On June 18, 1997, at 1355 eastern daylight time, a Roe-Wayne Mustang II, N11WJ, piloted by a commercial pilot, was destroyed during a collision with trees and terrain while on a landing approach at the Austin Lakes Airport, Portage, Michigan. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 test flight was operating without a flight plan. The pilot was seriously injured. The flight departed Portage, Michigan, exact time unknown. According to the pilot's family members, the pilot cannot recall the events surrounding the accident. One witness, a friend of the pilot, said N11WJ was making its first test flight after Federal Aviation Administration certification. This witness said N11WJ's approach path was "...to flat... ." The witness said he saw N11WJ's left wing "...dip..." shortly before the airplane pitched down and collided with the trees. A second witness said N11WJ's initial glide path on final approach looked correct. He said, "All of a sudden, he looked like he was settling faster than he should." He said N11WJ made a gentle turn away from the final approach path toward the trees. He said he did not see the airplane stall. The witness said it appeared to him as though N11WJ flew into the trees. The on-scene investigation was conducted by a Federal Aviation Administration Principal Maintenance Inspector (PMI). According to the PMI, N11WJ's engine had internal mechanical continuity. One propeller blade was bent aft about 30-degrees at its midspan point. The second blade was straight. Both propeller blades had various sized chordwise rub marks that were comprised of a mixture of green and brown colors. Both magnetos sparked when rotated by hand. The on-scene investigation revealed flight control continuity for all 3 axes. The PMI said he observed a trace of fuel in the flow divider. The PMI said the flow divider was installed upside down, underneath its mounting bracket. He said he did not observe fuel in the undamaged electric and engine-driven fuel pumps. The PMI said he observed about a tablespoonful of fuel in the fuel servo. The PMI said he did not observe any fuel in the line between the fuel servo and flow divider. According to the PMI, the fuel he observed was yellow in color and had an odor similar to auto fuel. The PMI said N11WJ's fuel lines were intact. He said he did not observe any fuel in the lines. He said the wingtip auxiliary fuel tanks were empty and that the fuselage fuel tank had at least 5 gallons of fuel in it. The PMI said the fuel tank vent on the bottom of the fuselage and was not plugged. The vent line extended vertically out of the fuselage about 1-inch and had its end cut at an approximate 45-degree angle. The angled-end faced aft, away from the normal inflight airstream. The PMI said N11WJ's engine-driven and electric fuel pump were installed in series (in-line) forward of the fuel strainer. This system design was setup with the fuel supply (fuselage tank) feeding into the fuel strainer that in turn fed into an electric fuel pump. This pump then fed into the engine-driven fuel pump. The fuel servo was bench flow checked and met the manufacturer's specifications. The pilot did not submit an NTSB 6120.1/2. The Federal Aviation Administration Principal Operations Inspector gave a family member a copy of this form, requesting they help the pilot in filling it out when he recovered from his injuries. A copy of this form was also mailed to the pilot on June 25, 1997, by the NTSB investigator-in-charge. The pilot did not return either form.