ERA14LA402

NTSB accident investigation · Thibault Michael L RV4 · Polk Township, PA · August 21, 2014

Accident · Minor injuriesLimited investigationFinal report
Date
August 21, 2014, 18:50 local (22:50 UTC)
Place
Polk Township, PA
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N62632Thibault Michael L RV4
Defining event
Enroute-cruise: Loss of engine power (total)
Weather
Visual (VMC) · Day
Status
Completed · report November 29, 2016
Report
Approved by Office Director
NTSB office
Eastern Region Aviation
Parties
FAA-FSDO
FAA report
20140821019539A
Case key
89932

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

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 · 1

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Not determinedNot determined › Not determined · Unknown/Not determinedThibault Michael L RV4: 1 caseAll aircraft: 2,247 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

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
Reported as
Thibault Michael L RV4
Category
Airplane, amateur-built
Serial number
1733
Built
1998
Airframe hours
296.5
Engine
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

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
43
Injuries
Minor
Certificate
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

Docket · 4

The files NTSB released with the investigation on August 24, 2016, on NTSB’s docket system: statements, records, photos and specialists’ reports. 3.0 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.

Other investigations on N62632 · 1

Matched to the same aircraft by N-number and date.