Alaska

The flight departed with 180 pounds of cargo after deplaning a passenger. Three company pilots overheard the accident pilot report that he was 13 minutes from his destination. The overdue aircraft was located by company airplanes about 700 feet MSL, on the east (downwind) side of an 890 feet msl pass. The airplane impacted on a 330 degree heading and perpendicular to the axis of the canyon/pass (oriented east-west), in a flat attitude, with no ground scars leading to the wreckage. No anomalies were found with the airplane, and all blades on the propeller exhibited torsional twisting and leading edge gouging. A westerly wind of seven to nine knots existed and numerous pilots reported the mountain passes were not obscured by clouds. Photographs from the pilot's camera depicted views of the accident canyon, with the pass and accident site above the altitude from which the photographs were taken. These photographs contained the date of the accident. Numerous depressant and stimulant, over-the-counter cold and asthma medications were found in the pilot's flight bag. Toxicological tests detected several over-the counter medications used for cold and asthma symptoms with illness effect of distraction or sensory disturbance. As a result of the condition for which the drugs were ingested may have also played a role in the accident.

The aircraft had an in-flight breakup when the left wing and tail section separated. Post accident inspection revealed a right engine main fuel supply line progressive rupture, only trace amounts of fuel in the fuel lines, and no rotational damage to the right engine. Pre accident, long term, fuel leak evidence surrounded the ruptured line. The right propeller was not feathered. The left wing D-tube rib at station 127 exhibited compressive buckling. Left wing fractures were upward, and horizontal stabilizer deformation was downward. During an actual loss of engine power in the airplane 17 months before this accident, the pilot had feathered the incorrect propeller. Both a mechanic, and an FAA safety counselor, who were familiar with the pilot, described him as able to be disoriented, and reliant on GPS for navigation. He had stated five months before the accident that he did not feel his instrument flying skills were proficient, and desired training. On the day of the accident, weather was visual meteorological conditions, with layered clouds above 2,200 feet mean sea level. The pilot stated to the FAA weather briefer that he wanted to make the flight under visual conditions. The flight route and altitude was unknown.

The pilot boarded the 4 passengers and cargo (unsecured) for a chartered flight to a fishing lodge. The floatplane departed uneventfully. About 45 min. later, while cruising about 1,700 feet above rugged terrain and a river, the engine began to lose power and the floatplane descended. The pilot attempted a forced landing in a small lake that was 1,200 ft. in length and located about 1 mile west of the river. During the approach to landing, the airplane stalled and impacted swampy terrain at the lake's edge in a steep nose down attitude. An examination of the wreckage revealed that the no.1 engine exhaust pushrod had failed in fatigue just below the top (valve) ball end. Examination of the pushrod revealed that material had been pushed away from the rod during installation of the ball end. The fatigue crack may have initiated from a score mark produced by the installation. Pushrod life is reduced due to surface scratches. The life of the failed pushrod could not be determined. Insufficient information exists in the overhaul manual regarding pushrod life/inspection.

The air cargo flight had just off loaded its cargo at a remote site. Shortly after takeoff, the number two engine begin to run rough. The engine was shut down, and the propeller feathered. During the shutdown process, a fire warning light illuminated, and fire became visible near the number 2 engine. The crew activated both banks of engine fire extinguishers, but were unable to extinguish the fire. While on approach to an off-airport emergency landing site, the number two engine fell off and ignited a brush fire. The crew made a successful landing and ran away from the airplane. The airplane continued to burn and was destroyed by fire. The number 2 engine was not recovered or located.

The flight was landing under special VFR conditions. Special VFR operations are permitted with a visibility of 1 mile, and clear of clouds. The airport was the pilot's base of operations. The flight had held outside the airport surface area for 26 minutes, waiting for a special VFR clearance. While outside the airport surface area, the pilot was required to maintain 500 feet above the ground and 2 miles visibility. While holding, the weather at the airport was reported as 300 feet overcast. The visibility decreased from 4 miles to 1 mile in mist. The pilot was new to the area of operations, having worked at the company for 24 days, during which he accrued 69 hours of flight time. Four minutes after receiving clearance to enter the surface area for landing, the airplane collided with a 260 feet tall radio antenna tower at 222 feet above the ground. The tower was located 3.85 nautical miles east of the airport. The radio tower was not considered by the FAA to be an object affecting navigable airspace, but was depicted as an obstruction on the VFR sectional chart for the area. The tower was equipped with obstruction lighting for night illumination, and was painted alternating aviation orange and white for daytime marking. One minute after the collision, the overcast was reported at 200 feet, and the visibility was 5/8 mile.

