MIA99LA088

According to the pilot, he was indicating half full on his left main fuel tank, being vectored in IMC conditions by FAA Gulfport (Mississippi) Approach Control radar for an instrument landing, when he lost engine power. He thought that he had a least 12 to 15 gallons of fuel remaining. He could not regain engine power and ditched the airplane in the Gulf of Mexico. When the airplane was recovered 6 days later from the 6 to 8 feet depth water, about 12.5 to 13 gallons of uncontaminated blue colored 100LL aviation fuel remained in the left main fuel tank. Subsequent examination of the fuel system by FAA inspectors revealed a clogged left wing fuel vent system.

On February 18, 1999, about 1245 central standard time, a Beechcraft K-35, N15FF, registered to a private individual, operating as a Title 14 CFR Part 91 personal flight, ditched into the Gulf of Mexico in the vicinity of Gulfport, Mississippi. Instrument meteorological conditions (IMC), prevailed and an IFR flight plan was filed. The aircraft sunk and the commercial-rated pilot, the sole occupant, was not injured. The flight departed Homestead Municipal Airport, Florida, at about 0922 eastern standard time.

According to FAA Gulfport-Biloxi Regional Tower personnel, the flight was on a downwind leg in IMC conditions, in preparation for an ILS approach to runway 32, when the pilot radioed that he had an engine problem and was ditching the airplane.

According to the pilot, the flight was uneventful until the engine lost power while being vectored by FAA Gulfport Approach Control Radar in IMC conditions at 3,000 feet msl. As he emerged from the clouds at 900 feet msl, he was over the Gulf of Mexico, but was too low to stretch his glide to the beach. He stated his fuel selector was on "left-main tank", and he thought it contained about 12 to 15 gallons remaining. In subsequent statements, the pilot said the fuel selector was on "left-main tank" when the engine lost power, and fuel pressure went to zero, and he switched through all positions; from "left-main" to "left-aux" to "right-main" to "right-aux" back to "left-main", but to no avail. He stated he did not operate his electric auxiliary fuel pump.

According to an FAA inspector, postcrash examination of the wreckage revealed the airplane was equipped with auxiliary wing fuel tanks (10 gallons each), and tip tanks (12 gallons each), in addition to the main tanks (25 gallons each). The left main tank contained 12.5 to 13 gallons of blue colored, uncontaminated aviation fuel. The left auxiliary tank contained about 5 gallons of a fuel-water mixture. The right main and auxiliary tanks contained sea water with little trace of fuel. The left tip was empty and the right tip was destroyed. The fuel selector was found in the "right-main tank" position. The engine checked satisfactory for accessory drive train, valve train, and piston continuity. Engine-driven fuel pump operation and its gear drive checked satisfactory. The fuel feed line to the fuel flow divider contained about 3 to 4 tablespoons of uncontaminated fuel. No fuel was found in the flow divider or downstream of the divider to the cylinders.

Subsequent examination of the fuel venting system by an FAA inspector revealed that the left wing vent line was obstructed near its vent port at the wing tip. The material clogging the vent line appeared to be a piece of sponge. The obstruction was sufficient to prevent any venting and was so tightly lodged in the vent line that use of compressed air was insufficient to dislodge it, and it had to be mechanically removed.