NTSB Factual Report

HISTORY OF FLIGHT

On January 25, 2017, about 1730 central standard time, a Cessna 172 airplane, N5639A, impacted trees and terrain during a forced landing near Jay, Oklahoma, following an in-flight loss of engine power. The private pilot was fatally injured. The airplane was substantially damaged. The airplane was owned by Mexico Medical Missions and was operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Day visual meteorological conditions prevailed at the time of the accident and no flight plan was filed. The flight departed from a private airstrip near Jay, Oklahoma, and was destined for the Grove Municipal Airport (GMJ), Grove, Oklahoma.

According to fueling records from GMJ, the pilot purchased 9.56 gallons of 100 low lead aviation gasoline (avgas) at 1019 on January 24, 2017.

According to a witness at the departure airstrip, the pilot intended to fly the airplane to GMJ. He saw the pilot service both of the airplane's fuel tanks with fuel from fuel cans. He saw the pilot taxi up and down the runway multiple times. The airplane subsequently departed and the witness drove to GMJ to pick up the pilot. When the pilot did not arrive, he reported the airplane as missing. The emergency locator transmitter signal was detected and a helicopter pilot spotted the airplane in a field near a tree line about .75 nautical miles east of the departure airstrip.

PERSONNEL INFORMATION

The 61-year-old pilot held a Federal Aviation Administration (FAA) private pilot certificate with an airplane single engine land rating. He also held an FAA third-class medical certificate that was issued on August 23, 2016, with no limitations. The pilot reported on his application for his medical certificate that he accumulated 450 hours of total flight time with 1 hour in the 6 months preceding his medical.

AIRCRAFT INFORMATION

The airplane, serial number 28239, was an externally braced high-wing, propeller-driven, fixed landing gear, semi-monocoque design, four-seat airplane manufactured in 1956. A 145-horsepower Continental O-300 engine, marked with serial number 11594-D-6-B, drove a two-bladed, all-metal, fixed pitch, McCauley model 1A170/DM765 propeller, with serial number 62885. Airplane logbooks revealed that the last recorded annual inspection was completed on July 3, 2008. An endorsement for that inspection showed that the airplane tachometer indicated 2,817.4 hours and that the airplane had accumulated 5,739.4 hours of total time.

The airplane flight manual found in the airplane, in part, stated:

FUEL SYSTEM

Fuel is supplied to the engine from two 21 gallon aluminum tanks, (of which 18.5 gallons in each tank are useable in all flight conditions) one located in each wing. From these tanks fuel flows by means of gravity through a fuel selector and fuel strainer to the engine carburetor.

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Fuel Selector Valve. A rotary type fuel selector valve is located at the aft end of the cabin floor tunnel between the front seats. The valve has four positions labeled "BOTH OFF", "LEFT TANK", "RIGHT TANK", and "BOTH ON". The "BOTH OFF" position seals both wing tanks off from the rest of the fuel system and allows no fuel to pass beyond the selector valve. The "LEFT TANK" position allows fuel to flow from the left wing tank to the engine. The "RIGHT TANK" position permits fuel to flow from the right wing tank to the engine. The "BOTH ON" position provides fuel flow from both tanks simultaneously to provide maximum safety. Important – The fuel valve handle indicates the setting of the valve by its position above the valve dial.

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Fuel Quantity Indicators. A direct reading, dampened, float-type fuel quantity indicator is mounted in each tank at the wing root inside the cabin. Each gage indicates the amount of fuel remaining in its respective tank. A red arc is painted on the face of each indicator to warn the pilot that the respective fuel tank is almost empty. Do not take off if the pointer is in the red arc.

The fuel selector handle connects to the fuel selector valve and is retained in place by means of a securing pin.

METEOROLOGICAL INFORMATION

At 1735, the recorded weather at GMJ was wind 290° at 7 knots, visibility 10 statute miles, sky condition clear, temperature 6° C, dew point -2° C, and altimeter 29.96 inches of mercury.

WRECKAGE AND IMPACT INFORMATION

The airplane was found inverted on about a 40° heading about 7 miles and 214° from GMJ in an open field with hay rolls scattered throughout the field. The airplane came to rest near a tree line that bounded the western edge of the field. The first found tree with a broken branch was observed about 125 feet and 267° from the wreckage. Broken and separated branches with signs of recent breaks were observed aloft in trees and on the ground from that first found tree towards the wreckage. Sections of clear plastic consistent with the landing light lens and chips of paint consistent with the color of the airplane were found along that same path to the wreckage. The left wing had a semicircular depression in its leading edge between its landing light and its wing tip. The size of a separated tree branch was consistent with the size of the shape of the semicircular depression.

All of the airplane's control surfaces remained attached to the airplane. Flight control cables were traced and fight control cable continuity was established. No cable separations were observed. The elevator trim control cable was continuous from the trim wheel chain to the trim actuator and its trim tab arm was attached to the trim tab. The flap system's control cables were continuous from its flap actuator bar to the flaps' bellcranks. The bellcranks' push/pull rods were connected to their respective flap. The extent of flap deployment could not be determined due to post impact damage. The elevator trim was about 1.3 inches, which equates to a position of about 5° tab trailing edge down. The elevator trim indicator was observed in the take-off range.

