Aviation Accident Summaries

Aviation Accident Summary BFO94LA025

POUGHKEEPSIE, NY, USA

Aircraft #1

N930T

BEECH 33

Analysis

AFTER PRE-HEATING THE AIRPLANE, AND AFTER A PRE-FLIGHT INSPECTION WHICH REVEALED NO DISCREPANCIES OR CONTAMINATED FUEL, THE PILOT TOOK OFF AND CLIMBED TO 2,220 FEET MSL. ABOUT 30 SECONDS AFTER SELECTING CRUISE POWER, THE ENGINE LOST PARTIAL POWER. THE ENGINE WAS 'BARELY KEPT ALIVE' BY USE OF THE AUXILIARY FUEL PUMP, BUT FULL POWER COULD NOT BE REGAINED DESPITE THE COMPLETION OF THE EMERGENCY CHECKLIST. A FORCED LANDING WAS MADE IN A WOODED AREA, AND THE AIRPLANE STRUCK TREES. AN EXAMINATION OF THE AIRFRAME AND ENGINE DID NOT REVEALED ANY PRE-IMPACT DISCREPANCIES WHICH WOULD HAVE LED TO A PARTIAL POWER LOSS. THE TEMPERATURE AT THE TIME OF THE ACCIDENT WAS ZERO DEGREES. FUEL WAS FOUND IN THE GASCOLATOR. ALL OF THE SPARK PLUG LEADS WERE BLACK AND WORN. THE AIRPORT FUEL SUPPLY WAS TESTED WITH NO DISCREPANCIES NOTED. THE ENGINE HAD A HISTORY OF HIGH OIL CONSUMPTION.

Factual Information

On January 16, 1994, about 0938 hours eastern standard time, N930T, a Beech BE-33, operated by the owner/pilot, collided with trees and was substantially damaged during a forced landing near Poughkeepsie, New York. The forced landing was precipitated by a loss of engine power. The certificated private pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed and a flight plan was not filed. The personal flight departed from Poughkeepsie about 0900 hours and was destined for West Chester, Pennsylvania. The flight was conducted under 14 CFR 91. The pilot stated that he had recently purchased the airplane on December 28, 1993. When he took possession of the airplane, the engine required the addition of six quarts of oil. During the flight from Chicago to New Hampshire, an additional seven quarts of oil were needed. One day prior to the accident, the pilot flew the airplane from New Hampshire to the Duchess County Airport in Poughkeepsie. The pilot stated that during the flight, he was unable to lean the fuel mixture below a reading of 8 pounds per square inch (psi). He stated that the "normal" fuel pressure reading should be about 5 psi after leaning. He stated that he was flying at an altitude of 10,500 feet mean sea level (msl) at the time he attempted to lean the mixture. Upon landing in Poughkeepsie, the airplane was "topped" off with 31 gallons of 100 low lead aviation gasoline. The pilot stayed overnight in Poughkeepsie with plans to depart for West Chester, Pennsylvania, the next morning. On the morning of the accident, an additional two quarts of oil were added to the engine. The pilot pre-heated the airplane for about 45 minutes, and then pre-flighted the airplane. During the pre-flight inspection, the pilot drained fuel from both wing fuel tanks and did not detect any ice, water, or contamination. He started the engine and ran it up for about 20 minutes with no problems noted. The pilot then took off from runway 24 and climbed to about 2,200 feet msl. About 30 seconds after selecting cruise power, engine power decreased to idle and the oil pressure dropped. The pilot turned back toward the departure airport and attempted to regain engine power. He stated that he switched from the left fuel tank to the right and activated the electric fuel pump. The engine was "... barely kept alive," despite the completion of the emergency checklist. Realizing he would not make it to the airport with the idling engine, he force landed the airplane in a "hole" surrounded by trees. According to an FAA aviation safety inspector, the airplane came to rest upright after impacting trees in a wooded area. Both wings were substantially damaged and both fuel tanks were compromised. A special surface weather observation was recorded at the Duchess County Airport at the time of the accident. The airport is located about one mile from the accident site. The observation reported clear skies, calm winds, and a temperature of zero degrees F. A sample of fuel from the airport's fuel supply used by the pilot was tested by airport authorities. No contamination was found. Other pilot's operating from the airport on the day of the accident were asked by Air Traffic Control (ATC) tower personnel to report any engine malfunctions. None were reported. The airplane was removed from the accident site and examined at the Duchess County Airport by the FAA on February 16, 1994. A report of the examination is attached. The engine, a Continental IO-520 was removed from the airframe and examined. Oil was found in the engine. Crankshaft and valve train continuity was verified. According to the FAA report: "Removed all spark plugs, found all carbon black and excessive wear of center electrode. Go/no go gage also indicated that all spark plugs were worn.... Three spark plugs were not threaded all the way and torqued." On April 29, 1994, a mechanic examined the gascolator on the airframe. Fuel was found in the gascolator and in the fuel lines attached to it. No evidence of water or contamination was found. The fuel distribution valve was disassembled and examined. There was no evidence of fuel or rust. An examination of the airframe and engine maintenance logbook (excerpts attached) revealed that the airframe and engine received an annual inspection and a 100-hour inspection on September 3, 1993. No unresolved or open discrepancies were noted. The engine had logged a total of 435 hours since major overhaul, and 12 hours since its last inspection.

Probable Cause and Findings

THE PARTIAL LOSS OF ENGINE POWER DUE TO UNDETERMINED REASONS. RELATED TO THE ACCIDENT WAS THE LACK OF SUITABLE TERRAIN TO COMPLETE A SUCCESSFUL FORCED LANDING.

 

Source: NTSB Aviation Accident Database

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