Aviation Accident Summaries

Aviation Accident Summary WPR09LA355

Truckee, CA, USA

Aircraft #1

N9772Y

BEECH 35-B33

Analysis

The pilot performed a preflight inspection, which included visually checking the fuel and oil levels. After starting the engine, all related instruments were in the normal operating range. The pilot then set up for a high-altitude takeoff, which included leaning the fuel mixture. He reported that the rotation was normal; however, at 400 feet above ground level (agl), the engine began to backfire and run rough. He enriched the mixture and engaged the auxiliary fuel pump with no change in engine operation. The stall warning horn sounded, so he lowered the nose and leveled the wings. The pilot stated that he thought he was at 300 feet agl when he began to look for a suitable landing area. He left the landing gear in the retracted position and held the airplane in a nose-high attitude until it impacted the ground. The airplane slid about 40 yards before it pivoted to the right and came to a stop. During the postaccident inspection, the engine was started and ran with no abnormalities noted. Additional testing of the fuel and ignition system components were accomplished. All components functioned on the manufacturer's test stands within specifications with no abnormalities detected.

Factual Information

On July 17, 2009, about 1945 Pacific daylight time, a Beech 35-B33, N9772Y, experienced a loss of engine power during the initial climb out and the pilot made a forced landing in the Martis Valley Wildlife area west of Highway 267 just south of Truckee, California. The pilot/owner, the sole occupant, operated the airplane under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. The pilot was not injured; the airplane sustained substantial damage to the fuselage belly keel beam. Visual meteorological conditions prevailed for the cross-country flight, and no flight plan had been filed. The flight departed from the Truckee-Tahoe Airport (TRK), Truckee, about 1940. It was destined for the Watsonville Municipal Airport (WVI), Watsonville, California. According to the pilot, he performed a preflight inspection, which included visually checking the fuel and oil levels. After start-up, all engine instruments were in the normal operating range. A high altitude takeoff was initiated, which included leaning the mixture. Rotation was normal; however, at 400 feet above ground level (agl), the engine began to backfire and run rough. The pilot stated that he enrichened the mixture, and engaged the auxiliary fuel pump, but the engine lost power, so he turned off the auxiliary fuel pump. The pilot reported that the stall warning horn sounded so he lowered the nose and leveled the wings. He stated that he thought he was at 300 feet agl when he began to look for a suitable landing area. He left the landing gear in the retracted position, and held the airplane in a nose high attitude until it impacted the ground about 55 miles per hour (mph). The airplane slid about 40 yards before it pivoted to the right and came to a stop. In a telephone interview with the National Transportation Safety Board (NTSB) investigator-in-charge, the pilot reported that the engine had recently been overhauled at the Teledyne Continental Motors (TCM) facility, and had about 20 hours of time in service since it was installed on the airframe. Investigators from the NTSB and TCM, along with an inspector from the Federal Aviation Administration (FAA), completed an examination of the engine at Truckee. There were no mechanical problems with the engine run. Various components were removed for additional testing. TCM personnel examined and completed functional tests of the following components at the factory in Mobile, Alabama, under the supervision of the FAA. A detailed report is in the public docket. All components functioned within specifications with no abnormalities detected. The link rod and levers of the throttle and fuel control assembly were intact and undamaged. TCM personnel removed the finger screen and observed no contamination. The unit was flow tested on the TCM test bench, and it functioned properly through its full range of operation. The fuel pump turned freely, and there were no abnormalities present. The pump was flow tested on the TCM test bench, and functioned properly through its full range of operation. The fuel manifold valve exhibited normal operating signatures. The fuel lines, nozzles, and manifold valve assembly were flow tested on the TCM test bench, and functioned properly through their full range of operation. There was no leakage observed from the cover vent port. The fuel nozzles were unrestricted and exhibited normal operating signatures. The fuel lines were intact and undamaged. The sparkplugs displayed normal wear signatures in accordance with the Champion aviation check-a-plug comparison chart. The left-hand magneto turned freely with impulse coupling engagement. The magneto was installed and tested on the test bench; it produced a blue spark across a 7 millimeter (mm) gap through the full range of test bench rpm. The right-hand magneto turned freely with impulse coupling engagement. The magneto was installed and tested on the test bench; it produced a blue spark across a 7 mm gap through the full range of test bench rpm.

Probable Cause and Findings

A loss of engine power during initial climb for undetermined reasons.

 

Source: NTSB Aviation Accident Database

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