Tuesday, October 25, 2016
When I look out the window, I see nothing but water.
I will often hear someone say that there is no way they would fly to
Hong Kong or Australia.
Maybe even Europe, because it is too much of a
challenge. Why? Because 14 hours in the air over nothing but ocean sounds
Flying over long expanses of water is planned out with many turnaround points built in called go/nogo waypoints. When each point is reached, a planned track to any airport with a long enough runway and fueling facilities is an option; but rejected if there is no reason to do so.
Remember that pilots file flight plans. That flight plan includes many useful details, both for the pilot, and to inform the Air Traffic Control system every step of the way. The part that the pilot must calculate is what we call waypoints. Sometimes these waypoints are named points with a specific distance from a shore based radio navaid. For simplicity we will equate a navaid with a ground based direction finder; distance and direction; which is actually given a name on a chart. If you are a pilot, do not write me! You may also make up a waypoint by drawing on a map, every 200 miles a point where you will make a very firm decision. Will I continue to my destination? Will I return to my departure airport? Will I turn now to the closest airport with a runway long enough for my size airplane? These other airports, not visible from the airplane could be hours away, but are all circled and referenced on a chart.
There are other details that we look into, and the options are plentiful. Each time we reach a named fix, or a 200 mile mark, we call the closest Air Traffic Control facility. And this is what we tell them. “This is our location, in miles and altitude. This was the moment in time we arrived there. This is how many hours of fuel we are carrying. Everything is great (we don’t really say that) so we will continue on to our next waypoint. We will get to that waypoint at a specific time and if we descend, we plan to be at this specific altitude.”
Now let’s say, somewhere between this waypoint, and the next waypoint, we have a problem. Based on the headwinds or tailwinds, the facility we have already picked out, direction of turn, is it faster to 1) continue to destination, 2) return to departure airport, 3) fly to the pre determined alternate. We happen to know that the winds are stronger when we head west bound then when we head eastbound. So as we travel west, we know that it will take a shorter amount of time to turn around and go east then to continue a short distance west.
There is also a go/no go point. If we are traveling east/west, then the mid point of our distance to our destination is NOT the midpoint of our flight. We decide, before we ever leave the flight planning room, where the go/no go point of our flight. Once we pass that point, then we know, we are continuing to our destination or next waypoint, but returning to departure is not an option.
Also you should know that flights over a certain number of hours say 8 hours, requires extra crew members. That way, we share flight time and rest time. A 9 hour trip will carry one Captain and two First Officers. Each pilot will fly at least 2/3 of the trip. A 14 hour Asian flight will have two full crews, or two Captains and two First Officers. Each pilot will fly at least half of the trip.
During flights over long expanses of water, when reaching each waypoint and contacting the nearest facility to make our report, we are legally bound to notate our every word, time, altitude, expected next waypoint, and fuel remaining, right on our flight plan. At the end of our flight, this flight plan is turned in as a document and filed as the log that accounts for the whole flight and is considered an official document. Years later, someone can go back and track the entire flight just by referencing the statistics, documented by the flight crew.
See you in