CHI97LA267

Following an agricultural flight, the pilot noticed that the right fuel tank was reading under 1/8 full and the left fuel tank was 1/4 full. The pilot opened the overflow valve and slipped the airplane to balance the fuel levels. The pilot did this maneuver twice and the fuel gauge indicated 1/8 full in both tanks. The pilot said that the fuel pressure was then lost and a total power loss occurred. He tried the regain fuel pressure by using the wobble pump but could not restart the engine. The airplane was moved and disassembled by the owner before the fuel tanks could be inspected. The owner said that the airplane manufacturer said fuel feed problems are caused by an air leak in the cover plates on the fuel tanks. The pilot did not dump his chemical load following the loss of engine power.

On August 23, 1997, at 1045 eastern daylight time (edt), a Wsk Pzl Mielec M-18A, N178RA, registered to Hatfield Spraying Services, Inc., of Nunica, Michigan, was substantially damaged following a total loss of engine power and subsequent forced landing in a farmer's field. The commercial pilot reported no injuries. The 14 CFR Part 137 aerial application flight was not operating on a flight plan. Visual meteorological conditions prevailed at the time of the accident. The flight departed Nunica, Michigan, at 0945 edt.

According to the pilot's written statement, he was returning from spraying a field when he noticed a lower fuel level in the right tank than in the left tank. He decided to open the overflow valve and slip the airplane to allow the fuel in the left tank to flow into the right tank. The fuel level in the left tank was 1/4 full with the right tank indicting under 1/8 full. After 30 seconds of slipping the airplane, he leveled out and notice that both tanks indicated 1/8 full. The pilot did this procedure again after several minutes passed. The pilot said that the engine lost fuel pressure and had a total power loss. Restart attempts by re-establishing fuel pressure with the wobble pump failed to restart the engine. The pilot had 200 pounds of chemicals on board but chose not to dump his load, because he was concerned about creating a spill. While selecting a field to land in, the pilot said, "...to make my approach to it (field). While extending or continuing the left turn, I lost more altitude than anticipated and clipped the top of one tree with the left wing." The airplane came to rest in a soft cornfield.

According to the Federal Aviation Administration (FAA) Inspector, the wreckage had already been moved from the site and disassembled upon his arrival. The owner of the company said that there was a problem with the fuel system on the M-18A. The owner reported that the factory believes that fuel problems are caused by the cover plates on the fuel tanks having leaks in low pressure area of the wing, causing fuel not to flow uniformly from the tanks. This could not be verified by the FAA Inspector.