SEA96FA061

Shortly after reaching a cruising altitude of 9,500 feet, the aircraft's course was observed on radar to change from southeasterly to southwesterly. Its average ground speed decreased from 170 knots to 108 knots during this track change. The pilot called ATC with his call sign, and about five seconds later, an unintelligible, one-second-long transmission was heard. At that same time, radar information showed the aircraft at 8,800 feet. Radar and radio contact were lost shortly thereafter. Three days later, wreckage was found where the aircraft had crashed. The crash site was 1,820 feet above sea level and 1/2 mile south-southwest of its last observed radar position; the aircraft's average descent angle from the 8,800-foot-altitude position to the crash site was about 51 degrees. The aircraft was extensively damaged during impact. No damage was noted on tall trees that surrounded the accident site. Also, no preimpact mechanical malfunction or failure of the aircraft or engines was found, and no pre-accident impairment of the pilot was found.

History of flight

On February 16, 1996, approximately 0746 Pacific standard time, a Cessna 402B, N5198J, operated by Sports Air Travel, Inc. of Troutdale, Oregon (d/b/a West Coast Air Cargo) as West Coast flight 1420 (WCC1420), was lost from radio and radar contact with Seattle Air Route Traffic Control Center (ARTCC) while on a 14 CFR 135 non-scheduled domestic cargo flight from Troutdale to Redmond, Oregon. The wreckage of N5198J was found 27 nautical miles southeast of the Troutdale airport, in the Mt. Hood National Forest southeast of Estacada, Oregon, on February 19. The aircraft was destroyed and the airline transport pilot, who was the airplane's sole occupant, was fatally injured. Visual meteorological conditions had been forecast for the accident area, and were reported at Troutdale, at the time of the accident. The airplane was on a visual flight rules (VFR) flight plan.

According to the FAA's air traffic control (ATC) record of the accident, the aircraft departed Troutdale at 0735 and checked on to the Seattle ARTCC sector 5 frequency at 0740, reporting out of 5,800 feet for a final altitude of 9,500 feet. After the controller acknowledged this transmission, there were no further communications between WCC1420 and ATC for the next six minutes. During this time, Seattle ARTCC radar tracked the aircraft in a steady climb to 9,500 feet on a southeasterly course toward Redmond. According to National Track Analysis Program (NTAP) radar data provided by Seattle ARTCC, the aircraft reached 9,500 feet at 0745:38 and continued southeast for the next 24 seconds. The aircraft's track symbol changed from a secondary return to a correlated primary return (no altitude reported) at 0746:02.

At 0746:09, the pilot radioed to Seattle ARTCC, "seattle [sic] westcoast uh fourteen twenty." The controller told the pilot to go ahead. At 0746:14, an unintelligible transmission of approximately one second's duration was recorded. At the same time (0746:14), a secondary return was observed from the aircraft, at 8,800 feet, about 1/2 mile southwest of the 1546:02 correlated primary return. Based on the straight-line distance and time between NTAP radar positions, the plot-to-plot average ground speed decreased from 170 knots, between 0745:50 and 0746:02, to 108 knots between 0746:02 and 0746:14. The aircraft's gear-up/flaps-up, zero bank angle, idle power stall speed at 6,300 pounds gross weight, according to the Cessna 402B owner's manual, is 83 knots calibrated airspeed (KCAS) and its single-engine minimum control speed (Vmc) is also 83 KCAS. (NOTE: 83 KCAS corresponds to a true airspeed of 96 knots in standard atmospheric conditions at 9,500 feet). The aircraft's last NTAP radar position was a correlated primary return (no altitude reported) at 0746:26, about 1 mile west of the 0746:14 return. There was no further communication with WCC1420.

The Seattle ARTCC controller subsequently attempted to re-establish radio contact with WCC1420 using several airborne aircraft in the vicinity as radio relays, all without success. He also asked these aircraft to listen for an emergency locator transmitter (ELT) signal on 121.5 MHz, again with negative results. A search was then initiated, but the aircraft wreckage was not located until February 19th. The crash site was 1,820 feet above sea level and was about 1/2 nautical mile south-southwest of the 0746:26 final NTAP radar position. Based on the straight-line, point-to-point horizontal distance traveled versus altitude lost from the 0746:14 radar position to the crash site, the average descent angle from that position to the crash site was calculated to be 50.9 degrees from the horizontal.

