Originally Posted by
The Many Tentacles
It can easily be that long. We have to get approval from the airport before we can send you there and that's what takes the time.
For the actual ATC side of it, it's pretty easy. It involves us putting a new route into the computer to make sure the right sectors get your details, coordinating with the next sector if required and then telling you the route, except you probably already know that, but we have to tell you anyway
and what happens as soon as we say the magic word? Permish goes out of the window. I guess this is where these guys got to. As soon as one called it, I bet the other two piped up pretty quickly.
The reality is not everyone is operating to this level of fuel, due to the range of flight durations and conditions encountered enroute. there is therefore a distribution of endurance as people hit the stack.
Problem is, there are the unknown unknowns (not talking about your prob 30 tempos that turn out far worse) like drones or security events in the terminal. Statistical contingency can’t account for this, neither can 5%/5 mins holding on a short sector.
Airlines have an overriding responsibility for safety, but also consider operational efficiency.sometimes benign conditions together with modern commercial, very accurate planning systems, when a “black swan” event occurs can really screw things up. We don’t use string on a map, fold lines or rules of thumb.
anyhow, something must be working. When was the last time aircraft were falling from the skies with dry tanks? What helps is London Air Traffic being literally awesome and by far the best controllers we work with. East coast USA? Bad weather at destination? Give me another two tonnes minimum.
Military flying generally involved filling the tanks or going up to MTOW as you need the operational flexibility it gives in theatre with turd atc and no proper support on the ground, not to mention “the fog”, plus operating with a vastly inexperienced (but well meaning) operational control structure. The commercial world has comparatively a far more benign operational environment, with far greater comms capability and very experienced people on the ground (multi decade experience) with data from acars and lacking a lot of the fog of war. This means you can SAFELY plan to lower margins of fuel.