SEA98FA179

A flight instructor, who checked the airplane out to the pilot for the night flight, reported that the pilot stated that he was going to stay in the local area (Canada) for a sight-seeing flight with a friend. When the aircraft did not return at the proposed time, a search was initiated. The aircraft was found the next morning, 17 miles south of the Canadian/U.S. border in a deep, narrow canyon located in the mountains of a wilderness area. The wreckage was found partially submerged in a river. The wreckage was positioned in a nearly vertical nose down attitude. Rearward crushing was noted to the entire length of the leading edges of both wings. During the post-accident investigation, no evidence was found to indicate a mechanical failure or malfunction.

History of flight

On September 15, 1998, about 2130 Pacific daylight time, a Cessna 172M, C-FZEY, operated by Aspen Air Ltd as a 14 CFR Part 91 personal flight, collided with the terrain in a valley surrounded by mountains located about 13 miles northwest of Concrete, Washington. Visual meteorological conditions prevailed at the time and no flight plan was filed. The aircraft was substantially damaged and the private pilot and his passenger were fatally injured. The flight had departed from Langley, B.C. about 2030.

A flight instructor from Aspen Air reported that he had flown this aircraft three times that day, with the last flight ending at 1832. The pilot checked the airplane out about 2000. The flight instructor stated that everything on the airplane was operable during the flights. While the pilot was completing the check-out paper work, he indicated to the instructor that the purpose of the flight was to take a friend out for a sight-seeing flight in the local area. The pilot indicated that the route of flight was from Langley to Abbottsford, B.C., then to Chilliwack, B.C. and a proposed return to Langley about 2200 to 2230. The flight instructor also told the pilot that the aircraft needed to be refueled as it only had about one hour's flight time remaining. The flight instructor and the pilot completed the necessary paperwork, and the pilot indicated that he had to go and pickup his passenger. The flight instructor did not see the pilot after this time. When the flight did not return at the expected time, the flight instructor reported the aircraft overdue.

The flight instructor stated that as far as he knew, he did not think that the pilot had ever flown into the United States before, but thought that the pilot knew of the procedures for flight into the United States from Canada.

The wreckage was located approximately 17 miles south of the Canadian border at the southwest corner of Mount Baker in Washington, on September 16, 1998, at 0830. Relatives reported that the pilot and passenger had been discussing a sight-seeing flight around the Mount Baker area for about three weeks prior to the accident.

Personnel information

At the time of the accident, the pilot held a private pilot certificate for single-engine land and sea aircraft. The pilot's flight logbook indicates that a total flight time of 191 hours had been accumulated in all types of aircraft. Approximately 180 hours had been accumulated in the Cessna 172. Approximately 15 hours total time had been accumulated during night time conditions.

Communications

The manager of the Langley Airport tower reported that for the night of the accident, there was no record of communication from the subject aircraft on the 24-hour tower audio tapes which monitor the Langley radio frequencies normally used by arriving and departing aircraft. The manager reported that there was record of other aircraft communications on the tapes around the time of 2000 to 2230.

The Canadian Flight Supplement (CFS) requires that all aircraft communicate with Langley Tower (119.0), and Langley Ground (121.9), during the hours of 1600 to 0130 UTC. Outside of these hours, communicate/broadcast on a Mandatory Frequency (MF) of 119.0, when within three nautical miles and 1,900 feet above sea level of Langley. The CFS is provided free of charge to all licensed pilots in Canada.

Canadian aviation officials reported that there was no record that the pilot received a weather briefing or that he filed a flight plan. The United States Federal Aviation Administration reported that there was no record of communication with the subject aircraft while in the United States.

Wreckage and impact information

The airplane came to rest on the shore of a rocky riverbed in the middle of a deep, narrow canyon located at the southwest corner of Mount Baker, in the Mount Baker Wilderness Area. A dirt Forest Service road that ran through the canyon was within about 400 feet of the accident site. No houses, buildings or lighted structures were in the area. The accident site elevation was approximately 1,000 feet. The right wing and lower engine assembly were partially submerged in the river, with the remaining aircraft in shallow water on the rocky shore. The surrounding terrain consisted of thick vegetation and tall evergreen trees that enclose the river area. The river was about 30 feet wide with rising terrain on each side. The wreckage distribution was oriented on a magnetic heading of approximately 260 degrees. The initial ground impact point was located on the dry shore of the riverbed, approximately 45 feet east of the main wreckage on an approximate 80 degree magnetic heading. Impact marks and paint transfer were noted on the rocks between the wreckage and the initial ground impact point, where fragments of the left wing-tip red lens case position light were found.

The airplane cabin was found upright, in a near-vertical nose down attitude. The empennage was bent and broken over to the right about 80 degrees. The right side horizontal stabilizer and the vertical stabilizer were in the water. The structure broke at the rear baggage bulkhead. The horizontal and vertical stabilizers remained attached, with the elevator and rudder attached at their respective hinges. The nose section and forward cabin area were crushed and displaced rearward along the airplane's longitudinal axis. The roof of the cabin and wing structure was pushed forward over the engine. Control system continuity was established from the tail section to the cockpit.

The propeller assembly remained attached to the engine crankshaft. The propeller flange was bent approximately 35 degrees. The propeller spinner was crushed rearward and flattened. Propeller blade "A" was bent aft approximately 90 degrees near the blade tip. About two inches of the blade tip had been torn away. Deep leading-edge gouges were noted, along with chordwise striations on the blade back.

Propeller blade "B" was curled forward about 70 degrees at the mid-section. About three inches of the blade tip were bent aft approximately 90 degrees. Deep leading-edge gouges were noted, along with severe chordwise striations on the blade back.

The left wing remained attached at the root. The inboard section of the leading edge was torn and displayed rearward crushing. The remaining length of the leading edge displayed rearward crushing. The outboard four feet of the wing tip were shredded and bent upward approximately 45 degrees. Buckling was noted along the wing structure, and the left fuel tank was compromised. The flap was retracted and remained attached at its respective hinges. The left aileron was attached at two hinges and was broken downward at the outboard hinge. The left-side lift strut remained attached at the wing fitting, and partially attached at the fuselage fitting. Severe fuselage crushing deformation was noted in this area. The strut was bent about 90 degrees, approximately one foot outboard of the fuselage attach point. Control continuity was established to the cockpit area.

After the wreckage was recovered from the accident site, the right wing, which was under water at the accident site, was inspected. The wing remained attached at the root. The entire length of the leading edge was crushed aft. Buckling was noted along the wing structure. The right fuel tank was compromised. The flap and aileron remained attached to their respective hinges. The flap was retracted. The right side lift strut remained attached at the wing fitting and partially attached to the fuselage fitting. Severe fuselage crushing deformation was noted in this area. Control system continuity was established to the cockpit area.

After the wreckage was recovered from the accident site, the engine was inspected. The crankshaft was limited to approximately 30 degrees rotation due to the bent propeller flang