wing tank. Shortly thereafter, the engine experienced a total loss of power, and the pilot conducted a forced landing to a soybean field. During the landing, the airplane nosed over and then came to rest inverted, which resulted in substantial damage to the firewall and right wing. Examination of the engine and fuel system revealed no anomalies. The engine was turned by hand at the propeller, and compression was confirmed to all cylinders using the thumb method. The left magneto produced spark when rotated. A total of 2 ounces of fuel was recovered from both of the fuel tank sump drains. Fuel staining was observed on the top of the left wing, consistent with fuel leaking from the tank while the airplane was inverted following the accident. However, no fuel was present in the fuel hose from the engine-driven fuel pump to the carburetor inlet; therefore, it is likely that the engine was not getting fuel. Neither the quantity of fuel present in the tank before the accident nor the reason there was no fuel in the fuel hose could be determined. ## Factual narrative On August 21, 2014, about 1850 eastern daylight time, an experimental amateur-built RV-4, N62632, was substantially damaged during a forced landing following a total loss of engine power near Polk Township, Pennsylvania. The commercial pilot sustained minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight, which departed Beltzville Airport (14N), Lehighton, Pennsylvania, about 1835. The personal flight was operated under the provisions of Title 14 Code of Federal Regulations Part 91. The pilot reported to a Federal Aviation Administration (FAA) inspector that he conducted a preflight inspection of the airplane, and estimated that each of the two fuel tanks were "just less than half" full, which he stated would provide about 1.5 hours of flight time. After takeoff, the pilot climbed the airplane to an altitude of 2,000 ft mean sea level (msl), and upon leveling off, switched the fuel selector to the left wing tank. Shortly thereafter, the engine "sputtered and quit." The pilot turned on the fuel pump, switched the fuel selector to the "both" position, then the right fuel tank; however, engine power was not restored. The pilot subsequently conducted a forced landing to a soybean field. During the landing, the airplane nosed over and came to rest inverted, resulting in substantial damage to the engine firewall and right wing. Examination of the engine and fuel system revealed no anomalies. The engine was turned by hand at the propeller and compression was confirmed to all cylinders using the thumb method. The left magneto produced spark when rotated. Throttle cable movement was inhibited by the engine mount deformation, carburetor heat control was operative but stiff, and the mixture control operated freely. Approximately 2 ounces of fuel were recovered from both fuel tank sump drains. No fuel was present in the fuel hose from the engine driven fuel pump to the carburetor inlet. Fuel staining was observed on the top of the left wing, with no evidence of fuel staining on the top of the right wing. The carburetor throat was clear of obstructions and foreign matter; the secondary venturi, nozzle, and accelerator pump spout were intact and secure. The carburetor fuel inlet finger screen was clean. The airplane was manufactured in 1998, and was equipped with a Lycoming O-320, 150-hp reciprocating engine. The airplane's most recent condition inspection was completed on June 1, 2014, at a total aircraft time of 296.5 hours. The pilot held a commercial pilot certificate with ratings for airplane single engine land and glider, a flight instructor certificate with ratings for airplane single-engine and glider, and an airline transport pilot certificate with a rating for airplane multiengine land. He reported 2,800 total hours of flight experience, of which 23 hours were in the accident airplane make and model. The 1853 automated weather observation at Pocono Mountains Municipal Airport (MPO), locatedabout 13 nautical miles north of the accident site, reported wind from 200 degrees at 6 knots, few clouds at 1,300 ft, broken clouds at 3,100 feet, temperature 22 degrees C, dew point 19 degrees C, and an altimeter setting of 30.05 inches of mercury. Review of a carburetor icing probability chart indicated the potential for serious icing at glide power. ## Aircraft - Registration: [N62632](https://openairdocs.org/aircraft/N62632), registered now, S/N 1733, built 1998 (OpenAirDocs) - Reported make and model: THIBAULT MICHAEL L RV4 - Registry model: [Thibault Michael L RV4](https://openairdocs.org/model/thibault-michael-l-rv4) (registry code 05605M3) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 1733 - Year built: 1998 - Airframe hours: 296.5 - Engines: LYCOMING O-320 E2D 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, June 1, 2014 - Departed: 14N, LEHIGHTON, PA - Destination: 14N, LEHIGHTON, PA - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; injuries: minor; airline transport; airplane ratings: single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review August 1, 2013; seat: front; restraint: 4-point; flight hours: 2,800 total, 23 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 6 knots - Visibility: 7 statute miles - Lowest ceiling: 3,100 ft broken - Temperature: 72 °F, dew point 66 °F - Altimeter: 30.04 inHg - Observed at: KMPO, 13 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 20140821019539A](https://openairdocs.org/incident/20140821019539A), Aug 21, 2014: Thibault Michael L RV4, Gilbert, PA, Substantial damage. Pilot was at cruise when he switched fuel tanks. Engine sputtered and failed. Pilot switched tanks attempted restart. Unable to regain engine power pilot made… ## Other investigations on N62632 (1) 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 ATL99LA030](https://openairdocs.org/ntsb/ATL99LA030), Dec 6, 1998: Michael L. Thibault RV-4 (N62632), Okeechobee, FL, substantial damage. Probable cause: The pilot's failure to use carburetor heat that resulted in the total loss of engine power. Factors were conditions favorable for the formation of carburetor ice. ## Docket (4 files) The files NTSB released with the investigation on August 24, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=89932. 3.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40443673&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - FAA Inspector's Statement (item 2, .PDF, 194 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40443674&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Statement-Master.PDF - Carburetor Icing Probability Chart (item 3, .PDF, 227 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40443675&FileExtension=.PDF&FileName=Carburetor%20Icing%20Probability%20Chart-Master.PDF - Accident Photos (Courtesy of FAA) (item 4, .PDF, 3 photos, 973 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40443676&FileExtension=.PDF&FileName=Accident%20Photos%20(Courtesy%20of%20FAA)-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.