Aviation Accident Summaries

Aviation Accident Summary SEA05LA089

Kennewick, WA, USA

Aircraft #1

N8023R

Aeronca 0-58B

Analysis

The airplane lost engine power and collided with terrain during the forced landing. According to the pilot, after purchasing the airplane and being briefed on the fuel system, he departed on the first leg of the transcontinental flight. The fuel system was comprised of a 10 gallon overhead center tank which fed directly into a 2 gallon header tank. Also incorporated into the system was a 10 gallon right wing tank whose fuel line teed into the center tank's line. A shutoff valve was incorporated in the "T" which would allow both tanks to feed the header tank simultaneously. Procedures called to use half of the fuel in the center tank before opening a shutoff valve. On the first leg of the flight the pilot flew 45 minutes before opening the shutoff valve. After landing approximately 35 minutes later he instructed the fueling attendant to fill both the center and wing tanks so he could judge the consumption of fuel from each tank. After fueling was completed the attendant advised the pilot that he had put 8.5 gallons of fuel in the center tank, and that the wing tank was full. The pilot commented that this wasn't right, but voiced no further concerns and departed on the next leg of the flight, a distance of about 90 nautical miles. About one hour into the flight the pilot opened the wing tank shut off valve, and when he was about an hour and 30 or 40 minutes into the flight while descending he encountered a "surge" in the engine. The pilot added carburetor heat with no success, and when the engine quit completely he elected to land in a wheat field. After touching down and impacting a plow rut the airplane nosed over and came to rest on its back in an inverted position, resulting in substantial damage to the airplane's vertical stabilizer. The pilot stated that he felt the reason for the engine failure was due to fuel exhaustion as a result of fuel being vented from the wing tank, which resulted in fuel from the center tank being sucked into and replacing the fuel in the wing tank. Further examination by the FAA failed to reveal any fuel present at the accident site. It was also noted that the installation of the wing tank was a modification of the airplane, which required a Supplemental Type Certificate (STC). A search by the FAA failed to reveal an STC for this aircraft relative to the right wing tank installation. The inspector also supervised an engine test run with no anomalies noted. The reason for the reported loss of engine power could not be determined.

Factual Information

On April 27, 2005, at 1742 Pacific daylight time, an Aeronca 0-58B, N8023R, single-engine airplane sustained substantial damage following a loss of engine power and forced landing approximately 20 nautical miles southwest of Kennewick, Washington. The pilot, sole occupant of the airplane, was not injured. Visual meteorological conditions prevailed for the cross-country flight, which was operated in accordance with 14 CFR Part 91, and a flight plan was not filed. The flight departed the Columbia Gorge Regional/The Dalles Municipal Airport (DLS), The Dalles, Oregon, at approximately 1530, with its destination being the Vista Field Airport (S98), Kennewick, Washington. In a telephone interview with the NTSB investigator-in-charge (IIC), and according the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), the pilot reported that he had just purchased the airplane and was in the process of ferrying it cross-country from the Aurora State Airport (UAO), Aurora, Oregon, to Plantation, Georgia. The pilot stated that prior to his departure the previous owner went over engine operations and the fuel system. The pilot reported that the aircraft held about 22 gallons of fuel; 10 gallons in the center tank, 10 gallons in the right wing tank, and 2 gallons in a hopper tank, which was located behind the firewall. The pilot stated that the fuel in the center tank drains through a "T" valve into the 2-gallon hopper tank, [and] the right [wing] tank also drains through the same "T" valve to the hopper tank, but is equipped with a shutoff valve. The pilot stated that when both the center and wing tanks were full you should shut off the wing tank and burn out of the center tank [until] you have burned about 5 gallons or about one-half way on the quantity gauge. The pilot further stated that at this point you can open the [shutoff] valve for the wing tank and both tanks should drain into the 2-gallon hopper tank. The pilot stated, "This is the procedure I followed." The pilot reported that on the first leg of the flight from UAO to the Columbia Gorge Regional/The Dalles Municipal Airport (DLS), a distance of about 80 nautical miles, the flight took 1 hour and 20 minutes. The pilot stated that when about 45 minutes en route the center tank indicated about one-half, at which time he opened the wing tank shutoff valve. After landing at DLS the pilot instructed the fueling attendant to fill both the center and wing tanks and note the quantity each tank took so he could gauge the consumption of fuel from each tank. The pilot reported that after eating lunch the fueling attendant told him the plane took 8.5 gallons in the center tank and the wing tank was full. In a telephone interview with the IIC, the fueling attendant reported that after advising the pilot that he filled the center tank and that the wing tank was full, "...the pilot commented that that wasn't right, that the way it was supposed to operate fuel should have drained out of the wing tank too." The fueling attendant stated the pilot didn't voice any other concerns about the issue. The pilot reported in his statement, "I thought this was rather odd and decided to stop at S98 to check fuel consumption again, since the distance was only about 90 NM." The pilot reported that when he was about one hour en route at 2,500 feet mean sea level on the second leg of the flight he opened the wing tank shutoff valve, and approximately 1 hour and 30 to 40 minutes en route to S98 while descending he encountered a "surge" in the engine. The pilot stated that the first thing that came to his mind was carburetor ice, but applying carburetor heat did not result in any appreciable change in the engine operation. The pilot further stated that when the engine operation became intermittent he elected to land on a road, but when the engine completely quit he decided to land in a wheat field. The pilot reported that after touching down the main gear impacted a plow rut and slowly nosed over on its back. The pilot stated that he felt the reason for the engine quitting was due to fuel exhaustion as a result of fuel venting from the right wing tank. A Federal Aviation Administration (FAA) airworthiness inspector, who traveled to the accident site, reported substantial damage to the vertical stabilizer and rudder. There was also damage to the propeller, right wing strut, and nose cowling. The inspector also reported that there was no fuel present in the header tank, the gascolator contained only a few drops of fuel, and there was no fuel present in the wing tank or center tank. The inspector also informed the IIC that upon a review of the maintenance records, it was revealed that the installation of the wing tank was a modification of the airplane, which required a Supplemental Type Certificate. The inspector further reported that since no Supplemental Type Certificate existed for this installation, it was an illegal modification of the aircraft. The inspector reported that both the center tank and the right wing tank were equipped with vented fuel caps, with the vent tube of each cap exiting the cap vertically, and then oriented/bent 90 degrees forward and parallel to the longitudinal axis of the airplane. The fueling attendant who fueled the airplane at DLS remembered securing the fuel caps after fueling, however, he could not remember in which direction the vent tubes were oriented. The engine was later test run under the supervision of the FAA inspector, with no anomalies noted. The reason for the reported loss of engine power could not be determined.

Probable Cause and Findings

Loss of engine power for undetermined reasons, which resulted in a forced landing and subsequent nose over. A factor was the unsuitable terrain.

 

Source: NTSB Aviation Accident Database

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