Aviation Accident Summaries

Aviation Accident Summary SEA97LA162

W. YELLOWSTONE, MT, USA

Aircraft #1

N3425Q

Cessna 320E

Analysis

The private pilot attempted to compensate for crosswind conditions during final approach in the twin-engine airplane with the use of power. He began to drift off the east (left) side of the runway, and he stated that the right engine did not respond to throttle inputs during the landing. He lost directional control of the airplane and impacted rough, grassy terrain off the edge of the runway. The landing gear collapsed and the airplane was substantially damaged. Examination of both propellers revealed damage consistent with applied power on the left engine, and no power on the right engine. An examination of the maintenance records revealed that the engine had recently been rebuilt by the manufacturer and installed on the airplane. Prior to the accident flight, it underwent an annual inspection and was operated for 6.2 hours during six flights with no problems noted. An examination of the right engine throttle controls and a functional test of the right engine did not reveal any evidence of preimpact mechanical discrepancies that would have resulted in a power loss or hesitation.

Factual Information

On July 18, 1997, about 1630 mountain daylight time, N3425Q, a Cessna 320E, operated by the owner/pilot, collided with terrain during landing and was substantially damaged at an airport in West Yellowstone, Montana. The private pilot was not injured, and his three passengers received minor injuries. Visual meteorological conditions prevailed and no flight plan had been filed. The personal flight departed from Ogden, Utah, and was en route to West Yellowstone. The flight was conducted under 14 CFR 91. In a written statement sent to the Safety Board (attached), the pilot stated that he entered the traffic pattern for a left downwind entry for a full stop landing on runway 19 at the Yellowstone Airport. He noted that the wind sock was "fully extended" and indicated a "slight [left] crosswind." While on final approach, at 100 knots, and with the flaps fully extended, the pilot "pulled back" both throttles. About 50 feet above the runway, the pilot pulled both throttles to idle and the airplane slowed to 80- knots. The pilot further stated: [There was a] sudden increase [in the left] crosswind and some descent. Throttles pushed forward to correct descent and overcome crosswind affect [sic]. Left engine surged. Right engine did not respond. Aircraft jumped like a bucking horse 90 [degrees] to right heading toward trees - left engine had no affect [sic]. Hit ground within 3 - 4 seconds. Airplane rotated 160 degrees." According to a Federal Aviation Administration (FAA) aviation safety inspector from Helena, Montana, the airplane came to rest about 100 feet to the west of the western edge of runway 19 about mid-field. The airplane was resting upright on top of its collapsed main landing gear. The outboard portions of both wings and the tail surfaces were substantially damaged. An examination of the left propeller revealed that all three blades were bent opposite the direction of rotation. The right propeller blades were all bent aft. Engine control cable continuity for the right engine was confirmed by the FAA inspector at the accident site. A 1/8-inch pipe plug was found lying on the underside of the cowl of the right engine. The plug could be fit into a boss on the left rear induction elbow that was meant for a manifold air pressure gauge line. The airplane was powered by two fuel-injected, reciprocating, turbocharged Continental TSIO-520 engines rated at 285 horsepower each. An examination of the airplane maintenance records (excerpts attached) revealed that both engines had been recently rebuilt by their original manufacturer, Teledyne Continental Motors. The right engine, serial number 176726, "satisfactorily" completed the manufacturer's engine test specifications on April 9, 1997, prior to shipment to the owner/operator. The records further indicate that the right engine was installed on the accident airplane and successfully test run on June 12, 1997. The airplane received an annual inspection at that time with no unresolved maintenance discrepancies noted. Copies of the pilot's personal log book and observations of the airplane's Hobbs hour meter indicated that the airframe and engines had operated for 6.2 hours during six flights subsequent to the most recent annual inspection. No discrepancies were recorded or reported during this time. The Safety Board obtained custody of the right engine for examination and test (results attached) under Safety Board supervision. The engine was mounted on an engine test stand at the Teledyne Continental Motors factory in Mobile, Alabama, on December 3, 1997. The exhaust runners were removed from the engine and a slaved exhaust system was installed. The propeller, rear mounted throttle/fuel metering unit, turbochargers, and wastegate were not shipped with the engine; therefore, slaved units were installed for the test. Engine start-up was immediate, and the engine ran smoothly. After warm-up, with the 1/8-inch pipe plug not installed, the propeller was adjusted for 2,700 rpm, the throttle was moved full forward, and the manifold air pressure was set at 32 inches. No anomalies were noted. The engine was then run at idle. No anomalies were noted. The engine was shut down and the 1/8-inch pipe plug was installed into the right induction elbow. The engine was restarted and run again at full throttle and at idle with no anomalies noted. The engine was also tested for acceleration by slamming the throttle from idle to full. Acceleration was smooth and immediate. There was no change in acceleration with or without the 1/8-inch pipe plug installed in the induction elbow. The pilot, a 56-year-old medical doctor, held an FAA Private Pilot Certificate with ratings for airplane single-engine land, airplane multi-engine land, and instrument airplane. He had logged a total of 1,733 flight hours, including 283 hours of multi-engine time, and 163 hours in type. According to a recorded surface weather observation taken at the Yellowstone, a left crosswind of 18 knots prevailed about the time of the accident. The right engine was released to Mr. Charles E. Carstensen, Carstensen Company Air Accident Adjusters, Montrose, Colorado, on February 18, 1998. Mr. Carstensen was representing the owner/operator of the engine at the time of the release.

Probable Cause and Findings

The pilot's failure to maintain directional control during landing when asymmetric power was applied. A factor was the crosswind conditions.

 

Source: NTSB Aviation Accident Database

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