ANC98MA008

The pilot, who was also the station manager, arrived at the airport earlier than other company employees to prepare for a scheduled commuter flight, transporting seven passengers and cargo to another village during hours of arctic, predawn darkness. Heavy frost was described on vehicles and airplanes the morning of the accident, and the lineman who serviced the airplane described a thin glaze of ice on the upper surface of the left wing. The pilot was not observed deicing the airplane prior to flight, and was described by the other employees as in a hurry to depart on time. The pilot directed the lineman to place fuel in the left wing only, which resulted in a fuel imbalance between 450 and 991 pounds (left wing heavy). The first turn after takeoff was into the heavy left wing. The airplane was observed climbing past the end of the runway, and descending vertically into the water. No preimpact mechanical anomalies were found with the airplane or powerplant. The aileron trim indicator was found in the full right wing down position. Postaccident flight tests with left wing heavy lateral fuel imbalances, disclosed that approximately one-half of right wing down aileron control deflection was used to maintain level flight, thus leaving only one-half right wing down aileron control efficacy. Research has shown that frost on airfoils can result in reduced stall angles of attack (often below that required to activate stall warning devices), increases in stall speeds between 20% and 40%, asymmetric stalls resulting in large rolling moments, and differing stall angles of attack for wings with upward and downward deflected ailerons (as when recovering from turns).

History of flight

On November 8, 1997, at 0808 Alaska standard time, a Cessna 208B airplane, N750GC, was destroyed when it impacted water in the Arctic Ocean, about one-half mile west of Barrow, Alaska. The airline transport certificated pilot, and the seven passengers on board, sustained fatal injuries. The airplane was operated by Hageland Aviation Services, Inc., of St. Mary's, Alaska, under 14 CFR Part 135, as scheduled commuter Flight 500. The destination was Wainwright, Alaska. Night, visual meteorological conditions (VMC) prevailed at the time of the accident, and a VFR flight plan was filed.

At 0802, the pilot radioed to the FAA Flight Service Station (FSS) that he was taxiing for takeoff, and filed a flight plan to Wainwright with eight persons on board, two hours en route, and three hours of fuel. At 0804, the pilot reported that he was back taxiing for runway 24. At 0806, he transmitted that he was departing runway 24. At 0808, two annunciations of an Emergency Locator Transmitter(ELT) were heard on 121.5 MHz by the FSS specialist on duty.

The pilot of a Cessna 207 which had earlier departed runway 06 for Wainwright reported hearing the pilot say, "mayday, mayday" and that he saw the airplane's lights descend "straight down into the water." The witness pilot had been talking previously to the accident pilot on 127.77 MHz, and overheard the "mayday" call on that frequency. The witness pilot revealed that he was at 700 feet MSL, and that the accident airplane never reached his altitude.

The airplane came to rest submerged in twenty-one feet of water, approximately 200 yards offshore. The fuselage and left wing were recovered the evening of the accident, with the right wing, engine, and various other components recovered separately over the next two day period.

One passenger occupied the right-front crew seat, five passengers occupied the installed passenger seats, and a single infant was being held by her mother as a lap child. All occupants were recovered from the interior of the airplane, still restrained in their seats, except for the infant, who was located in the aft cabin.

The accident flight was the company's first flight of the day. The lineman who assisted the pilot prepare the airplane for departure, told the NTSB investigator-in-charge (IIC) that after he fueled the airplane's left wing, there were no "ribbons or strings" hanging down from the airplane, and there were no covers on the pitot tubes. The lineman, and the company dispatcher who was helping prepare the flight, described the pilot as "the same as he always was," and in a hurry to make the scheduled takeoff time.

Damage to aircraft

The airplane was destroyed by a combination of impact forces and recovery damage. The airplane was described by the divers who first arrived on scene to be resting upright on the ocean floor in 21 feet of water. The wings were attached to the fuselage, but the engine was not. These divers described the leading edges of both wings as damaged. During recovery of the airplane, ropes were attached to the wing struts and landing gear, for towing by boats. While being towed, the airplane rolled over, and the right wing separated. The left wing remained attached by cables.

