Undoubtedly ! " We do NOT use Christian names on the flight deck, MR. XXXX " I was once admonished.
You're not wrong there !
A relative of mine worked for BEA in those days as ground staff and said "Good morning" to a Captain as he walked past him in the corridor. Response was "People like you don't talk to people like me."
Unbelievable these days, but 40-50 years ago things were different.