N5985UPiper PA-28-140 · 1970

On February 11, 2015, about 1415 eastern daylight time, a privately owned and operated Piper PA-28-140, N5985U, was substantially damaged when it collided with trees and terrain after takeoff from Air Harbor Airport (W88), Greensboro, North Carolina. The private pilot was fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight, which was conducted under the provisions of 14 Code of Federal Regulations (CFR) Part 91.

On the day of the accident, the pilot had rented the airplane from the owner/operator. A witness observed the pilot start the airplane and taxi to an area near the end of runway 27 where he performed an engine run-up. Two witnesses reported that the takeoff sounded normal; however, they did not hear the airplane continue around the airport traffic pattern. As a result, one of the witnesses drove to the end of runway 27 where he found the wreckage. He approached the airplane and saw that fuel was flowing out of the wing area. He then called 911.

According to Federal Aviation Administration (FAA) records, the pilot held a private pilot certificate with a rating for airplane single-engine land. His most recent FAA third-class medical certificate was issued on January 20, 2014. According to the pilot's records, he had accrued about 359 total hours of flight experience, 63 of which were in the accident airplane make and model.

The accident airplane was a single-engine, unpressurized, low-wing monoplane manufactured in 1970. It was manufactured using conventional metal construction. It was equipped with tricycle landing gear and wing flaps and was powered by a 4-cylinder, 150 horsepower, Lycoming O-320-E2A, air-cooled engine, which drove a metal, two-bladed, fixed-pitch Sensenich propeller.

According to the individual listed on the airplane's registration at the time of the accident, he sold the airplane on August 21, 2013 to the owner/operator. Review of FAA records revealed that, at the time of the accident (approximately 1 1/2 years later), the owner/operator still had not registered the airplane.

When asked about the reason for the sale of the airplane, the previous owner advised that "it had been sitting for several years without flying." A review of the airplane's maintenance records indicated that the last annual inspection performed before the sale, occurred on January 3, 2008, at 3,690.9 total hours of operation. The first annual inspection performed after the sale occurred on January 1, 2014, at 3,709.4 total hours of operation.

The airplane's most recent annual inspection was completed on January 6, 2015. At the time of the inspection, the airplane had accrued 3,787.86 total hours of operation, and the engine had accrued 1,466.86 hours since major overhaul. In addition, the airplane had been operated about 11 hours since the inspection. Review of the rental sheet for the airplane indicated that the engine run for the annual inspection did not occur until January 21, 2015, and was 6 minutes (0.1 hour) in duration. Further review of maintenance records indicated that, at the time of the accident, the transponder inspection was out of date, and FAA Airworthiness Directive (AD) 2010-15-10, which required inspection of the control wheel shafts, had not been accomplished.

The 1354 recorded weather at Piedmont Triad International Airport (GSO), Greensboro, North Carolina, located 8 nautical miles southwest of the accident site, included: calm winds, 10 statute miles visibility, few clouds at 15,000 ft above ground level, temperature 9°C, dew point -1°C, and an altimeter setting of 29.96 inches of mercury.

The accident airplane was a single-engine, unpressurized, low-wing monoplane manufactured in 1970. It was manufactured using conventional metal construction. It was equipped with tricycle landing gear and wing flaps and was powered by a 4-cylinder, 150 horsepower, Lycoming O-320-E2A, air-cooled engine, which drove a metal, two-bladed, fixed-pitch Sensenich propeller.

According to the individual listed on the airplane's registration at the time of the accident, he sold the airplane on August 21, 2013 to the owner/operator. Review of FAA records revealed that, at the time of the accident (approximately 1 1/2 years later), the owner/operator still had not registered the airplane.

When asked about the reason for the sale of the airplane, the previous owner advised that "it had been sitting for several years without flying." A review of the airplane's maintenance records indicated that the last annual inspection performed before the sale, occurred on January 3, 2008, at 3,690.9 total hours of operation. The first annual inspection performed after the sale occurred on January 1, 2014, at 3,709.4 total hours of operation.

