The Question states:
An Echo has 300litres of fuel on board at start up. If the flight fuel required is 120litres, how long could the aeroplane plan to hold at the destination aerodrome if holding is set at 35% MCP?
35%MCP = 17.2gph
300litres/3.8 = 79gals
FF = 120/3.8= 32gals
my working is as follows
(79-3-15)/1.15=53gals
FF=32gals
Remaining=53-32=21gals@17.2gph= 75minutes
your working is
32*1.15+15+3=55gals
Remainding=79-55=24gals@17.2gph= 84minutes
Both are very similar answers and could cause problems in the exam.
Should i always multiply the variable reserve and add all reserves/taxi to the flight fuel then subtract that total from the fuel on board at start up?
The exam is soon and i feel it will be pretty tough so Im just hoping to receive some feedback from someone with regards to what method i should use?
Cheers!
In your working you have allowed for 15% of the total fuel on board [79 gals]. You only need to carry 15% of the flight fuel. So:
Minimum fuel required is 32 x 1.15 + 15 + 3 = 55 gals.
Fuel available = 79 gals.
Fuel available for holding = 24 gals.
@ 17.2 gph = 84 minutes.
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Thanks bob, totally understand now 🙂
I totally forgot that the holding fuel due to being over destination doesn't require the 15% variable reserve 🙂
Guess I'm just stressing because the big day is tomorrow 🙂
Thankyou 🙂
