Sergeant Callan is a U.S. Army sergeant who makes a one-time appearance in the Season 4 episode of M*A*S*H titled "Dear Ma". The part of Sergeant Callan was played by Redmond Gleeson.
About Sergeant Callan[]
Callan is a patient of B.J.'s. Just as he is about to leave the 4077th on a bus, he tells B.J. he needs money urgently for an operation for his wife. He offers to sell B.J. a watch which he says he bought for $150 at the Tokyo PX. He tells B.J. he will take any amount for it. B.J. gives him $20. Not surprisingly the watch turns out to be a dud and B.J. realizes that he has been conned. But he gets his own back on Callan when he a patient at the 4077th for a second time. Inside the O.R., Callan asks B.J. if he will be all right. B.J. reassures him that he "running like that watch in no time." B.J. then asks the nurse for a rusty saw!