The pilot took off from a 4400-foot-long gravel airstrip with a near gross weight load of cargo. He said that shortly after lift-off the airplane felt 'sluggish', and he believes the left engine began to lose power. He said the airplane would not climb, and he elected to bring both engines to idle and land on the remaining runway. The airplane touched down a short distance from the end of the runway, and continued off the end and into the woods. A fire erupted, and the airplane was destroyed by fire. The pilot is unsure if the fire occurred in the air, or shortly after the airplane went off the end of the runway. The engines were extensively damaged by fire, and were not examined. FAA inspectors on scene said there was no obvious signs of catastrophic engine failure.

The pilot had contacted the FSS 11 times on the day of the accident to obtain weather briefings. The conditions were below VFR minimums, which were required to conduct the passenger carrying commercial flight in a single-engine airplane. The conditions later improved and the pilot departed under a special VFR clearance. The pilot performed two approaches at the destination airport in IMC that were consistent with the two GPS approaches that were available there. Weather data and witnesses indicate that daylight conditions, low clouds and poor visibility prevailed, with cloud tops at 1,000 feet. After the second approach, the pilot radioed that he was heading back to the departure airport because he could not see the airport. No distress calls or unusual engine noises were heard. The airplane subsequently flew north of the airport and away from the departure airport at an altitude beneath the minimum radar coverage of 2,200 feet. It impacted the frozen Arctic Ocean in a right bank and at a 60-degree nose-down attitude about three miles away from the location of the pilot's last radio transmission. An examination of the airplane (before it sank through cracking ice) revealed no pre-impact mechanical malfunctions. An examination of the propeller revealed that it was under a power setting consistent with a maneuvering airspeed at the time of impact. An examination of the autopilot annunciator filament revealed that the autopilot was not engaged at impact. The airplane was nearly full of fuel and over its published maximum gross weight at impact. Small pieces of clear ice, about 1/4-inch thick, were found on portions of the tail surfaces. Interviews with operator employees and the pilot's wife revealed that the pilot may have felt pressure from himself and passengers to complete the flight.

The pilot of Cessna 207A, N800GA, was returning to his company base, passing about 2 miles north of a remote airstrip that was along the route of flight. The airstrip did not have any control tower. [Communications around an uncontrolled airport are conducted on a common traffic advisory frequency (CTAF)]. The pilot of a Short SC7, N451SA, announced his departure from the same airstrip on the CTAF, and took off in a northerly direction. He then began a climbing right turn toward the same destination as the Cessna 207A was proceeding. The two airplanes collided in mid-air, about 1.49 nautical miles east-northeast of the airstrip, which was about 18.3 miles west of their destination. They were observed spiraling downward from about 800 ft above the ground. Both airplanes were found lying flat and upright on a frozen lake, entangled together at the accident site. The Cessna's burned wreckage was lying on top of (and positioned toward the aft third of) the burned wreckage of the Short SC7.

The pilot of Cessna 207A, N800GA, was returning to his company base, passing about 2 miles north of a remote airstrip that was along the route of flight. The airstrip did not have any control tower. [Communications around an uncontrolled airport are conducted on a common traffic advisory frequency (CTAF)]. The pilot of a Short SC7, N451SA, announced his departure from the same airstrip on the CTAF, and took off in a northerly direction. He then began a climbing right turn toward the same destination as the Cessna 207A was proceeding. The two airplanes collided in mid-air, about 1.49 nautical miles east-northeast of the airstrip, which was about 18.3 miles west of their destination. They were observed spiraling downward from about 800 ft above the ground. Both airplanes were found lying flat and upright on a frozen lake, entangled together at the accident site. The Cessna's burned wreckage was lying on top of (and positioned toward the aft third of) the burned wreckage of the Short SC7.

The CFR Part 135 cargo flight departed at night on an IFR flight with a load of mining equipment. Route of flight was over remote/mountainous terrain. About 2 hours after takeoff, while cruising at 12,000' feet msl, the right engine and propeller began to overspeed. The captain feathered the #2 engine and declared an emergency. He began to divert to an alternate destination, about 120 miles away in an area of lower terrain, but the aircraft would not maintain altitude (single engine service ceiling, as loaded, was about 8,700 feet). The captain increased power to the left engine, but it began to produce banging and coughing noises. The captain elected to perform an emergency landing at a nearby, remote, military airfield (A/F). The A/F was located in mountainous terrain and had a one-way, daylight only approach. The captain lowered the gear and flaps, and began a visual approach while attempting to keep the runway end identifier lights (REIL) in view. The aircraft encountered severe turbulence, and the captain applied full throttle to the left engine in an attempt to climb. The REIL disappeared from view, and the aircraft collided with snow covered terrain about 2 miles west of the A/F. Ground personnel at the A/F reported high winds and blowing snow with limited visibility. Postcrash exam of the right engine revealed a loss of the propeller control system hydraulic oil. Flight at 12,000 feet was conducted without crew oxygen. The crew had exceeded their maximum allowable duty day without adequate crew rest.