The accident occurred during the hours of daylight at 45 degrees 11.0 minutes North and 122 degrees 3.1 minutes West.

Personnel information

According to company training records, the pilot received his initial 14 CFR 135 training from Sports Air on the Cessna 310 aircraft on January 8, 1992. His most recent 14 CFR 135 pilot proficiency check was three days before the accident, in a Cessna 402. The check was satisfactory, with satisfactory performance of steep turns, approaches to stalls, specific flight characteristics, powerplant failure, and instrument procedures among the flight maneuvers documented as being evaluated. According to copies of the pilot's payroll records furnished by the operator, the pilot was on the last duty day of a 5-day on/2-day off duty cycle, and had logged 11 hours of rest (from 1945 to 0645) prior to starting duty at 0645 on the day of the accident. The pilot logged 13 hours of duty (0645 to 1945), with 11 hours rest, during each of the previous four days.

Aircraft information

The aircraft, a 1975 model, had been operated by Sports Air for approximately the past 10 years. Based on total time at the aircraft's last inspection (as recorded in the aircraft logbook) and hours reported flown by the operator since this inspection, the aircraft had approximately 10,024 hours total time at the time of the accident. Recent major maintenance actions documented in the aircraft logbook included removal and replacement of the right propeller four days before the accident, and removal and replacement of the vertical tail the previous December. Sports Air and its FAA principal maintenance inspector (PMI) also stated that certain elements of Cessna's Model 400 Series Piston Engine Aircraft Continued Airworthiness Program (Cessna document number D5305-2-13), which recommended additional inspections for the accident aircraft, had been incorporated by the FAA PMI into Sports Air's FAA-approved maintenance requirements.

According to the engine logbooks, the right engine, a Continental TSIO-520-E, had 1,836.1 hours since major overhaul at its last inspection, a 100-hour inspection on February 9, 1996. The manufacturer's recommended time between overhauls (TBO) for the engine is 1,400 hours. Sports Air and its FAA principal maintenance inspector (PMI) both stated that Sports Air was operating the engines with an FAA-authorized TBO extension to 2,000 hours, subject to additional maintenance and inspection requirements including engine oil samples at 50-hour intervals. Since June 1994, all six right engine cylinders had, at various times, been documented as being removed and replaced for low compression, cracks, or bad exhaust valves.

According to the operator, the aircraft departed Troutdale with 100 gallons of fuel in the main tanks, 63 gallons of fuel in the auxiliary tanks, 250 pounds of cargo in cargo area A, 150 pounds of cargo in cargo area B, 125 pounds of cargo in cargo area C, and 25 pounds of cargo in cargo bay B. The cargo consisted primarily of bank documents such as canceled checks. The takeoff gross weight reported by the operator was 5,973 pounds. The aircraft's maximum takeoff gross weight is 6,300 pounds. Based on the loading reported by the operator, the aircraft center of gravity was computed at 157.25 inches aft of datum, with an acceptable range of 149.9 to 160.1 inches.

Meteorological information

The 0746 Troutdale surface observation reported scattered clouds at 10,000, 15,000, and 25,000 feet with 40 miles visibility. The operator reported that the pilot obtained a weather briefing via company DUATS prior to departure.

Wreckage

The aircraft wreckage was examined at the accident site on May 1, 1996. The accident site was located near the bottom of an approximately 700-foot-deep river gorge, on steeply sloping terrain in a remote, heavily wooded wilderness area. The slope at the top of the wreckage area was measured at 37 degrees. The top of the accident area was at an elevation of approximately 1,820 feet above sea level, with the bottom being at approximately 1,720 feet elevation. The wreckage area was on a northwest facing slope, just east of the confluence of the Roaring River and the South Fork of the Roaring River.