Holdrege, NE, USA
N31698
PIPER PA-28R-201T
The pilot stated that the takeoff and climb were normal but that, about 700 to 1,000 feet above ground level, the engine stopped generating power even though the engine and propeller were still turning. Despite troubleshooting efforts, the pilot was unable to restore engine power; he stated that he heard intermittent backfire noise from the engine. While troubleshooting, the pilot banked the airplane back toward the airport but it was not at sufficient altitude to reach it, so he chose to land on a trail road. The pilot had to steer the airplane to the right to avoid a large pipe. Subsequently, the airplane's right wing contacted corn stalks, and the airplane came to rest in the cornfield. The airplane was equipped with an optional engine primer system, which included an electrically operated primer diverter valve connected to two primer nozzles, located in the metered fuel supply line between the air throttle valve and the manifold valve on each side of the engine. Actuation of the engine primer switch operates the auxiliary electric fuel pump and energizes the diverter valve that supplies fuel to each primer nozzle. Downloaded data from an engine monitor revealed that, about 2 minutes after takeoff, the fuel flow to the engine decreased from about 18 gallons per hour to about 2 gallons per hour and that four of the six cylinders' exhaust gas temperatures and cylinder head temperatures decreased rapidly. An examination of the wreckage revealed that the airplane's electric fuel pump activated when the battery was reconnected and the electric fuel pump selector was in the "off" position. The engine started, but it did not run smoothly. The engine was removed from the airplane and subsequently run in a test cell, and it was operational. The engine was test run again with the diverter valve electrically actuated; the engine subsequently ran roughly at low power and backfired. The panel-mounted primer switch was examined, and it did not exhibit any anomalies. The engine test run with the activation of the primer diverter valve duplicated the pilot's report of a loss of engine power and subsequent backfiring.
On July 19, 2013, about 1200 central daylight time, a Piper PA-28RT-201T, N31698, impacted high vegetation during a forced landing following a loss of engine power during climbout from the Brewster Field Airport (HDE), near Holdrege, Nebraska. The pilot who was the sole occupant was uninjured. The airplane sustained substantial wing damage. The airplane was registered to and operated by Altitude LLC under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Day visual flight rules (VFR) conditions prevailed for the flight, which did not operate on a VFR flight plan. The flight was originating from HDE at the time of the accident and was destined for the Mark Hoard Memorial Airport, near Leoti, Kansas. The pilot stated in his accident report that he was taking off from runway 36. The takeoff and climb out was normal. The pilot banked the airplane to the left and made a straight westerly track along the north side of the nearby town. About 700 to 1,000 feet above ground level, he "felt a complete power loss." The pilot indicated that the propeller and engine were still turning but not generating power. His first reaction was to lower the airplane's nose and apply full forward throttle. The mixture was already full forward and he turned on electric fuel pump. The pilot reported no change in engine performance. He switched from the right fuel tank to the left tank with no change in engine performance. The pilot tried left magneto, then the right magneto, and switched back to both magnetos with no engine changes. He could only hear intermittent backfire noise from the engine. While troubleshooting, he banked the airplane back towards the airport and did not have enough altitude to reach it. The pilot spotted a trail road and did not lower the landing gear until he was assured of reaching the road. The landing gear was down and locked with three green just before touch down. As the airplane rolled out on to the trail road, the pilot steered the airplane to the right to avoid a large pipe. The airplane's right wing began to contact corn stalks, which pulled the airplane into the cornfield where the airplane came to rest. The airplane was equipped with an optional engine primer system. According to the airplane's maintenance manual, the optional engine primer system is described as: A spring loaded OFF primer button switch, located on the instrument panel and is used to select HI auxiliary fuel pump operation for priming, irrespective of other switch positions. The primer button may be used for both hot or cold engine starts. On airplanes equipped with an optional engine primer system ... the primer switch location and actuation is the same as the basic airplane. However, this system does provide a separate primer system as an integral part of the engine fuel system. An electrically operated diverter valve is located in the metered fuel supply line between the air throttle valve and the manifold valve. Other components are two primer nozzles, located in the intake manifold on each side of the engine, the interconnecting fuel lines, and fine wire spark plugs. Actuation of the engine primer switch operates the auxiliary electric fuel pump on HI and energizes the diverter valve which supplies fuel to each primer nozzle. The diverter valve does not shut off all fuel flow to the manifold valve, therefore some quantity of fuel is also supplied to each cylinder nozzle during priming. Operation of the auxiliary fuel pump on HI and LO is unchanged. The airplane was equipped with JPI EDM 800 engine monitor. The monitor was shipped to the National Transportation Safety Board Recorder Laboratory for downloading. The downloaded data from the monitor for the accident flight revealed that about two minutes after takeoff, the fuel flow to the engine decreased from about 18 gallons per hour to about two gallons per hour. The exhaust gas temperatures and cylinder head temperatures for each cylinder decreased rapidly except for the number five and number six cylinders, which decreased slower. These two cylinders were located on opposite sides of the intake manifold. A safety representative from the engine manufacturer subsequently examined the wreckage under the supervision of a Federal Aviation Administration inspector. The airplane's electric fuel pump activated when the battery was reconnected and the electric fuel pump selector was in the off position. The engine started and did not run smoothly. The engine, marked as a Teledyne Continental Motors TSIO-360-FB(3) engine with serial number 281142-R, was removed from the airplane and was shipped to the engine manufacturer for an engine run in a test cell. The engine was run in a test cell under supervision of the investigator in charge and it was operational during the test run. The engine was run again and its diverter valve was electrically actuated. The engine subsequently ran roughly, produced little power, and backfired once the diverter valve was actuated. The panel mounted primer switch was examined and it did not exhibit any shorting between its leads. The airplane's pilot operating handbook emergency procedures, in part, stated: If the auxiliary fuel pump switch or primer switch fails causing the auxiliary fuel pump to be activated in the HI mode while the engine driven fuel pump is operating normally, engine roughness and/or power loss could occur. Should this condition exist; pull out the fuel pump pull-type circuit breaker, if so equipped or shut off the master switch.
The loss of engine power during takeoff due to the activation of the primer diverter valve.
Source: NTSB Aviation Accident Database
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