Engine oil sprayed over the windshield of a Piper single-engine aircraft April 28, blocking the view of the three men onboard who attempted to land the plane, according to a National Transportation Safety Board preliminary report released May 7.Ernesto Antonio Arteaga-Membreno, 28, of Grayson was the flight instructor aboard the plane that went down on Browns Bridge Road at Waldrip Circle just after 5 p.m. April 28, according to Forsyth County authorities. He was found dead at the scene.Litsu Chen, 30, of Lawrenceville and Shen Yang Wu, 25, of Duluth were both injured and transported to Northeast Georgia Medical Center.