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Mickyd86 created the topic: Finding MTOW
Just going though the Perf book and am up to fuel ballast on the good ol' Echo
Am currently on Exercise 5.10 (1) and have a question regarding MTOW and finding it using the 'beetle' diagram.
I understand majority of it (I think!!!), except when it comes to doing the calculations at the end:
MOTW least of-
Point B + Burn
2630 = all fuel at T/O
My question is in regards to when you use the '2630 + all fuel at T/O?'
It seems that some questions appear to drop that one and only require you to find the lesser of the first two...
Why is that?! May be a pretty straight forward question but I can't get my head around it at atm!
If the question is asking for the maximum CARGO you can carry, you must consider three possible limits separately.
1. The maximum weight permitted at the departure aerodrome.
2. The maximum landing weight permitted at the destination plus the weight of flight fuel.
3. The maximum zero fuel weight permitted, [2630kg] for the ECHO, plus the weight of all fuel at take-off.
The smallest of these is the maximum weight for take-off for that particular trip.
However, when the question asks for the maximum FUEL that can be carried, the examiner has to give you the weight of cargo, passengers and the empty aircraft and pilot. In this case you know the actual zero fuel weight and the examiner has to make sure that it doesn't exceed the limit of 2630kg.
So when you are asked to find the maximum FUEL that can be carried, you only need to check 1. and 2. above. On the other hand, if you are asked to find maximum CARGO that can be carried, you need to check all three cases.