The airplane's most recent annual inspection was completed on January 6, 2015. At the time of the inspection, the airplane had accrued 3,787.86 total hours of operation, and the engine had accrued 1,466.86 hours since major overhaul. In addition, the airplane had been operated about 11 hours since the inspection. Review of the rental sheet for the airplane indicated that the engine run for the annual inspection did not occur until January 21, 2015, and was 6 minutes (0.1 hour) in duration. Further review of maintenance records indicated that, at the time of the accident, the transponder inspection was out of date, and FAA Airworthiness Directive (AD) 2010-15-10, which required inspection of the control wheel shafts, had not been accomplished.

Examination of the accident site revealed that, after takeoff from runway 27, the airplane turned left, descended, and then struck approximately 65 foot high trees, about 400 feet from the end of the runway. The airplane first made contact with the trees about 45 ft above ground level, then dropped to the forest floor, coming to rest on its left side wedged between two trees on a magnetic heading of 192° at an elevation of approximately 769 feet msl.

The fuselage exhibited multiple areas of crush and compression damage, and the aft fuselage had been bent about 45° to the left during the impact sequence. The cabin was mostly intact. Examination of the restraint system revealed that the airplane had been equipped with lap belts but was not equipped with shoulder harnesses.

The left wing exhibited crush and compression damage on the leading edges and compression damage at the inboard trailing edge. It remained intact, with the exception of an approximate 4-ft long outboard section that had been separated from the left wing during the impact with trees.

The right wing was almost completely separated from the fuselage at the wing root, and it exhibited impact damage in several places, including a large depressed area at approximately mid-span, where the wing skin had been crushed aft to the wing spar.

The rudder and stabilator remained attached to their mounting points and moved freely. Internal examination of the rudder revealed the presence of wasp nests.

The stall warning vane was in place and operated normally when checked with a volt/ohm meter.

Examination of the instrument panel and flight controls revealed that the throttle was in the full power position, the mixture control was full rich, and the carburetor heat was off. The fuel primer was in and locked. The auxiliary electric fuel pump was "ON." The airspeed indicator needle indicated about 66 knots. The tachometer indicated about 1,100 rpm. The flap handle was in the flaps-retracted position and flight control continuity was established from the ailerons, stabilator, and rudder to the cockpit controls.

Examination of the propeller revealed that the propeller spinner exhibited crush damage on the tip. One side of the spinner and the propeller remained partially attached to the crankshaft flange. The flange was bent and three propeller bolts were broken. One propeller blade was bent aft about 10° about mid-span. The other propeller blade was bent aft about 30° about mid-span. Its tip was bent forward about 10°. There was no evidence of leading edge gouging or chordwise scratching on either blade.

The engine remained attached to the firewall at its mount. The engine was removed from the firewall, suspended from a lift, and partially disassembled to facilitate examination. The drivetrain was rotated and continuity from the crankshaft to the rear gears and valve train was confirmed. Compression and suction were observed on all four cylinders. The interiors of the cylinders were examined using a lighted borescope and no anomalies were noted. Both magnetos produced spark when rotated. The spark plugs appeared normal with the exception of the No. 2 cylinder's bottom spark plug, which was impact-damaged. Oil was present in the engine, and both the oil suction screen and oil filter were clean absent of debris.

The carburetor remained attached to the engine. It was removed and partially disassembled, and about 2 teaspoons of fuel were observed in the float bowl. The carburetor fuel inlet screen was absent of debris and the carburetor internal components were undamaged. The engine-driven fuel pump remained attached to the engine and was impact-damaged. The pump was removed and partially disassembled. A small amount of fuel drained from the pump when it was tilted. No damage to the rubber pump diaphragms or check valves was noted.

The fuel strainer and electric fuel pump were removed and disassembled; both were devoid of fuel. The strainer and pump fuel screens contained no debris.

The fuel selector valve handle was found in the right tank position. The fuel selector valve was then removed from the airplane. With the handle in the right tank position, air was applied to the selector valve but would not pass through the valve. Subsequent attempts to manipulate the selector valve revealed that it was stiff to rotate, and positive engagements of the detents could not consistently be obtained. Further attempts to flow air through the valve produced intermittent results. Disassembly of the fuel selector valve revealed rotational scoring in the valve body and on the plug cock, which also displayed discoloration and worn detents.

Information Provided by the Chief Mechanic

The owner/operator's chief mechanic stated that he had assisted the owner in putting the airplane back into service after the owner purchased it. They had replaced all the hoses in the engine compartment, but did not do any work aft of the firewall with the exception of replacing the battery.

