LAX98LA027

While executing an instrument landing system approach to Sonoma County Airport, the airplane experienced a loss of engine power. The airplane was substantially damaged during a forced landing in a vineyard about 1/2 mile short of runway 32. The on-site FAA investigator stated that there was no smell of fuel when he arrived on scene, but the fire department personnel had reported smelling fuel when they arrived at the scene. Both the left and right fuel gauges read zero when the aircraft master switch was on. There was no indication that the propeller was turning when the airplane struck the ground.

On October 31, 1997, at 0925 hours Pacific standard time, a Piper PA-32R-300, N1655H, was substantially damaged during a forced landing following a sudden engine stoppage 1/2 mile short of runway 32 at Sonoma County Airport, Santa Rosa, California. The solo commercial pilot was not injured. The flight departed Oakland, California, en route to Santa Rosa on a visual flight plan. The flight was being operated by Ameriflight, Inc., of Burbank, California, as an on-demand charter and cargo service. Visual meteorological conditions prevailed at the time and an instrument flight plan had been filed.

The Federal Aviation Administration inspector stated in his report that, although the fire department personnel had smelled fuel when they arrived at the scene, both the left and right fuel tanks were empty. When the master switch was turned on and the fuel selector placed in the left and right tank positions, both fuel gages read zero.

The aircraft engine was subsequently inspected at an aircraft salvage yard and no incorrect assembly, internal failure, or excessively worn parts were found. The magnetos had proper internal and external timing and the ignition harness was intact and functional. Following the inspection, the engine was hooked up to an auxiliary fuel supply, a dummy prop installed, and then started. The engine ran normally up to 20 inches of manifold pressure and 2,200 rpm, the highest that could be safely evaluated on the test stand, with no observed malfunctions.

Following the engine run, the fuel supply can was tipped to uncover the suction tube and interrupt the fuel supply simulating running a tank dry. As soon as the engine started to sputter, the can was righted and the electric boost pump turned on. Although indicated fuel pressure returned to normal, the engine continued to run rough for about 2 minutes and there was no response to throttle or mixture control movements. After approximately 3 minutes, the engine resumed normal operation. This whole process was then repeated with identical results. (The results of this experiment roughly approximated the symptoms described by the pilot that occurred just prior to the forced landing.)