History of Flight
On July 18, 2011, at 1746 mountain daylight time, a Mooney M20C, registration N6855N, impacted terrain while on approach to Simpson Airport (ID62) in Grace, Idaho. The pilot/owner operated the airplane under 14 CFR Part 91 as a personal cross-country flight. The private pilot and two passengers were fatally injured; the airplane sustained substantial damage. Visual meteorological conditions prevailed for the flight, which departed Afton, Wyoming. No flight plan was filed.
Witnesses traveling south on Highway 34 reported seeing the airplane fly overhead, make a slight right bank, then bank left toward the runway. They heard the engine with no unusual sounds and observed the landing gear in the up position. The airplane appeared to be in a 45-degree left bank as it turned toward the runway, with the top of the fuselage and wings fully visible. The witnesses then saw the airplane drop behind sagebrush, followed by a cloud of smoke. They called 911 and responded to the site. Weather was reported as clear with no wind.
Personnel Information
The 46-year-old pilot held a private pilot certificate with an airplane single-engine land rating and a third-class FAA medical certificate issued on May 16, 2011, with no waivers or limitations. His logbook showed the last entry on April 28, 2011, with three flights totaling 1.3 hours. As of that date, his total flight time was 563 hours, with 303 hours in the accident airplane. On his medical application dated May 16, 2011, he reported 600 total hours and 100 hours in the preceding 6 months. Investigators could not determine when his last flight review was completed.
Aircraft Information
The 1968 Mooney M20C, serial number 68138, was equipped with a Textron Lycoming IO-360-B1B engine and a Hartzell propeller. Maintenance logbooks recorded the last annual and engine 100-hour inspection on February 3, 2011, with a total airframe time of 5,334.62 hours and engine time since major overhaul of 721.2 hours. According to the manufacturer, at a gross weight of 2,575 pounds with power off, flaps and gear up, and a 40-degree bank, the stall speed would be 68 knots.
Meteorological Information
The closest official weather observation station was at Pocatello Regional Airport (PIH), 42 nautical miles northwest of the accident site. A METAR issued at 1653 reported winds from 200 degrees at 11 knots gusting to 22 knots, visibility 10 statute miles, scattered clouds at 11,000 feet, temperature 36°C, dew point 07°C, and altimeter 29.99 inches of mercury. A later METAR at 1753 reported winds from 160 degrees at 13 knots gusting to 20 knots, visibility 10 statute miles, scattered clouds at 11,000 feet, temperature 34°C, dew point 10°C, and altimeter 29.97 inches of mercury. Weather from Allen H. Tigert Airport in Soda Springs, Idaho, about 7 miles northeast of the accident airport, indicated a density altitude of 8,976 feet.
Airport Information
Simpson Airport (ID62) in Grace, Idaho, was privately owned and not listed in the FAA Airport/Facility Directory. The airport elevation was 5,598 feet, with runways on headings 16 and 34, composed of gravel. No segmented circle or windsock was present. The designated traffic pattern used left turns. An obstacle—a 4-foot fence—was located about 200 feet from the runway and 90 feet left of the centerline for runway 34.
Wreckage and Impact Information
The NTSB investigator-in-charge, an FAA airworthiness inspector, and a Lycoming representative examined the wreckage the day after the accident. No mechanical anomalies that would have precluded normal operation were identified. The wreckage was strewn along a 200-foot debris path on a northwesterly heading. The first identified point of impact (FIPC) contained red lens fragments. Approximately 75 feet from the FIPC was a round flat area with a cut mark. The main wreckage came to rest upright facing northeast, about 1,145 feet south of the airport. Both wings remained attached; the bottom of the left wing was ripped open, and the right wing had leading- to trailing-edge crush damage. The aft fuselage and empennage separated; the rudder was found next to the tail section. The engine separated from its mounts but remained attached via wiring. Manual rotation of the crankshaft established continuity, and thumb compression was obtained on all cylinders. The left magneto sustained internal damage; the right magneto produced spark when rotated. Top spark plugs showed normal operation signatures. The propeller blades were bent aft with chordwise scratching; one blade exhibited s-bending and partial tip separation.
Medical and Pathological Information
An autopsy of the pilot performed on July 19, 2011, listed blunt force trauma as the cause of death. Toxicological testing of the pilot's specimens contained no findings of drugs or volatiles; tests for carbon monoxide and cyanide were not performed.
Tests and Research
The left magneto was examined on August 8, 2011. Damage to the mounting lug and ring was noted, with the lug displaced about 1/8 inch. Binding was observed during manual rotation but resolved after loosening case mounting screws; sparks were observed at all posts. Internal disassembly revealed no damage, thermal distress, or arcing. The Garmin GPS unit, damaged by impact, was repaired and data downloaded. The data included two tracklogs for the accident day, with the accident flight starting at 1720:42 from AFO airport. The final GPS fix at 1746:21 corresponded to the accident area, showing a groundspeed of 79 knots and a course of 002 degrees true north. The plot indicated that the airplane crossed the extended runway centerline, then made a sharp left turn toward the extended centerline.