History of Flight
On September 1, 2012, at approximately 0830 eastern daylight time, an Aeronca 7AC, registration N82383, sustained substantial damage when it impacted terrain following a loss of control during initial climb from Brighton Airport (45G) in Brighton, Michigan. The private pilot sustained serious injuries, and the passenger sustained fatal injuries. The flight was conducted under 14 CFR Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed.
According to local authorities who spoke with witnesses, the pilot was taking the passenger for a local flight. Witnesses observed a normal engine run-up and takeoff from runway 22. Shortly after takeoff, the engine did not sound like it was developing full power, and the airplane struggled to climb. Subsequently, witnesses observed the airplane make a 180-degree turn and then descend toward the terrain in a nose-down attitude.
Personnel Information
The pilot, age 79, held a private pilot certificate with ratings for airplane single-engine land, airplane multi-engine land, and instrument airplanes. The pilot held a valid driver's license for operation of light-sport aircraft. His most recent third-class medical certificate was issued on August 10, 2005. The Aeronca 7AC is defined by the FAA as a light sport aircraft (LSA). Pilots flying LSAs are required to possess a valid driver's license and comply with 14 CFR 61.53(b), which prohibits acting as pilot in command while aware of any medical condition that would make them unable to operate the aircraft safely. A review of the pilot's logbook showed that he had accumulated 2,686.5 total flight hours, with 7.8 hours in the last 60 days. His most recent flight review was completed on August 4, 2012.
Aircraft Information
The Aeronca 7AC, serial number 7AC-1016, was manufactured in 1946 and registered to the owner on June 10, 2008. It is a two-place, tandem, high-wing monoplane with welded tube and fabric construction, powered by a Continental A-65-8, 65-horsepower reciprocating engine and a fixed-pitch wood propeller. The pilot's operating handbook listed a clean stall speed of 38 mph. The most recent annual inspection was completed on November 22, 2011, at a total time of 2,391.5 hours. At the time of the accident, the airplane had accumulated 27.2 hours since that inspection. Although the airplane held a standard airworthiness certificate, it met the definition of a light sport aircraft per 14 CFR 1.1.
According to the pilot's friends, the pilot routinely fueled the airplane with automotive gasoline. The airplane's records did not show a supplemental type certificate (STC) for automotive gasoline use. An Experimental Aircraft Association flight manual supplement states, "When using unleaded automotive gasoline, the onset of carburetor ice may occur earlier under the same atmospheric conditions than when using 80/87 minimum grade aviation gasoline."
Weight and balance information showed an empty weight of 765.5 lbs and a maximum gross weight of 1,220 lbs. Medical records indicated the pilot weighed 176 lbs, and the autopsy report listed the passenger's weight as 127 lbs. The total fuel on board at the time of the accident was unknown. Based on occupant weights, the remaining useful load without fuel was 151 lbs. The total fuel capacity was 13 gallons (78 lbs). Aero Fabricators shoulder harness and seat belt assemblies were installed in the front and rear seats on November 10, 2010, per STC SA1768GL.
According to an individual who owned a hangar near the pilot's hangar, during the most recent annual inspection, the pilot prepped the airplane, including removal of the seats and lap restraints. Upon completion, the pilot reinstalled them.
Meteorological Information
At 0815, the automated weather observing system at Livingston County Airport (OZW) in Howell, Michigan, 9 miles west of the accident site, reported calm wind, visibility 10 miles, clear sky, temperature 19°C, dew point 13°C, and an altimeter setting of 30.15 inHg. The FAA icing probability chart indicated potential for serious carburetor icing at glide power at the time of the accident.
Wreckage and Impact Information
The airplane came to rest upright in swampy terrain approximately 1,000 feet from the departure end of runway 22. The engine was buried within the terrain and displaced aft into the firewall. The fuselage was crushed upward and aft. The empennage was partially separated and displaced to the right. Flight control continuity was established from all surfaces to the cockpit. The wooden propeller remained attached with leading edge gouges and splintering. The crankshaft rotated by hand, and continuity was confirmed from propeller to rear accessory gears and valve train. The carburetor remained partially attached but impact-damaged; the float bowl contained fuel and water. The float was undamaged, and the fuel intake screen was clear. The carburetor heat control at the engine was found in the OFF position.
Additional Information
According to the pilot's operating handbook, the emergency procedure for engine roughness includes pulling carburetor heat full on. If roughness is caused by carburetor ice, roughness will probably increase momentarily then smooth out. If not, check magnetos; land as soon as practical.
Another accident involving a failed Aero Fabricators shoulder harness occurred on March 3, 2013, in a Cessna 172M; the pilot was fatally injured. During that investigation, the NTSB observed a similar shoulder harness failure with separation of the threading at the "Y" junction.
Medical and Pathological Information
The pilot's injuries included posterior dislocation of a left hip prosthesis with acetabular fracture, left elbow fracture, periorbital bruising with orbital floor fracture, compartment syndrome in the right forearm, and bruising across the shoulders and right side ("seatbelt sign"). A CT scan showed intracranial bleeding and swelling. The passenger's cause of death was determined to be multiple injuries.
Survival Aspects
The pilot's seat had its four posts attached to the floor, with the frame bent down, forward, and to the right. The pilot's restraint (Aero Fabricators model H-702-300, installed November 11, 2010) had a shoulder harness separated at the stitched "Y" junction. The lap belt was pinned between the installation bolt and seat frame, preventing adjustment. The passenger seat had its posts attached, with the front frame tube creased. The passenger's shoulder harness was intact. The lap belt was similarly pinned.
During examination, bushings that would allow proper lap belt adjustment were not found in the attachment fittings. The mechanic who installed the restraints stated he had installed bushings, but they were missing.
Shoulder Harness Testing
Breaking strength tests on exemplar webbing showed it met the SAE AS 8043B requirement for upper torso (17.8 kN) but not for pelvic (22.2 kN). However, the webbing met the TSO C22f standards in effect at the time of STC approval. Static tests on exemplar and accident harnesses all failed at the "Y" junction stitching at loads between 1,202 and 1,281 lbs, below the rated strength of 1,500 lbs. Additional testing in August 2013 using a mock-up seat showed failure at approximately 1,105 lbs (torso) and 1,645 lbs (lap). The FAA reviewed STC SA1768GL and determined it complied with applicable regulations at the time.
Engine Examination
On January 10, 2013, the engine was examined and functionally tested by FAA inspectors. Damaged components (propeller, ignition harness, intake tube, oil, fuel) were replaced. The engine was started, both magnetos operated, throttle was cycled, and power was confirmed. Oil pressure maintained a minimum of 30 psi.