Bill
Why is this on Military Aviation?
Sometimes military aircraft land at civil airfields, including LHR.
I had an ex-Herc mate who, when he was on BA 757s, kept going on at me over a beer - "Why do you LHR controllers give us 2 minutes behind a Heavy when we rotate way before the place that they had?".
My reply was that the rules don't allow me to shorten the time behind a Heavy, but if you or anyone else ask me for clearance for take off stating that you don't need the 2 minutes then my reply will be " Cleared for take off at your discretion ", strictly speaking I should also have reminded him he needed 2 minutes behind a Heavy, but as they had already told me that didn't want 2 minutes I omitted that!
Thankfully I reached retirement without an incident that would have caused a " No coffee " interview!