History of Flight
On July 18, 2016, at approximately 2007 eastern daylight time, an Aeronca 11AC, registration N85893, was destroyed when it impacted terrain after a loss of engine power while in the traffic pattern of a private grass airstrip near Ishpeming, Michigan. The pilot and the pilot-rated passenger sustained fatal injuries. The aircraft was operated as a personal flight under 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed. The local flight had departed Edward F. Johnson Airport (M61) at about 1945.
According to the pilot's daughter, she owned the airplane and stated that her father was the pilot. She had purchased it from the pilot-rated passenger in June 2015 and was in the process of selling it.
A witness observed the airplane make a low pass over the grass airstrip. During the left crosswind turn, the airplane appeared "mushy" and seemed to "plow through the turn." The witness did not see the impact but heard it. After arriving at the site, the airplane's tail was elevated, later lowering when access to the cabin was attempted.
Another witness, located about 800 feet west of the approach end, saw the airplane approach from the southeast with normal engine sound and flight path. After a low pass over the northeast runway, it turned left crosswind, entering a close-in left downwind at an estimated altitude of 100 to 150 feet above ground. The airspeed seemed slower than normal. The witness then heard a change in engine noise and saw the airplane in a left bank when the engine stopped. The airplane entered a left spiral, turned about 360 degrees, and impacted the ground.
Personnel Information
The pilot, aged 49, occupied the right seat. He held a private pilot certificate with a single-engine land rating and was a certified flight instructor with a sport endorsement for single-engine land airplanes. He possessed a third-class medical certificate dated April 4, 2016, with a limitation requiring glasses for near and intermediate vision. He reported 750 total flight hours at the time of his medical examination.
The passenger, aged 48, occupied the left seat. He held a sport pilot certificate with a single-engine land rating and did not hold a medical certificate.
Aircraft Information
The single-engine Aeronca 11AC, serial number 11C-277, was manufactured in 1946. It was powered by a 65-horsepower Continental Motors A-65-8F engine, serial number 5767568. The two-seat airplane had a maximum gross weight of 1,250 lbs, an empty weight of 782 lbs, and a useful load of 468 lbs. The combined weight of the pilot and passenger was 462 lbs. The auxiliary fuel tank contained about 2 gallons of fuel, and the main tank was breached. A weight and balance calculation indicated the aircraft was at least 6 lbs over gross weight at the time of the accident.
The FAA Carburetor Icing Probability Chart from Special Airworthiness Information Bulletin CE-09-35 indicated a probability of serious icing at glide power given the reported temperature and dew point.
Meteorological Information
At 1955, the surface observation at Sawyer International Airport (SAW), Marquette, Michigan, 13 miles northeast of the accident site, reported wind from 050 degrees at 8 knots, visibility 10 miles, clear sky, temperature 17°C, dew point 10°C, and altimeter 30.17 inches of mercury.
Wreckage and Impact Information
The accident site was about 1,200 feet from the approach end of the runway, aligned with the extended centerline, on uneven terrain with tall grass, shrubs, and trees. Rescue personnel found the airplane nose-down with the tail nearly vertical. Pieces of the broken wooden propeller were located 21 feet northwest of the main wreckage. The nose and engine compartment exhibited crushing and buckling consistent with about a 45-degree nose-down impact. One propeller blade was broken near the hub, the other splintered along its span, with damage indicating aft crushing and few rotational signatures. The left wing's leading edge was crushed aft along its span; the outboard section was broken outboard of the wing strut, crushed, and buckled aft. The right wing was broken at the front spar attach point, twisted aft. The rear fuselage and empennage were largely intact. Flight control cables had continuity from surfaces to cockpit controls; breaks in cockpit controls were consistent with overload fractures.
The instrument panel and cockpit showed extensive impact damage. The throttle was full forward, carburetor heat full forward, ignition on BOTH, fuel primer closed and locked, mixture control knob broken off. Carburetor fuel was present. The 8-gallon auxiliary fuel tank aft of the cabin contained about 2 gallons. The fuel selector was on the main tank, which was forward of the instrument panel, completely broken open with no fuel; the cork float was moist. The fuel tank interior had a film of dirt contamination. Vegetation between the initial impact point and wreckage showed fuel blight.
Engine examination revealed that cylinder Nos. 1 and 3 upper spark plugs were finger tight. Suction and compression were produced on cylinders 1, 2, and 3; cylinder 4 lacked thumb compression due to impact damage but piston and valve continuity was established. Oil was found in cylinder 4. Drive train continuity was established. Upper spark plugs were in good condition with normal color and round electrodes. Bottom spark plugs: No. 1 normal; No. 2 lead connected but loose; No. 3 spark plug gap measured 0.009 inch (typical 0.018–0.022). The left magneto was attached, impulse coupling operated, and spark on all towers. The right magneto was separated; when rotated, it also produced spark on all towers.
Medical and Pathological Information
An autopsy of the pilot was performed at Duke LifePoint Hospital, Marquette, Michigan, on July 19, 2016. The cause of death was multiple traumatic injuries sustained during the airplane crash. A Forensic Toxicology Fatal Accident Report by the FAA Civil Aerospace Medical Institute was negative for all substances tested.