Bob Mason wrote a sequel to "Chickenhawk" entitled "Chickenhawk - Back in the world - life after Vietnam". ISBN:0140158766
There isn't any flying in it, but Bob's description of his life after experiencing the horrors of Vietnam is a very moving, open, honest confession of what he became. If the last page of "Chickenhawk" shocked you, then get hold of this book (and a box of tissues if you cry easily).
Very highly recommended.