A head on collision near Sisters this sent several people to the hospital; one went by air ambulance.  Deschutes County Sheriff Lt. Deron McMaster says the head-on collision happened about one mile east of Sisters on Highway 126.  The crash involved a motor home and a passenger car.  The driver in the passenger car is the one who was taken to the hospital by air. Lt. McMaster says the early investigation shows that speed was probably a big factor:  “The time between Memorial Day and Labor Day, obviously its summertime, a lot of people out recreating.  Road conditions are generally pretty good, dry pavement, there’s no snow or ice or anything, so people have a habit of increasing their speed.  But speed is the number one cause of accidents nationally even above that of drugs and alcohol."  Hhe says at this point they don't know if drugs or alcohol played a role in the head-on crash.