Here's a fairly basic way of doing fuel planning -
You have two figures that you work with. First hour, and Continuing Hours. Your first hour figure will be pretty high because you figure in taxi, takeoff, and climb. Every hour afterwards, you figure for cruise power fuel consumption. Descent and landing don't change the total enough to make that much of a difference to calculate it separately.
For the Convair 580, we used 1400 pounds for the first hour and then 700 pounds for each hour after that.
For the HS.748, I'm using 1000KG for the first hour and 500KG for each hour after that. Being that most flights so far have been at an hour, 800KG is more than enough.
So, if you know what your cruise fuel flow is in LBS or KG, take that round it to the nearest hundred, double it, and that'll give you your first hour consumption. For every hour afterwards, figure at your cruise fuel flow. Then, for your alternate, again, take the first hour fuel flow (because you're going from a missed approach, climbing to a low cruise and then proceeding to the alternate) for the first hour and then if the flight takes more than an hour to get to the alternate (happens occasionally) add your cruise flow again for any further time. Basically, you plan fuel for your alternate as if it's a second flight.
Finally, you take your cruise fuel flow and multiply it by 75% to get how much fuel you need for your required 45 minute reserve. In the HS.748's case, it would be 375KG. So that means (in a perfect world) I should never land with less than 375KG of fuel in the tanks if I did not have an alternate and did not have to hold.
Always be sure to add additional fuel for especially high headwinds, weather along the route, or known delays (like if you know you'll probably be holding for an hour on the approach because you're going into Gatwick and it's during a major fly-in on your chosen online network).
Anyways, I stand to be corrected on the planning numbers for the HS.748, but that's what I've observed so far in the sim and it's working out okay. I'll try to fly some of the other aircraft and put up figures for them.
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