The pilot, who was the builder of the experimental single engine airplane, was making the first flight after having completed several high-speed taxi tests and ground runs of the engine. The pilot stated that shortly after becoming airborne and during the initial climb, he began to notice oil on the windshield. When he returned to the airport for landing the oil was significantly reducing his forward visibility and he had difficulty judging his height above the ground. During the landing the airplane “touched down hard and bounced”. On the second touchdown both main landing gear legs collapsed and penetrated through the top surfaces of the wings. The solo pilot was not injured. Two weeks after the accident the pilot said he still had not been able to determine the source of the engine oil leak.