N830JT

On February 1, 1998, at 1515 central standard time (cst), a Chinese A/F Aero Industries Development PL-1B, N830JT, piloted by a commercial pilot, was substantially damaged during a collision with the ground while maneuvering for a forced landing. The pilot reported a total loss of engine power during the airplane's departure climb following takeoff from runway 18 at the Aurora Municipal Airport, Sugar Grove, Illinois. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 flight was not operating on a flight plan. The pilot and passenger reported no injuries. The flight departed Sugar Grove, Illinois, at 1512 cst.

The pilot said that he was doing touch and go landings with the accident occurring on his third or fourth time around. He said that he took off on runway 18 and started to climb. The pilot said that he was climbing out at 100-feet above the ground when the "... engine stopped... ." He said the boost pump was "ON" and that he checked the throttle, mixture, and boost pump selectors after the engine stopped running. The pilot said he "... turned west to avoid [a] road and wires." According to the pilot, the engine started and ran for about 3-seconds when the airplane was about 25-feet above the ground. The pilot said he "...thought [he] could make runway 9...," and banked the plane toward the runway. During this maneuvering the engine stopped running a second time. The pilot said he "...leveled the wings and let [the] plane settle in." The airplane collidied with the ground and came to rest facing south.

The right main gear was folded under the airplane and the nose wheel was sheared off. The fuselage had wrinkling at the firewall and behind the cockpit. The outboard half of the left wing was bent upward about 45-degrees. The right wing was bent upward about 15-degrees at the wing root. It leading edge was crushed upward and aft.

The on-scene investigation revealed no pre-accident mechanical anomalies with the airframe, engine, magnetos or fuel system that would prevent flight. The spark plug electrodes were black and sooty in appearance. The propeller had one blade bent aft approximately 5-degrees at the midpoint. The fuel smelled similar to autogas. There was a tablespoon of fuel obtained from the carburetor float bowl. The fuel line between the carburetor and fuel pump was cracked.

The PL-1B's design for the carburetor heat system is to use radiant heat from the oil cooler. There is an air scoop for the carburetor at the front of the airplane's cowl that extends aft and is attached to the carburetor throat opening. The oil cooler is located aft and above the air scoop inlet. Air enters through the oil cooler's opening and passes over the oil cooler. The warmed air from the radiant heat of the oil cooler then travels about 14-inches to the carburetor body. This is the only means available to the pilot for prevention or elimination of carburetor ice.

On the day of the accident the temperature and dew point was 36 and 34-degrees Fahrenheit respectively. There was also moderate rain at the time of the accident. According to the FAA's carburetor icing probability chart, the airplane was operating in conditions conducive to serious icing at cruise power settings.