The studio actually thought it was inviting *William* Conrad - who looked like balding, paunchy Pappy Boyington - for the audition, and Robert Conrad was summoned by mistake ... but so impressed the studio with his cocky pugnacious - ergo very Boyington - manner and delivery that they wisely hired him.
Conrad took up flying thanks to the series.
He had 2 wives - the second was Miss Teenage America for her year and very young when they got married - and remained on very good terms with both after the divorces. He sired 8 children and had *18* grandchildren. He was a German-American by the name of Falkowski from Chicago.
I remember reading that the stunningly beautiful Janet Leigh - Psycho shower scene - Welsh Princess Morgana in The Vikings - disproportionately well endowed for her otherwise slim blonde North European American figure - daughter Jamie Curtis inherited that - and Conrad had an ongoing relationship at Janet's ski resort. Some strapping Swede lipped off there and not-tall Conrad punched him out.
Boyington would have approved.
He said that later assassinated young Chicago mobster and briefly B movie actor Michael Spilotro was his best friend.