Accident Overview
On October 5, 2013, at approximately 1600 eastern daylight time, a Cessna 172F (registration N8715U) sustained substantial damage during a forced landing following a total loss of engine power near Gainesville, Florida. The commercial pilot and a pilot-rated passenger received minor injuries. The local banner tow flight had departed Gainesville Regional Airport (GNV) about 1540. Visual meteorological conditions prevailed, and no flight plan was filed for the Part 91 flight.
Pilot's Account
The pilot reported that a preflight inspection revealed no anomalies. After departure, he performed the banner pick-up and proceeded toward the stadium where the banner was to be towed. He leveled the aircraft at 1,200 feet above ground level (AGL), reduced engine power to 2,250 rpm, and leaned the mixture. He then extended wing flaps to 10 degrees and slowed to 50 mph. About 20 minutes into the flight, he noticed a descent of approximately 100 feet. He increased engine power and enriched the mixture, observing that the oil temperature gauge indicated "hotter than normal." The aircraft continued to descend and oil temperature rose into the red arc, followed by a total loss of engine power. The pilot released the banner, attempted unsuccessfully to restart the engine, and conducted a forced landing to a nearby field. He stated that due to "excessive airspeed" upon touchdown, the aircraft bounced and struck a parked truck, causing substantial damage to the fuselage and both wings.
Pilot Qualifications
The pilot held a commercial pilot certificate with ratings for airplane single- and multi-engine land, an instrument rating, and a flight instructor certificate with single- and multi-engine and instrument airplane ratings. His most recent first-class FAA medical certificate was issued in September 2013. He reported 2,513 total flight hours, with 1,402 hours in the accident aircraft make and model.
Aircraft Information
The 1965-manufactured Cessna 172F was equipped with a Lycoming O-360-A1A, 200 hp reciprocating engine. Its most recent annual inspection was completed July 24, 2013. At the time of the accident, total aircraft hours were 4,989. According to the operator, the aircraft was operated on automotive fuel. Review of airworthiness records revealed no supplemental type certificate authorizing automotive fuel use.
Post-Accident Examination
Following the accident, the aircraft was removed and examined by an FAA inspector. The engine exhibited little impact damage. The carburetor remained attached, but the carburetor heat cable was disconnected and hanging free. Magnetos were attached and undamaged. The engine contained 7 quarts of oil; the oil filter showed no anomalies. Spark plugs appeared "blackish." The electric fuel pump and starter were replaced, and the engine was secured for a test run. Using the onboard fuel, the engine started and ran for several minutes without issues.
A fuel sample taken from the carburetor before the test run was sent for analysis. A Karl Fisher water test revealed "high" water content, and a microbial test was negative for bacteria and fungus. The sample quantity was insufficient for distillation and flash point tests, so ethanol presence could not be determined.
Weather Conditions
The 1553 recorded weather at GNV (5 miles southwest of the accident site) included wind from 090 degrees at 6 knots, 10 miles visibility, clear skies, temperature 31°C, dew point 19°C, and barometric altimeter setting 30.00 inches of mercury. An FAA carburetor icing probability chart indicated potential for serious icing at glide power under the prevailing atmospheric conditions.