History of Flight
On August 1, 2008, at approximately 1433 Pacific daylight time, an amateur-built experimental Long Lancair ES, registration N45EL, disappeared from radar and lost radio contact 40 nautical miles northwest of Yakima, Washington. The aircraft wreckage was located 9 nautical miles northwest of Cliffdell, Washington, at a terrain elevation of 3,830 feet. The private pilot and single passenger were killed, and the airplane was destroyed. Visual meteorological conditions prevailed, and an instrument flight rules (IFR) flight plan had been filed. The flight originated at Ketchikan, Alaska, about 0957 Alaska daylight time, destined for Mountain Home, Idaho.
The pilot received a standard weather brief from the Juneau Automated Flight Service Station at 0608 Alaska daylight time and filed an IFR flight plan. Departure was released at 0954 Alaska daylight time. En route, the pilot received normal services from Anchorage Air Route Traffic Control Center and Seattle Terminal Radar Approach Control. At 1422 PDT, the pilot checked in with Seattle ARTCC at 11,000 feet mean sea level, cleared direct to Yakima. At 1432 PDT, he confirmed his altimeter setting (29.87 inches of mercury), which was his last transmission. At 1433 PDT, an altitude deviation to 9,700 feet was noted, and radar and radio contact were lost. Repeated attempts to contact the aircraft were unsuccessful.
Personnel Information
The pilot, age 68, held a private pilot certificate with an instrument airplane rating, issued December 9, 2001. He held a third-class medical certificate issued in May 2008, with a limitation requiring corrective lenses for distant and near vision. His logbook indicated a total flight time of 592.7 hours, including 176 hours of simulated instrument time and 4 hours of actual instrument time. In the previous 30 days, he had logged 10.8 hours, all in the accident aircraft, and a total of 266.2 hours in the accident airplane. His most recent flight review was on May 14, 2008, and his instrument proficiency check was dated July 9, 2008.
Aircraft Information
The four-seat, single-engine, low-wing, fixed-gear experimental category aircraft was constructed by the pilot and issued an airworthiness certificate on September 12, 2004. It was powered by a Teledyne Continental IO-550 engine and equipped with an Aero Composites three-bladed propeller. The most recent annual inspection was completed on April 5, 2008, and the last oil change was on July 14, 2008, at a total time of 267.2 hours.
Meteorological Conditions
At the time of the accident, a low-pressure system was over southeastern British Columbia, with a cold front extending southwestward through Washington and Oregon. The accident site was behind the cold front. Stations to the west and southwest reported light to heavy rain showers with overcast skies. The closest station, Stampede Pass (13 miles northwest), reported at 1423 PDT: wind from 290 degrees at 9 knots, visibility 10 miles, scattered clouds at 800 feet, overcast ceiling at 1,500 feet, temperature 11°C, dew point 8°C, altimeter 30.01 inHg. Bowers Field (28 miles east) reported at 1453 PDT: wind from 310 degrees at 9 knots, visibility 10 miles, few clouds at 7,500 feet, scattered at 9,000 feet, temperature 25°C, dew point 9°C, altimeter 29.89 inHg.
Upper wind data indicated surface winds from the southwest at 13 knots, increasing to 25 knots at 4,800 feet, and exceeding 50 knots above 18,000 feet. At 11,000 feet (the aircraft's cruising altitude), wind was from 245 degrees at 27 knots with a temperature of -1°C. The sounding indicated a chance of light to moderate turbulence. The wind profile was also favorable for mountain wave development; rawinsonde data identified a wave near 10,113 feet with potentially moderate-to-severe turbulence.
Reflectivity data from the KATX WSR-88D radar at 1431 PDT showed an area of very light to light intensity echoes extending from Mount Rainier east-northeast through the accident site. The aircraft was observed encountering this band of echoes and making a right turn before the upset. Photos taken by the occupants minutes before the incident show a broken to overcast cloud layer and a band of higher clouds downwind from Mount Rainier with signs of undulation, consistent with mountain wave activity.
Flight Path and Wreckage
Radar data showed the airplane on a steady southeast course at 11,000 feet msl. At 1431:30, the track began a descending right-hand turn. The final radar return was at 1432:06 at 9,700 feet msl. The wreckage was found about 1 mile west of the final radar return, at a terrain elevation of 3,830 feet. The debris field consisted of individual parts—left wing, right wing, horizontal stabilizer, fuselage, and engine—distributed over 0.5 miles on a densely wooded mountain slope. No initial point of impact was identified.
Data from the primary flight display showed that approximately 5 minutes 36 seconds before the end of recording, at 11,000 feet, the airplane experienced continuous turbulence with vertical g loads from 0.77 to 1.5. About 1 minute before the end, the airplane entered a right turn with about 30 degrees of bank and a 600–900 feet-per-minute rate of descent. Approximately 25 seconds before the end, at 10,500 feet, the bank angle increased past 30 degrees to about 100 degrees, the rate of descent increased to 11,500 feet per minute, and airspeed increased from 150 to 280 knots, while the average g-load remained about 1.1. In the last 6 seconds, g-loads increased to 4.8. The last data point indicated the airplane at 6,135 feet msl, 88.6 degrees nose down, 113 degrees angle of bank, and 290 knots. Engine rpm and fuel flow remained steady throughout.
Elevator Control Examination
While moving the wreckage, the recovery contractor noted an unusual condition on the elevator control rod. The rod end bearing connecting to the elevator torque tube behind the cockpit seats had a lock nut positioned so that only 2–3 threads were exposed. The anodized aluminum threads showed wear on the first 2–3 threads, with subsequent threads unworn. At the opposite end of the push rod, the rod end bearing was screwed all the way in, with the lock nut against the shoulder. The Lancair ES builder's guide specifies that the rod end bearings should be threaded in until the bearing hole is 2 7/16 inches from the push rod tube end, which would expose most of the threads. Examination of drawings indicated that aft movement of the cockpit control would deflect the elevator up (nose up), imparting a compressive load on the push rod.