The engine was found displaced rearward into the firewall. The propeller blades did not exhibit any chordwise abrasions or leading edge nicks. One propeller blade was bent rearward. The carburetor was found separated from its mounting flange.

The fuel system was found intact except for a separated line near the left fuel tank. About 6 gallons of a blue-colored liquid consistent with the smell and color of avgas was recovered from the right fuel tank. About 2 gallons of liquid consistent with avgas was recovered from the left fuel tank. Some liquid consistent with avgas was found in the carburetor bowl and in the firewall-mounted strainer bowl. All found and recovered liquid samples were tested for water contamination using water paste and no water contamination indication was observed. The fuel valve selector handle was found in the right tank position. No securing pin was installed in the selector handle. Pressurized air was applied to the main fuel line at the firewall and air discharged from the left tank's fuel line. Both fuel tank caps were removed. The right tank cap was a vented cap. A vacuum was applied to the cap's vent and no obstructions were noted. The left tank cap was a non-vented cap. The left tank vent was observed and no obstruction was present on its intake screen. The airplane was righted and the fuel quantity indications changed as fuel migrated within the fuel tanks when the wings were rocked by hand.

The tachometer indicated 2,848.03 hours and the Hobbs meter indicated 1,137.8 hours. The ignition switch key was broken and a section of key was retained within the switch. The ignition switch was found in the "both" position. The master switch was found in the "on" position. The primer was found in a forward position. However, it was not in its locked position. The mixture and throttle were in their forward positions. The carburetor heat was found in its off position.

The engine and separated carburetor were shipped to the engine manufacturer for a detailed examination.

MEDICAL AND PATHOLOGICAL INFORMATION

The State of Oklahoma, Office of the Chief Medical Examiner conducted an autopsy on the pilot. The autopsy listed multiple blunt force injuries as the cause of death and accident as the manner of death.

The FAA Civil Aerospace Medical Institute conducted toxicology testing of specimens from the pilot. The report was negative for all tests performed.

SURVIVAL ASPECTS

The Cessna 172 did not have shoulder harnesses installed and was not required to have them installed at the time it was certified.

TESTS AND RESEARCH

On March 7, 2016, the engine was examined at Continental Motors in Mobile, Alabama. The main portion of the carburetor was in the shipping crate with the engine. The separated sections of the carburetor were not shipped with the engine. However, they were located at the recovery company's facilities and were subsequently shipped for the examination.

The engine was removed from the shipping crate and prepared for examination. Both rear engine mounts were damaged and replaced with exemplar mounts. Both sparkplug harnesses were damaged and replaced with exemplar harnesses. The oil drain was damaged and an exemplar plug was installed. The carburetor was damaged and an exemplar carburetor was mounted to the intake. Magneto timing and cylinder compression were checked. The No. 4 rocker cover was damaged and an exemplar cover was installed. An adapter plate and test club were mounted on the propeller flange. The engine was mounted in an engine run cell and was test run with the exemplar carburetor, and the engine was operational when it produced rated power.

The original carburetor body and bowl cover assembly mounting flange was separated into sections and the throttle shaft and its throttle valve was liberated from the assembly. Due to the extent of damage to the original body and bowl cover assembly, an exemplar assembly was used with the original carburetor's mixture metering valve assembly, float valve and seat assembly, and float bracket. The exemplar cover with original components was mated to the original carburetor body and bowl assembly and this carburetor was mounted to the intake and the engine was test run a second time. The engine was operational when it produced rated power and responded to rapid throttle accelerations/decelerations throughout its full range using the original carburetor with exemplar body and bowl cover assembly.

Both removed sparkplug harnesses were mounted to a test bench. Spark was observed at the ends of all leads when the test bench equipment was operated.

ADDITIONAL DATA/INFORMATION

FAA Advisory Circular 91-65, Use of Shoulder Harness in Passenger Seats, in part, stated, "The [National Transportation Safety Board] found that 20 percent of the fatally injured occupants in these accidents could have survived with shoulder harnesses (assuming the seat belt fastened) and 88 percent of the seriously injured could have had significantly less severe injuries with the use of shoulder harnesses. Energy absorbing seats could have benefited 34 percent of the seriously injuries. The safety board concluded that shoulder harness use is the most effective way of reducing fatalities and serious injuries in general aviation accidents."

Additionally, the FAA issued policy statement, ACE-00-23.561-01. The purpose of this statement is to address methods of approval for retrofit shoulder harness installations in small airplanes.

NTSB Probable Cause

The pilot's negligent maintenance of the airplane, which resulted in improper fuel management, fuel starvation, and a loss of engine power during takeoff due to a missing securing pin in the fuel selector handle, and a subsequent forced landing on unsuitable terrain.