Originally Posted by
HEATHROW DIRECTOR
I never heard of either operational or "due regard". I guess they are local phraseology. I once worked with the USAF and it was a culture shock to start with but great when I got used to it! Good luck.
"due Regard" refers to a phrase in the original ICAO agreement, whcih is still the basis for international aviation. In Article 3, it (and I'm paraphrasing) notes that State (Military, customs and police) aircraft may operate outside of ATC procedures, as long as they exercise "due regard" for the safety of civil air traffic. As it is based in the ICAO founding documents, it's not exactly "local". However the only places I've heard it used was when flying in places where military operations were taking place. I was aware of "due regard" operations, I just wasn't aware that "operational" referred to the same thing.