When I left an A320 today, the fuel truck was already there and refueling the aircraft. (At least, the hose was connected.) Also, a FA said they will fly back within 40 minutes.

This isn't much time, and I wonder if they start to refuel the aircraft before actually calculating the required amount. (Since it's a 4h flight, they'll need quite some fuel.)

So I'd like to know how much time is needed for flight planning of an airliner. Maybe some planning for the next flight can already be done in advance during the current flight? Maybe some part can already be done by others? Or does the entire process take just a few minutes today?

It's also not clear to me what is done during flight planning. Of course planning the route, including possible ways to divert the aircraft, and amount of fuel. What else?

EDIT: To make it more clear: I'm asking about the work the pilots have to do to prepare for the next flight

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    $\begingroup$ Timelapse of turnaround operations --- Repetitive flight plans (RPL) are usual and there is a team in the airline for flight planning and dispatch. $\endgroup$
    – mins
    Jun 3, 2016 at 8:19
  • $\begingroup$ This question is rather broad, however, I think Mike has probably nailed the gist of what the OP is after. Maybe some rewording along the lines of "how is flight planning handled to allow for an individual plane to have a 40-minute turnaround between gate arrival and push back", would help? $\endgroup$
    – FreeMan
    Jun 3, 2016 at 12:09
  • $\begingroup$ @mins - if only that time lapse indicated how much real time had passed... $\endgroup$
    – FreeMan
    Jun 3, 2016 at 12:12

3 Answers 3


The pilots don't do the flight planning. It is done 1-2 hours before the flight by dispatchers using computer software.

On a quick turnaround, one pilot goes to a printer to retrieve the flight plan. The other stays with the aircraft and prepares for the next flight.

Sometimes someone will bring the flight plan directly to the aircraft. Some airlines have stopped using paper flight plans and instead download to an iPad.

The pilots review the flight plan to ensure it meets all requirements, and can request a reroute, or additional fuel it they feel it is needed.


When is flight planning done?

Anytime convenient! Honestly. You can plan for a trip 3 hours later, tomorrow, next week, or even next month. There're already pre-defined airways on most areas you'll fly above; you just need to lookup the charts and select yourself a route.

Now, unlike a family road trip, commercial flights are flown everyday. Every pilot assigned to the flight will make that trip. So, no, pilots do not arrive at the gate, being told "Your next hop is going to Hawaii", then grab the charts, lay them out on a nice big table, and figure out which waypoints to go. Somebody at the company has already done that for them. That somebody is called a dispatcher.

And remember, it's the same route flown over and over again, day by day. You only have to plan once.

When do I know how much fuel to take?

To figure that out, you need to know how much cargo and how many passengers are going on this flight. When will you know that? A few hours before departure, you already have a good estimate (given that usually x% of passengers will turn up). By the time check-in for this flight is closed, you have the exact number. Just plug in that number into a calculator and you'll get your fuel requirement. Even without computers, this calculation takes only a minute.

Pilots' responsibility

The pilots (in particular the captain) has the final and unquestionable authority over any matter of the flight, including its flight plan. That said, pilots are not the ones who come up with the initial plan. In airline operations, the pilots' responsibility is to adjust the plan as necessary. For example, if bad weather is expected at the destination, the captain might request extra contingency fuel.

So in short, the pilots' responsibility include:

  • Familiar themselves with the planned route
  • Review the weather forecast and NOTAMs, and adjust the flight plan if necessary
  • Verify the weight and balance is appropriate (taking into consideration cargo, fuel and passengers. Again, somebody has already done the calculation for them.)

That's not much, indeed.

  • $\begingroup$ winds and other weather conditions affect fuel load significantly, so it's not true that you only have to plan once. $\endgroup$ Jun 4, 2016 at 3:21
  • $\begingroup$ @pericynthion Yes and No. Jet streams are present all year along; its strength and location does vary, but within limits. Furthermore the software used by dispatchers can take winds aloft into account. So you only plot the route once. You figure out cruise speeds, cruise altitudes etc. a few hours before takeoff. Sometimes you have to re-route around volcano eruptions and hurricanes, but that's not often. $\endgroup$
    – kevin
    Jun 4, 2016 at 5:55
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    $\begingroup$ The first paragraph makes it sound like you can plan a flight a month after it happened... $\endgroup$
    – Ben
    Jun 4, 2016 at 7:30
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    $\begingroup$ @kevin, depending on where you are flying, you might also need to reroute around congestion, strikes and other disruptions. I don't know how often they happen, but I would think more often than volcanoes. $\endgroup$
    – Jan Hudec
    Jun 6, 2016 at 18:47

Well, a 40 minute turnaround time can be quite short to leave time for planning.

Mind you it's not just about choosing an appropriate flight route, but weather considerations, reading Notams, winds, choosing an appropriate flight level, deciding on extra fuel, choosing takeoff alternates, en-route alts, destinations alts, then the w/x and Notams for those alternates, etc. It can probably be done in 30 minutes , but it will be hairy.

Normally all my sectors (legs?) are pre-planned/read/briefed at the beginning of a work day. Deciding on most important factors before we even go to the plane. Then, when we have to do a 40' (30'?) turnaround it makes it all much easier. Most times we can call ground handling companies via VHF before we even land, informing them in advance of the services we need (including the amount of refuelling).

How long does flight planning take

Computers print an OFP in probably under 1 minute. Then maybe 5-10 minutes for the pilots to read/change/understand/brief.

when is it done

At the beginning of the work day

how is it done?

uhm.. see above

I'm asking about the work the pilots have to do to prepare for the next flight

Ok, different question as it is not so much planning related:

  • Refuel
  • walk-around check
  • prepare the FMC (in one way or another)
  • review the mass&balance loadsheet
  • compute takeoff speeds
  • review and brief the departure

and you are good to do. Did I forget anything?


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