Personnel information

The pilot held an airline transport pilot certificate for multiengine airplanes, and a commercial pilot certificate for single-engine airplanes. His first class medical certificate contained no restrictions. He also possessed an airframe and powerplant mechanic license. The pilot was first hired by the company as the station manager at McGrath, Alaska, on June 23, 1994. He had been employed by the operator as the station manager in Barrow since June of 1997, and had flown 220 hours in the Barrow area. According to the company president, the pilot's primary duty was to manage the station, and he was not required to fly as a pilot. The pilot's wife said he enjoyed flying, and normally would take the first flight in the morning, which then allowed him to concentrate on his management duties for the remainder of the day.

The pilot was qualified in Cessna 185, 206, 207, and 208 airplanes. At the time of the accident, he had accumulated about 3,500 hours of flight time. Between June 23 and 27, 1997, he attended initial training in the Cessna 208B at Flight Safety International, Inc., Wichita, Kansas. The pilot had accrued 161 hours of experience in the Cessna 208B, and had flown 20.1 hours in the week prior to the accident, all in the Cessna 208B.

The pilot's most recent 14 CFR Part 135 proficiency check was conducted on June 27, 1997, as part of his initial qualification in the Cessna 208B.

Aircraft information

General

The airplane was a Cessna 208B "Grand Caravan," manufactured in January 1996, by the Cessna Aircraft Company, Inc., of Wichita, Kansas. The airplane was operated as a company demonstration aircraft by Cessna Aircraft Company, Inc., until it was sold on May 16, 1997, to Gussic Ventures, Inc., of Anchorage, Alaska, who leased it to Hageland Aviation Services, Inc. The airplane was powered by a single Pratt & Whitney PT6A-114A turboprop engine, rated to produce 675 shaft horsepower. The airplane had accumulated 1,438 total hours in operation at the time of the accident.

The airplane was equipped with the capability of seating up to nine passengers. At the time of the accident, five passenger seats were installed. The remaining seats were stowed in the aft cargo compartment, to make room for a casket being carried as cargo in the cabin. The airplane also carried a cargo pod installed underneath the belly of the airplane.

The airplane was equipped for flight into instrument meteorological conditions (IMC), although at the time of the accident, the company's FAA approved Operating Specifications did not authorize passenger carrying operations in single-engine airplanes during IMC.

The airplane was maintained on a Cessna periodic maintenance schedule, under an Approved Aircraft Inspection Program (AAIP). This was approved on the company's Operations Specifications in paragraph D73. This AAIP was developed from the Cessna Aircraft Company Recommended Maintenance Program for the Cessna 208B airplane. It was comprised of 12 "Phase" inspections, one accomplished each 200 hours, with "mini" checks each intermediate 100 hours. When utilizing this AAIP, the entire aircraft is inspected with the completion of any four consecutive phase inspections. All inspections were current at the time of the accident. The most recent maintenance performed was a "Phase 4" inspection completed on November 1, 1997, 28 hours prior to the accident.

A review of maintenance records revealed no repetitive maintenance problems, except for a captain's Heading Situation Indicator (HSI) replacement on June 19, October 27, October 28, and October 29, 1997. No further discrepancies with the captain's HSI were noted. The accident airplane was flown on three flights by a different pilot on November 7, the day prior to the accident. This pilot did not recall any discrepancies with the airplane.

Weight and Balance

When questioned on how much fuel remained in the airplane when he returned from the final flight on the evening of November 7, the previous pilot told the Safety Board that he believed the airplane had approximately 600 to 700 total pounds of fuel, with 350 pounds in each wing. He did not fuel the airplane upon his return from the flight which preceded the accident.

The morning of the accident flight, the pilot directed that the left wing be "topped off" by a new employee. This was the employee's second day on the job, and he had no previous experience working on, or around, airplanes. When interviewed by the NTSB operations group chairman, he described unrolling the fueling hose from its storage location, and fueling the left wing until fuel "sloshed" out of the