Doohan died at 5:30 a.m. (1330 GMT) at his Redmond, Washington, home with his wife of 28 years, Wende, at his side, Los Angeles agent and longtime friend Steve Stevens said. The cause of death was pneumonia and Alzheimer’s disease, he said.
The Canadian-born Doohan fought in World War II and was wounded during the D-Day invasion, according to the StarTrek.com Web site. He was enjoying a busy career as a character actor when he auditioned for a role as an engineer in a new space adventure on NBC in 1966. A master of dialects from his early years in radio, he tried seven different accents.
When the series ended in 1969, Doohan found himself typecast as Montgomery Scott, the canny engineer with a burr in his voice. In 1973, he complained to his dentist, who advised him: “Jimmy, you’re going to be Scotty long after you’re dead. If I were you, I’d go with the flow.”
“I took his advice,” said Doohan, “and since then everything’s been just lovely.”
Rest in peace, James Doohan. I never knew you faked that accent.
Aaron Fulkerson 
RIP Scotty. You’ll forever be remembered for your “she’s giving us all she’s got cap’n!” I wonder how many decades that will last? My pledge to you Doohan: No one will forget that quote as long as I live! 🙂