The chief mechanic also stated that he performed the airplane's last two annual inspections. He advised that entries for the last annual inspection were incorrect, and the annual was actually completed on January 21, 2015. He used Piper guidelines as well as 14 CFR Part 43 during the inspections of the airplane. The fuel selector was "stiff" to turn, but he thought it was not any tighter than any other older Piper he had worked on, and it seemed to work fine.

According to the chief mechanic, the owner/operator and the mechanic's helper also assisted with the annual inspection. He and the mechanic's helper had worked separate from the owner/operator and had not performed any work on the fuel selector. He and the mechanic's helper would always "check behind each other." He stated that had performed AD 2010-15-10 regarding inspection of the control wheel shafts, but had not entered it into the maintenance records. He stated that he was not in the airplane when the mechanic's helper performed the engine run-up following completion of the annual inspection, so he did not know if he had "exercised the fuel valve in the airplane."

The chief mechanic stated that he did not feel that anything was unairworthy with the airplane, and he was not aware that the owner had not registered the airplane after purchasing it.

Information Provided by the Mechanic's Helper

The mechanic's helper stated that his work was supervised by the owner/operator or the chief mechanic. He had performed most of the annual inspection as well as the engine run, which he performed alone. He was unaware that the engine run was part of the annual inspection and that a certificated mechanic with an inspection authorization was required to perform the engine run. He remembered that he had function-tested the fuel selector as part of the annual inspection and that he cycled it on and off and made sure it had "feel." He also pressurized it with the electric fuel pump and did not notice any fuel leaks. He was unaware that he was required to list his name in the maintenance records when performing work as a mechanic's helper.

He had started working for the owner/operator 8 years before the accident and had performed some of the work on the airplane to bring it back into service. He remembered that they had changed all the hoses forward of the firewall after the purchase, but they had not performed any work on the fuel selector, fuel lines, or vent lines, other than making sure that the vent lines were clear. He was aware that there were numerous discrepancies in the maintenance records for the airplane, including an undocumented oil change. He also knew that the airplane had been purchased by the owner in 2013, but was still registered to the previous owner.

Information Provided by the Owner/Operator

The owner/operator stated that, during the annual inspection, he never felt any "galling, binding, or anything else" when he checked the fuel selector valve. The mechanic's helper then checked it, then he checked the fuel strainer and they ran the electric pump. He never noticed any fuel staining.

He stated that, "there were no complaints or squawks prior to the accident." He also stated that after he purchased the airplane, and, before returning it to service, they "replaced all rubber lines firewall forward."

On his most recent FAA medical certification application, the 74-year-old pilot reported that he had glaucoma treated with timolol, prostatic hypertrophy treated with alfuzosin, and was using the cholesterol-lowering medication atorvastatin.

Autopsy

An autopsy was performed on the pilot by the North Carolina Department of Health and Human Services Office of the Chief Medical Examiner. The cause of death was multiple crushing blunt force injuries.

The autopsy revealed evidence of atherosclerotic cardiovascular disease. The pilot's heart weighed 450 grams (average heart weight for a 172-lb man is 345 grams, with a range from 261-455 grams) with concentric left ventricular myocardial hypertrophy. The coronary arteries exhibited up to 70%, 50%, and 60% luminal stenosis of the left anterior descending, circumflex, and right coronary arteries, respectively. The myocardium showed no evidence of scarring.

Toxicological Testing

Toxicological testing was conducted at the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. Toxicology identified alfuzosin and timolol; both had been reported during the pilot's FAA medical examinations. Additionally, citalopram and its metabolite, N-Desmethylcitalopram, were detected; this medication was not reported to the FAA. FAA toxicological testing does not distinguish between citalopram and the isomer escitalopram.

Both citalopram and escitalopram are prescription antidepressants marketed with the names Celexa and Lexapro, respectively. The medications carry the warning; "May impair mental and/or physical ability required for the performance of potentially hazardous tasks (e.g., driving, operating heavy machinery)."

According to the FAA's Guide for Aviation Medical Examiners, pilots treated for depression with citalopram or escitalopram may be considered for a special issuance medical certificate if the pilot has been clinically stable, as well as on a stable dose of medication without any aeromedically significant side effects and/or an increase in symptoms.

According to his family, the pilot was in good health, but had a history of anxiety that was well-managed with escitalopram without noted side effects.

