American character actor Jeff MacKay, the voice of Fireflight in the 1984-87 Marvel Productions series Transformers, died early Friday after a brief illness in the hospital due to liver complications. He was 59.

Familiar to television viewers since the mid-1970s, he had recurring roles in several adventure series, especially as a sidekick.

MacKay portrayed mechanic/co-pilot Corky, pilot-soldier of fortune Jake Cutter's alcoholic best buddy, in the 1982-83 series Tales of the Gold Monkey. He played Lieutenant "Mac" MacReynolds, USN in 24 episodes of Magnum, P.I.

He was Gordon "Gordie" Masterson in the "Dr. Shrinker" segment of The Krofft Supershow from 1976 to 1977.

Other roles included Big Bud Roberts in 10 episodes of JAG, Lt. Donald "Don" French in Baa Baa Black Sheep (later titled Black Sheep Squadron), the Second Crewman in Battlestar Galactica, Buddy in Airwolf, The Greatest American Hero, and Doctor Weinstein in The Greatest American Hero.

Born Jeffery Neill MacKay in Dallas on October 20, 1948, he attended Van Buren Jr. High School, just off Sandia Base in Albuquerque, New Mexico.

He also guested on the TV shows The Duke, The Rousters, Hardcastle and McCormick, Outlaws, Oklahoma Passage, Berlin Break, Kung Fu: The Legend Continues and Diagnosis Murder.