Current ACAS is an engineer - Richard Knighton.
He has had a number of high profile non-engineer posts - see
here, which would fit him well for the "heights"
But ACAS is only (sic!) a 2-star post, so there's a long way to go yet - but he certainly has the time - born in '69. That's after I joined ......
And he's about 4 years younger than Jock Stirrup was when
he was ACAS ........