NTSB Factual Report

HISTORY OF FLIGHT

On July 4, 1995, approximately 1150 mountain daylight time, an Alon A-2 Aircoupe, N718RS, collided with trees while attempting to reverse course in a mountain canyon about 55 miles west of Cody, Wyoming. The private pilot, who was the sole occupant, received fatal injuries, and the aircraft was destroyed. The aircraft, which was part of a three ship personal pleasure flight, was being operated in visual meteorological conditions. The three aircraft departed Cody, Wyoming about 55 minutes earlier, and were en route to Butte, Montana. No flight plan had been filed, and the ELT was reported to have transmitted for about one minute after the impact.

According to the other pilots in the flight, all three aircraft were attempting to fly over Sylvan Pass, about 10 miles west of the east gate of Yellowstone National Park. As they approached the pass, the lead aircraft began to lose altitude in the downdrafts they were beginning to encounter on the leeward side of the pass. The first two aircraft were in the process of reversing course when the lead aircraft impacted the trees.

The pilot of the aircraft immediately in trail behind the accident aircraft stated that N718RS had turned to follow the road toward the pass. At that time, he lost sight of the aircraft. The third aircraft was about 1 to 2 miles in trail behind the second aircraft. The pilot of the second aircraft noted that terrain in the area was rising rapidly and he checked his altitude at about 8500 to 8600 feet. The accident aircraft was at about the same altitude, but was appearing to descend at a fairly rapid rate. From his position, it appeared that the accident aircraft was losing a safe margin above the terrain and he called over the radio for the pilot to turn around. The pilot of the second aircraft stated that "I saw his plane appear to enter a high angle of attack as a lot of the upper wing surface became visible. About the same time, [the pilot] transmitted in a stressed voice 'I can't get it up.' Seconds later I saw the left wing drop as if entering a left turn, which is the way he should be turning to exit the area."

The pilot of the second aircraft did not see the impact, but spotted smoke, and heard the ELT for about a minute.

WRECKAGE AND IMPACT INFORMATION

The wreckage was found in coniferous trees, inverted, with the fuselage centerline axis on a magnetic heading of 220 degrees. The left wing was positioned on top of a felled 100 foot tree, which had its axis oriented with its top on a heading of 150 degrees. The empennage was separated and was a few feet from the fuselage.

The cabin area was burned, and the inboard sections of the main spars were melted away. The left aileron push tube was intact to the aileron, but was separated in the cabin. The right aileron push tube was intact to the aileron attach point, but the aileron was melted near the attach point. Elevator cables had continuity from the cabin to the elevator. The rudder cables had continuity from the aft cabin area to the rudders. All elevator, aileron and rudder hinges were intact. The elevator trim tab was bound in a full up position.

One propeller blade was bent aft 60 degrees about ten inches from the hub, with spanwise scars. The second propeller blade was straight to the outboard ten inches, which was bent aft about 20 degrees, and was twisted with S curving and light chordwise scratching. Both propeller blades exhibited twisting.

Oil was found in the engine. The spark plugs appeared serviceable. Both magnetos were melted and did not spark. The crankshaft was rotatable, and full valve train continuity was established.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was conducted on the pilot at West Park Hospital Morgue, Cody, Wyoming on July 5, 1995, by Dr. Lee K. Hermann. Toxicological testing was conducted by the Armed Forces Institute of Pathology, with negative results.

ADDITIONAL DATA/INFORMATION

The wreckage was released to the Lake District Ranger on July 5, 1995, while it remained on site.

NTSB Probable Cause

THE PILOT'S FAILURE TO MAINTAIN CLEARANCE FROM TERRAIN WHILE MANEUVERING TO REVERSE COURSE. A FACTOR WAS THE DOWNDRAFTS ENCOUNTERED IN THE MOUNTAINOUS TERRAIN.