ANC97FA026

The pilot departed a remote airstrip with 10, five gallon gasoline cans of fuel. The pilot intended to transport the fuel to a remote trapping cabin. The airplane also contained full fuel (36 gallons) in the airplane fuel tanks, 50 pounds of traps and snares, and 35 pounds of survival equipment. The total (gross) weight of the airplane was estimated to be 1865 lbs; its maximum certificated gross weight was 1750 lbs. None of the cargo items were secured in the rear of the airplane. The airplane did not reach the intended destination, and was reported overdue. It was located 9 days later, about 300 yards southeast of the departure runway, in a steep, nose down attitude. When the airplane was located, all of the cargo items were found piled down and around the pilot.

History of flight

On February 7, 1997, about 1000 Alaska standard time, a ski equipped Piper PA-18, N121BB, collided with terrain at Circle, Alaska. The airplane was being operated as a visual flight rules (VFR) cross-country personal flight when the accident occurred. The airplane, registered to and operated by the pilot, was destroyed. The certificated private pilot, the sole occupant, received fatal injuries. Visual meteorological conditions prevailed.

On February 14, 1997, at 1957, friends and family of the pilot reported to the Federal Aviation Administration (FAA) the pilot was overdue on a flight from Circle City Airport that originated on February 7, 1997. The purpose of the flight was to deliver gasoline cans of fuel to a trapping cabin located in the Crescent River/Charley River area of the Yukon-Charley Rivers National Preserve. Fellow trappers and pilots indicated they became concerned about the flight when the accident airplane did not return to Circle by February 10, 1997. They had been searching for 2 days prior to reporting the flight overdue. The fuel cans were not located at the intended destination, and no evidence that an airplane had landed was observed.

On February 16, 1997, the airplane wreckage was observed by an airplane operating from the Circle City Airport. The wreckage was located about 300 yards southeast of the departure end of runway 15 at Circle, in an area of spruce trees. The fuel cans, each containing gasoline, intended for the trapping cabin, were located in the airplane wreckage.

The accident occurred during the hours of daylight at latitude 65 degrees, 49.265 minutes north, and longitude 144 degrees, 04.392 minutes west.

Crew information

The pilot held a private pilot certificate with an airplane single-engine land rating. The most recent third-class medical certificate was issued to the pilot on April 5, 1995, and contained no limitations.

The pilot's aeronautical experience listed on page 3 of this report, was obtained from a review of the airmen FAA records on file in the Airman and Medical Records Center located in Oklahoma City. On the pilot's application for medical certificate, dated April 5, 1995, the pilot indicated his total aeronautical experience consisted of 2,100 hours, of which 50 were accrued in the previous 6 months.

The pilot recorded recency of experience and biennial flight review information in his pilot logbook, but he did not record any total time. The pilot's spouse estimated his total aeronautical experience consisted of about 3,000 hours.

Aircraft information

The airplane had accumulated a total time in service of 5,397 hours. Examination of the maintenance records revealed that the most recent annual inspection was accomplished on July 15, 1996, 128.87 hours before the accident.

The engine had accrued a total time in service of 2,305.9 hours. The maintenance records note that a major overhaul was accomplished on August 1, 1993, 610.8 hours of operation before the accident. An annual inspection was accomplished on the date specified above for the airframe.

The airplane was last fueled at the Yukon Trading Post, Circle, Alaska, on February 6, 1997, with the addition of 12 gallons of 100LL octane aviation fuel, which filled the airplane's fuel tanks.

A weight and balance data sheet for the accident airplane, dated May 16, 1991, listed the airplane's empty weight as 1,074.1 pounds, with a center of gravity of 12.29 inches, and a useful load of 675.9 pounds. The maximum gross weight of the airplane is 1,750 pounds.

Meteorological information

Circle, Alaska, does not have a weather reporting station. The closest official weather observation station is Fort Yukon, Alaska, which is located 53 nautical miles north-northwest of the accident site. On February 7, 1997, at 0955, an aviation routine weather report (METAR) was reporting, in part: Wind, calm; visibility, 10 statute miles; sky condition and ceiling, 300 feet overcast; temperature, -12 degrees C; dew point temperature, -13 degrees C; altimeter, 29.76 inHg; remarks, automated observation without a precipitation discriminator.

The area weather forecast for the northern half of Alaska, issued from Fairbanks, Alaska, on February 6, 1997, at 2346, was reporting, in part: Upper Yukon Valley, forecast valid until February 7, 1997, at 1200. AIRMET for mountain obscuration. Fort Yukon and northwest, mountains obscured in clouds and precipitation, improving. ...Southeast of Fort Yukon; 4,000 feet scattered, 8,000 feet broken, 12,000 feet broken, tops of clouds, 15,000 feet; temporary, separate layers to 25,000 feet. Temporary, 4,000 feet broken in light snow. Outlook, valid from February 7, 1997, at 1200, to February 8, 1997, at 0600.

Residents of Circle reported areas of patchy low fog along nearby hills, but the area around the airport was clear.

Communications

There is no record of communications from the accident airplane. No emergency transmitter locator (ELT) signal was received from the airplane.

Aerodrome and ground facilities

The Circle City Airport is equipped with a single gravel surfaced runway on a 150/330 degree magnetic orientation. Runway 15 is 3,000 feet long by 60 feet wide, at an elevation of 610 feet msl.

Wreckage and impact information

The National Transportation Safety Board investigator-in-charge (IIC) examined the airplane wreckage at the accident site on February 18, 1997. The airplane collided with snow covered terrain in an area of small spruce trees about 300 yards southeast of the departure end of runway 15. The airplane was observed in a nose down attitude. The longitudinal axis of the cockpit, and the chordline of the wings, were oriented in a slightly inverted attitude, about 120 degrees from the horizon.

The fuselage, from the nose of the airplane to just aft of the rear window, was canted to the left, about 20 degrees from vertical. The tail of the airplane, aft of the rear window, was bent to the left about 25 degrees from its normal longitudinal axis. As a result, the entire fuselage was bent to the left about 45 degrees, with the outboard end of the left stabilizer resting above the trailing edge of the left aileron. The longitudinal axis of the airplane, from the tail to the nose, was oriented on a 180 degree magnetic heading.

All of the airplane's major components were found at the main wreckage area. The leading edge of the left wing exhibited an aft, flat, spanwise crushing signature, from the inboard attach point to about the outboard end of the left flap assembly. From the lift strut attach point to about the mid-chordline of the wing tip, the leading edge of the left wing was crushed aft at a 45 degree angle. The leading edge of the right wing, just inboard from the wing tip bow, displayed a semi-circular indentation and aft crushing over a small mound of snow and small spruce trees. Both wing lift struts remained attached to their respective wing and fuselage attach points.

The fuselage area, to the left of the front seat, was bent outward in a slight curve, and crushed into the snow. The instrument panel exhibited slight "U" shaped deformation toward the front of the airplane, and was also crushed into the snow. The front control stick was separated just above the forward edge of the front seat frame. The rear control stick was not installed.

The empennage was undamaged. The left landing gear ski assembly was pivoted upward at the tip, buried in the snow, and lying horizontal.

The flight control surfaces remained connected to their respective attach points. The flaps appeared retracted. The elevator trim tab jackscrew was found extended by 10 threads According to the airplane manufacturer, the extended trim tab jackscrew corresponded to a 1.5 degree elevator leading edge up, (a slight nose down) setting. The continuity of the flight control cables was established to the c