I read that the scene when Colonel Blake's chopper went down , that only a few people on set knew what was going to happen .
The writers and directors kept it a secret because they wanted a honest reaction from the cast ........Radar ( who told everyone ) was told between scenes what to say .
It went on to say that even though everyone knew it did not happen, some of the cast cried .
McClean Stevenson (Blake) was envious of taking a back seat to Alda (Hawkeye)
Stevenson wanted equal billing as Alda, and Alan Alda money, which CBS wouldn't give, so he left in what could be called a hissy fit.
Wayne Rogers story was basicly the same as Stevenson, was jealous of Alda.
What those two did not realize that Jamie Farr and Loretta Swit did was Alda was so much more than Hawkeye to that show, he directed behind the scenes and consulted on writing also.
Stevenson and Rogers career went into the toilet after they left.
(Would not be surprised if the two were blackballed -CBS had major clout back then)