History of Flight
On June 17, 2014, at about 1700 mountain daylight time, a Grumman G-21A airplane, N888GG, was destroyed when it impacted terrain and a postcrash fire ensued in the parking lot of the Lost Trail Powder Mountain Ski Area, about 13 miles south of Sula, Montana. The airplane was being operated as a visual flight rules (VFR) cross-country positioning flight under 14 CFR Part 91. Instrument meteorological conditions (IMC) were reported in the area, and the solo pilot received fatal injuries.
The flight departed Lemhi County Airport (KSMN), Salmon, Idaho, at about 1640, bound for Ravalli County Airport, Hamilton, Montana. According to the airplane owner, the airplane was being repositioned for the summer. It had arrived at Dillon Airport (KDLN), Dillon, Montana, on June 16 but was unable to continue to Hamilton due to weather. The pilot was told to remain in Dillon until the weather cleared. The pilot mentioned he might fly to Salmon the following morning and check the weather along the highway to Hamilton. The owner requested a telephone call before departure but did not receive one.
A witness at Dillon Airport reported that the pilot departed at about 0830 on June 17 but returned shortly due to weather. The airplane remained in Dillon until about 1630, when the pilot stated he would probably be back in 30 minutes and departed. A witness at Lemhi County Airport said the airplane stopped there before departing northbound along highway 93 toward Hamilton.
A witness living along highway 93 at about 4,000 feet elevation saw the airplane northbound toward the mountain pass in the direction of Hamilton. The witness, a pilot familiar with the route, noted that while the airplane was in VFR conditions under an overcast at about 6,500 feet, the pass was higher and appeared obscured. He observed a thunderstorm developing to the west and moving east toward the pass.
The highway 93 mountain pass is just over 7,000 feet in elevation. At the summit are a visitor center and the base of operations for a ski area, including a lodge and parking lot. An employee at the visitor center reported that the airplane arrived at a very low altitude, just above the trees, with snow and visibility about 1/4 mile. She saw the airplane "spin around" 6 to 7 times descending vertically before impacting the ground in the parking lot. Upon impact, the airplane burst into flames; initial responders were unable to approach due to intense heat.
Personnel Information
The pilot, age 62, held an airline transport pilot certificate with multiple ratings, including airplane single- and multi-engine land and sea, glider, rotorcraft, flight instructor, and instrument airplane. He held a first-class medical certificate issued January 7, 2014, with the limitation that he must wear corrective lenses. On that application, he indicated about 9,800 total flight hours, with 150 hours in the previous 6 months.
Aircraft Information
The Grumman G21-A, serial number N888GG, was manufactured in 1944 and equipped with two Pratt and Whitney R-985-AN-14B engines. No airframe or engine logbooks were found and are believed to have been consumed in the fire. The owner provided copies of maintenance records from the last maintenance facility. Both engines had been newly remanufactured and installed on June 6, 2013, at an airframe total time of 6,323.8 hours. An extensive annual inspection was completed on March 6, 2014, at 6,394.7 hours, with no major deficiencies noted. The last known maintenance, an oil change and minor adjustments, was completed on May 2, 2014, at 6,434.4 hours.
Meteorological Information
The accident site, at an elevation of about 7,000 feet, was located about 36 miles north of the departure airport and 39 miles south of the destination. Weather at the departure airport near the time of departure reported visibility 10 miles, calm wind, few clouds at 4,200 feet, broken at 6,500 feet, and overcast at 7,500 feet. A pilot witness on the ground along the route described the summit as obscured and reported a thunderstorm moving toward the pass. Witnesses at the accident location described overcast with ragged ceilings, visibility varying from better than one mile to obscured at the surface, and snow. A photograph taken shortly after impact showed visibility less than one-quarter mile in snow and an indefinite ceiling. No destination weather observations were available, but the trend was partly sunny in the morning becoming mostly cloudy in the afternoon. No record exists of the pilot receiving an official weather briefing.
Wreckage and Impact Information
The airplane impacted at the south end of the ski area parking lot, adjacent to a highway summit, rest area, and visitor center. Surrounding mountain peaks exceed 8,000 feet. Witnesses observed the airplane exit the base of overcast clouds in a flat spinning, vertical descent. The postcrash fire consumed the airplane. On June 18, 2014, the NTSB investigator-in-charge and an FAA air safety inspector examined the wreckage. Despite fire damage, the nose, tail, and wingtips were identifiable. The airplane appeared to have impacted in a level attitude with no evidence of forward, rearward, or sideways movement. All control surfaces were present; control continuity was established to the cockpit area but not to individual cockpit controls due to fire damage. The wing leading edge was straight and perpendicular to the fuselage centerline, and the lower fuselage frames showed upward crushing. Both engines were located appropriately. Five of six propeller blades were broken off at the hub; one blade remained attached to the right engine hub. All propeller blades showed extreme torsional twisting, tip curl, and S-bending. Exhaust manifolds on both engines exhibited plastic, hot metal folding and bending. No further engine examination was conducted.
Communications
No communications were heard from the accident airplane after departure from the uncontrolled airport, and no air traffic control services were requested.
Medical and Pathological Information
A postmortem examination attributed the pilot's cause of death to blunt force injuries. A toxicological examination found no anomalies.
Probable Cause
The investigation did not state a probable cause.