SEA99LA081

The airplane went missing on a flight from the airport where an amphibious float installation had just been performed. Its wreckage was located several hours after departure at the 6,100-foot level on a snow-covered ridge in a National Forest wilderness area, 11 nautical miles from the departure airport. The pilot was found dead at the accident scene. Recovery personnel reported that the airplane appeared to have struck trees and impacted going down a 32-degree slope, where it impacted a tree stump in a depression. The recovery crew also reported that all aircraft components were found within about 20 feet of the main wreckage, that there was no evidence of fire, that search-and-rescue personnel (the first persons to reach the site) had reported a strong fuel smell, and that the airplane had good flight control continuity 'as best as could be determined.' Post-accident examinations of the airplane's engine and fuel injection servo disclosed evidence of non-compliance with various FAA Airworthiness Directives and manufacturer's service bulletins, but no clear evidence of any mechanical anomalies or malfunctions. Visual meteorological conditions were reported at a weather observation station 59 nautical miles away from the site during the accident time frame.

On June 6, 1999, between 0830 and 0900 mountain daylight time, an amateur-built D. Wayne Smith Wayncraft 14 experimental-category airplane, N58WS, departed Libby, Montana. Later that morning (approximately 1125), search and rescue satellites detected emergency locator transmitter (ELT) signals originating in the Libby area, and a search was initiated to locate the source of the ELT signals. The substantially damaged wreckage of N58WS was located near the computed signal origin between approximately 1600 and 1630 that afternoon. The wreckage was located at approximately the 6,100-foot level on a ridge in the Cabinet Mountain Wilderness area of the Kootenai National Forest, approximately 11 nautical miles west of the Libby airport. The private pilot-in-command, who was the registered owner (but not the builder) and sole occupant of the aircraft, was found dead with the wreckage. Visual meteorological conditions were reported at Glacier Park International Airport, Kalispell, Montana (approximately 59 nautical miles east of the accident site), during the entire time between N58WS's departure from Libby and the time the wreckage was located, and no flight plan had been filed for the 14 CFR 91 personal flight.

The Wayncraft 14 is a replica of the Piper PA-14 airplane built from plans prepared by Wag-Aero Inc., Lyons, Wisconsin (Wag-Aero's model name for this plans-built aircraft type is the "Sportsman 2+2".) According to FAA records, the accident aircraft received an experimental-category airworthiness certificate on July 22, 1990, and was sold to the accident pilot by its builder in January 1999. The aircraft logs, and tachometer hour reading observed in the aircraft wreckage, indicated that the aircraft's last condition inspection was performed by the aircraft's builder on January 5, 1999 (approximately 33 flight hours prior to the accident), and that the aircraft had approximately 177 total airframe hours at the time of the accident.

The accident pilot had had the airplane modified by installation of Montana Float model 2300A amphibious floats (the float installation was performed by the Montana Float Company, Inc., of Libby.) An FAA letter of authorization had been issued for this modification. The aircraft log entry documenting the float installation and post-modification flight testing required by the FAA letter of authorization was dated June 5, 1999, the day prior to the accident. According to the Montana Float Company work order for the float installation, the pilot installed an electric hydraulic pump and a hand pump in conjunction with the float installation. According to the aircraft logs, the float installation increased the aircraft's empty weight from 1,318 pounds to 1,618 pounds and moved its empty center of gravity forward by 1.56 inches, from 13.76 inches aft of datum (datum is the leading edge of the wing) to 12.2 inches aft of datum (the aircraft's allowable center of gravity range is 9 to 21 inches aft of datum, according to Wag-Aero's plans.) (NOTE: A copy of the old aircraft weight and balance computation furnished by Montana Float company indicated that the accident pilot had performed the empty weight and balance computation himself.) The aircraft's maximum gross weight was listed in the aircraft logs as 2,200 pounds, and is given in Wag-Aero's plans as 2,250 pounds for a seaplane variant.

The aircraft logs, and the Montana Float Company work order for the modification, indicated that following the float installation, the aircraft was test-flown by the accident pilot for a total of 2 hours and 12 minutes, including 5 wheel landings and 11 water landings, and that the pilot had reported good controllability. A difference of 2.6 hours was noted between the aircraft hours recorded on the Montana Float Company work order for the float installation (dated on the day of the accident) and the tachometer reading noted in the aircraft wreckage.

The airplane was equipped with a 200-horsepower Textron Lycoming IO-360-A1B engine (Wag-Aero's plans state that the aircraft is approved for engines of 115 to 200 horsepower, and list the recommended engines for the aircraft as Textron Lycoming O-290 series, O-320 series, and O-360 series) and Hartzell 2-blade constant-speed propeller. The aircraft and engine logs, and tachometer hours observed in the aircraft wreckage, indicated that the engine, manufactured in 1971, had 1,510 total hours at the time of the accident. Prior to being installed on N58WS, the engine was involved in two propeller strikes, the first in 1980 at 1,237.34 engine hours and the second in 1988 at approximately 1,335 engine hours. The engine was installed on N58WS following repairs made to the engine after the 1988 propeller strike. These repairs included replacement of the crankcase, crankshaft, and connecting rods with "repaired overhauled parts." Although the engine log indicated that the engine was disassembled, examined, repaired and reassembled following both propeller strikes, there was no record that the engine had ever undergone a major overhaul. Textron Lycoming service instructions list the recommended time between overhauls (TBO) interval for the accident engine serial number (L-7396-51A) as 1,400 hours, or in the 12th year for engines which do not accumulate the recommended TBO flight hours prior to that time.

The 63-year-old pilot, who was listed in the FAA airman registry as being from Redding, California, held a private pilot certificate with airplane single-engine land, airplane single-engine sea, instrument airplane, and helicopter ratings. He held a third-class medical certificate with a date of issue of June 15, 1997. The FAA reported that the pilot stated he was on a cholesterol-lowering medication at the time of his last FAA medical examination. FAA records indicated that the pilot held repairman/experimental aircraft builder certificates for eight different experimental aircraft types, but did not hold one for the accident aircraft; he also did not hold an FAA mechanic certificate.

The 0856 automated weather observation at Glacier Park International (elevation 2,972 feet above sea level) reported conditions as follows: wind from 250 degrees at 10 knots; visibility 10 statute miles; ceiling 5,500 feet overcast; temperature 11 degrees C; dewpoint minus 2 degrees C; and altimeter setting 29.96 inches Hg.

The aircraft impacted a wooded and snow-covered ridge. Personnel who recovered the aircraft from the accident site reported the following, based upon their observations at the accident site:

The [aircraft] was traveling down slope upon impact. The slope was 32 degrees. At 162 feet before impact, the aircraft clipped a tree approximately 60 feet above ground. It continued for another 110 feet and hit a snag approximately 20 feet high. It continued on for 52 feet more where it impacted in a slight depression in the ridge, facing down slope. The [aircraft] came to rest against a snag stump approximately 24 inches in diameter and protruding approximately 5 feet above the snow level.... The marks from the floats indicate about 4 feet of [forward] travel from initial impact to stop. The right side of the aircraft just [forward] of the right windshield post and door frame impacted the stump....

The right wing was noted to be shattered; however, all aircraft components were found at the site within approximately 20 feet of the main wreckage. The recovery crew reported that they found good continuity to the aircraft's flight controls "as best as could be determined", and that both fuel tanks were found ruptured and empty; however, they reported that search-and-rescue (SAR) personnel who were the first personnel at the accident site stated they could smell fuel when they arrived on scene (approximately 1700 on the day of the accident.) The recovery crew reported that there was no evidence of pos