A Montauk man was flown to Stony Brook University Hospital after he was hit by a car while riding his bicycle in Montauk Friday. East Hampton Town police are still investigating the accident, which occurred on Flamingo Avenue just south of Falcon Place at 4:04 a.m. Raymond Eng, 80, of Briarwood, Queens, was driving a 1995 Volvo north on Flamingo Avenue when he struck Raymond W. Bimson, 32. Police did not indicate which direction Mr. Bimson was traveling on his bicycle. The Montauk Fire Department's ambulance company treated Mr. Bimson, and a Suffolk County police helicopter airlifted him to Stony Brook. As of Friday afternoon, he was listed in stable but serious condition. Mr. Eng was not injured. His Volvo was impounded for a safety inspection. Police have not yet determined what caused the accident. Anyone who may have witnessed the accident has been asked to call East Hampton Town police at 537-7575.