Versailles, MO, USA
N9144E
JOHNSTON WILLIAM ALFRED JR KOLB MARK III
The pilot stated that the accident occurred on his sixth flight in the airplane. The engine run-up for the accident flight was normal, and just after takeoff, the engine over-temperature warning light illuminated. He banked the airplane to return to the airstrip. He said he decreased the engine power to keep the temperatures down but then had to increase engine power and pitch in order to clear trees along the flight path. The engine subsequently stopped producing power. The landing gear was ripped off during the forced landing in a field and the pilot was dragged across the terrain while still in the sling-type seat, which resulted in the pilot sustaining serious back injuries. After purchasing the airplane, the pilot installed a new engine, a ballistic recovery chute, a new fuel tank, and new fuel lines. However, he stated that he had continuing problems with high engine temperatures and a high static engine rpm. In response to these problems, the pilot replaced the static jets in both carburetors, tuned and synchronized both carburetors, and replaced the heat probes. He also installed an engine information system. A postaccident examination of the engine and airplane revealed that both carburetors were not adjusted properly, thus restricting fuel flow; improper fuel jets were installed, which produced a richer fuel/air mixture; and the coolant water temperature probe was in the wrong location, which would have prevented accurate temperature sensing. In addition, the positions of the air deflectors, the ballistic recovery chute, and the oil injection reservoir may have affected the amount of cooling air to the engine. No evidence of internal damage was noted to the pistons and cylinders. The engine demonstrated the ability to run normally during postaccident testing. Although the exact cause of the loss of engine power was not determined, it is likely that a combination of the modifications that were made to the airplane and engine that resulted in the loss of engine power.
On October 5, 2011, at 1730 central daylight time, an amateur-built Johnston Kolb Mark III, N9144E, collided with the terrain during an off airport forced landing following a loss of engine power on takeoff from a private airstrip in Versailles, Missouri. The student pilot was seriously injured. The airplane that was registered to and operated by the pilot sustained substantial damage. The personal flight was operating under 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed. The flight was originating at the time of the accident. The pilot stated the accident occurred on his sixth flight in the airplane. The engine run-up was normal so he decided to fly it around the traffic pattern at the private airstrip. He stated that just after takeoff, as he was over a wooded area, the over temperature warning light illuminated. He banked to return to the airstrip and decreased the power to about 1,190 rpm in order to keep the engine temperatures down. However, he subsequently increased the engine power and pitch attitude in order to clear the trees along the flightpath. The airplane was over a bean field when the engine subsequently stopped producing power. The pilot stated that the landing gear was ripped off when he landed the airplane in the field. He was drug across the terrain while still in the sling type seat which resulted in the serious back injuries that he sustained. The pilot purchased the already built airplane in May 2010. After purchasing the airplane he installed a new engine, a ballistic recovery chute, a new fuel tank, and new fuel lines. He stated he took the airplane to the Kolb factory to have it inspected. He stated that he was having problems with the number 2 cylinder exhaust gas temperature (EGT) running hot. He was also having problems with the number 1 cylinder head temperatures and the static run rpm. He stated that the maximum allowable rpm was 6,200 and he was achieving 6,280 rpm. He was advised by the repair station where he purchased the engine that the static jets could have been the problem so he replaced both of them. The pilot also installed an engine information system (EIS). He stated that the engine operated within parameters during a ground run-up. During takeoff on the first flight after installing the EIS, the number 2 cylinder EGT indicated high. He once again contacted the repair station and was told that the carburetors might need to be tuned and synced, which he did. He stated he flew the airplane again and encountered the same problem, so he replaced the heat probes and the engine information system (EIS). Due to the extent of the pilot’s injuries he was unable to complete the NTSB Pilot/Operator Aircraft Accident /Incident Report. A postaccident examination of the engine revealed: Both the magneto side (MAG) and the power takeoff side (PTO) carburetor piston slides were not adjusted properly and were found to be protruding past the carburetor body. This would result in the jet needles being in too low of a position, restricting fuel flow resulting in a higher EGT. The main jet on both carburetors was a number 170 which would produce a richer mixture instead of the normal 165 jet. The fuel filter was located between the fuel pump and fuel tank instead of between the fuel pump and the carburetors as specified in the Rotax installation manual. Small air deflectors were attached to the radiators to direct airflow into them for additional cooling. The left hand radiator was partially blocked by the oil injection tank. The ballistic recovery chute was mounted directly in front of the engine. It is unknown how these items affected airflow to the engine. The coolant water temperature probe was mounted in the outlet socket after the thermostat instead of being mounted in the center of the cylinder head as recommended. This location would prevent the probe from sensing the proper coolant temperature. The injection oil tank was approximately half full of oil. The pistons and cylinders did not show evidence of damage or lack of lubrication. With the propeller blades removed, due to damage, the propeller hub was reinstalled so the engine could to be test run. Both magneto switches were turned on. While spraying raw fuel into the intake of both carburetors the engine started and ran for a few seconds until the fuel was removed. The engine was started a second time and it ran for approximately 10 seconds before the fuel source was removed.
A loss of engine power due to adjustments and modifications that the pilot made to the engine and airplane.
Source: NTSB Aviation Accident Database
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