Q330007

[Transalp787]

Hello, this is probably a simple algebra question but I am not getting the reasoning behind it in the explanation. Could someone elaborate on the formula used?

For a planned flight the calculated fuel is as follows:
Trip length is 3:36.
Reserve fuel is 30% of trip fuel.
Taxi fuel is 20 kg
Block fuel is 250 kg
What fuel remains after 2 h 24 min?

Take-off fuel = TRIP(100% TRIP) + RESERVE (30% TRIP) = 130% x TRIP

Take-off fuel = 1.3 x TRIP

Take-off fuel = (250

[Mac]

Block fuel is fuel on Blocks (at the ramp) and so you must subtract taxi fuel to find Take off fuel. 250 -20 = 230 kg

230 kg = 130 % of trip

230 kg

[Mac]

System problem; to continue:

Block fuel is fuel on Blocks (at the ramp) and so you must subtract taxi fuel to find Take off fuel (250 kg - 20 = 230 kg)

230 Kg is 130 % of trip

230 / 1.3 = Trip 177 kg 230 - 177 = Reserves 53 Kg

Trip time 3.36 = 3.6 hours

After 2.24 = 2.4 hours. Then 1.2 hours remain.

Fuel flow is 177 Kg / 3.6 hours = 49.2 Kg / hour

Trip fuel remaining = 1.2 hours x 49.2 fuel flow = 59 Kg

Total Fuel remaining = 59 Kg Trip + 53 Kg reserves = 112 Kg

[Transalp787]

Thank you MAC. I was getting confused re the 130% bit. Cleared up now , cheers

[Mac]

Your welcome!