Fuel System Description and Review

The airplane was equipped with two 25-gallon fuel tanks, which were secured to the leading edge structure of each wing by screws and nut plates. Each tank had an individual fuel drain at the bottom inboard corner, which was used to check for water or sediment. From the outlet of each tank, fuel lines were routed through the wings to the fuel selector valve located on the left side panel forward of the pilot's seat. From the fuel selector valve, a line led to the fuel strainer bowl, which was mounted on the front of the engine firewall. The fuel line then routed from the strainer bowl to the electric fuel pump, engine driven fuel pump, and carburetor.

Examination of the fuel selector control revealed that it was likely original to the airplane. It had four selectable positions: LEFT TANK, RIGHT TANK, OFF, and OFF, indicating that it had not been modified per Piper Service Bulletin No. 840, issued in 1986, or per Piper Service Bulletin No. 840A, which superseded the previous bulletin and was issued in 2013. The modification would have reconfigured the fuel selector so it had a spring-loaded metal stop and only three selectable positions: L TANK, R TANK, and FUEL OFF. Piper Aircraft considered that compliance with these service bulletins was mandatory, which was clearly stated on the service bulletin, to reduce the possibility of pilot mismanagement of the fuel system through inadvertent selection of the "OFF" position, which could result in power interruption or engine stoppage.

The electric fuel pump was provided in case the engine-driven fuel pump failed; the electric fuel pump was required to be on for takeoff, landing, and when switching tanks. Examination of the pump indicated that it was functional, and the electric fuel pump switch was found in the "ON" position following the accident.

The fuel strainer, which was equipped with a quick drain, was located on the lower left front of the engine firewall and was accessible outside of the nose section. A witness, who saw the airplane taxiing before the accident, observed what he believed was possibly fuel "atomizing" in front of the left wing of the airplane. He advised that it appeared to be coming from the front of the wing root area near the firewall (near where the fuel strainer was located) and dispersing aft over the wing. Examination of the fuel strainer had revealed though, that the quick drain was closed. During further examination of the fuel system for a source of the fuel the witness observed, it was discovered that, fuel staining was seen inside the wings, and the rubber fuel tank vent tube couplers were found age-hardened, split, and leaking.

Fuel Valve Inspection Guidance

According to the Piper Cherokee Service Manual, the operation of the fuel selector valve was required to be confirmed during inspections. The manual advised that, when the fuel selector handle was not in a positive selector detent position, more than one fuel port would be open at the same time. The manual stated, "It should be ascertained that the fuel selector is positioned in a detent, which can be easily felt when moving the handle through its various positions."

According to FAA Advisory Circular (AC) 43.13-1B, Acceptable Methods, Techniques, and Practices – Aircraft Inspection and Repair, when inspecting fuel crossfeed, firewall shutoff, and tank selector valves, these valves must be inspected for leakage and proper operation. In the case of selector valves, this means the operation of each handle or control needs to be checked to see that it indicates the actual position of the selector valve to the placard location. Movement of the selector handle should be smooth and free of binding, and stops and detents should exhibit positive action and smooth operational feel, as worn or missing detents and stops could cause unreliable positioning of the fuel selector valve. Inaccurate positioning of fuel selector valves could also be caused by worn mechanical linkages between the selector handle and the valve unit. Universal joints, pins, gears, splines, cams, levers, etc., should be checked for wear and excessive clearance, which prevent the valve from positioning accurately or from obtaining fully "off" and "on" positions. An improper fuel valve position setting could seriously reduce engine power by restricting the available fuel flow.

High Resolution Photography of Valve Body and Plug Cock

Comparison of the fuel selector valve to an exemplar valve removed from another airplane with about 2,206 total hours of operation revealed that the exemplar valve rotated smoothly, and the detents could be felt positively when the valve was selected to each position.

High resolution photography of the fuel selector valve revealed the presence of staining, corrosion, and debris, and the plug cock had debris embedded in its surface. None of the noted anomalies observed in the accident airplane's fuel selector valve were observed with the same severity in the exemplar valve.

Materials Identification and Spectroscopy

Positive material identification was used to determine the materials composition of the valve body, valve stem, and position washer.

Spectroscopy of the debris particles found in the valve body and embedded in the plug cock, revealed that the debris particles contained elements like the ones that made up the composition of the valve body, valve shaft, and position washer.