Aviation Accident Summaries

Aviation Accident Summary ANC00LA015

DILLINGHAM, AK, USA

Aircraft #1

N9933M

Cessna 207A

Analysis

After takeoff the airplane did not climb above 30 feet, drifted left of the runway, and settled onto the ground. The pilot stated the engine 'missed, quivered, and lost power.' He also stated there was light frost on the airplane, but that other small airplanes had departed with similar frost. The engine had been installed on the airplane the day prior to the accident, and had been operated on the ground, but not flown. After the accident, an undamaged propeller was installed, and the engine was operated at 1,000 rpm for 4 minutes. The engine-driven fuel pump, fuel controller, and fuel distributor and nozzles were tested. These components all produced the normal fuel flows and pressures specified by the manufacturer.

Factual Information

On November 16, 1999, at 1020 Alaska standard time, a Cessna 207A airplane, N9933M, sustained substantial damage when it impacted terrain 50 feet west of runway 01 during takeoff from the Dillingham Airport, Dillingham, Alaska. The solo commercial pilot received minor injuries. The flight was operated by Yute Air Alaska, Inc., of Anchorage, Alaska, under 14 CFR Part 135 as a cargo and mail flight to New Stuyahok, Alaska. Visual meteorological conditions prevailed at the time of the accident, and a company VFR flight plan was in effect. During a telephone interview with the NTSB investigator-in-charge (IIC) on November 17, the pilot stated that he taxied to the end of the 6,404 feet long by 150 feet wide runway, and made a full length takeoff. He said the pretakeoff engine runup was normal, as was the takeoff run and liftoff. He indicated that about 30 feet above the ground, the engine "missed, quivered, and lost power." The pilot also stated that the low voltage light came on between the takeoff and impact. He said the airplane drifted to the left of the runway, he was not able to get back over the asphalt before contacting the ground, so he leveled the wings and landed. The nose landing gear broke off, and the airplane nosed over. He told the NTSB IIC that the cargo load was 1,100 pounds, and the airplane contained about 1/2 of a full fuel load. The weather observation for Dillingham at 0950 was: wind from 040 degrees at 5 knots, 20 miles visibility, a ceiling of 1,000 feet overcast, a temperature of 7 degrees Fahrenheit, and a dew point of 3 degrees Fahrenheit. Witnesses described light frost on airplanes parked at the airport the morning of the accident. The pilot told the NTSB IIC that there was light frost on the airplane, but no more than he had seen before. He added that other small airplanes had departed that morning with frost adhering to their wings. The NTSB IIC estimated the takeoff weight between 3,700 pounds and 3,800 pounds. The maximum allowable takeoff weight for the Cessna 207A is 3,800 pounds. The accident flight was the first flight since the engine and propeller assembly was replaced. The engine had been ground operated, but not flown, since installation on this airplane. The engine had about 800 hours since overhaul, and about 5 hours in operation on a different airplane since a teardown inspection for a propeller strike. On December 20, 1999, an undamaged propeller was installed on the accident engine, and the engine operated on the airframe by an FAA airworthiness inspector. The engine started, and was operated up to 1,000 rpm for four minutes. Due to possible crankshaft damage, the engine was not operated at a higher power. The crankshaft was subsequently removed for non-destructive inspection, and found to be cracked. The mechanical fuel pump, fuel controller, and fuel distribution manifold were removed and flow tested on April 3, 2000, under supervision of an NTSB investigator. Flow rates and discharge pressures of all three components were found to meet the manufacturer's specifications.

Probable Cause and Findings

Failure of the pilot to remove frost from the wings prior to flight, and the resulting inadvertent stall/mush.

 

Source: NTSB Aviation Accident Database

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