Morning… me again 😉 this is more of perhaps a failure of my grasp of the English language… and yes… english is my first language… :() but I’m thinking that it’s not perhaps so much my ability to calculate the answers to the questions, but completely understanding WHAT it is they want me to do ….so in ex 5.10, it’s asking me to give them a max take off weight permitted, and the ballast fuel required in the main tanks…
So I’m ok and knowing how to find the ballast fuel for the mains, as they have given me the ZFW… and I use my flow chart to get to weight to add… but the max take off weight permitted?
The answer..p207 alludes that it is an echo… so why is the answer 2805kg…landing plus burn… I thought max t/ o of the echo was 2950kg?
And then too…why have they not included the ballast fuel in the TOW?
It does make things a tad easier were you to post the question as it is presented ? That way there is no potential for interpretative problems.
Engineering specialist in aircraft performance and weight control.
I think I may have just figured out my own question :~\ but I’ll post it and would still be very appreciative of help
Reading over a few times… I remembered that you have to take into account the landing weight hence the max TOW permitted…. Ahhh dear me…. As God is my witness.. I’ll get through this…or die trying … I’ve got a few years up my sleeve 😉
The two calculations are unrelated.
The ballast fuel required required is simply the use of the flow chart and you seem to have no problem with that.
The minimum fuel required is really a completely separate question and requires the use of the 'beetle diagram' as dealt with separately in the book.
This would not be an exam question, but I included it to show that it would not be impossible to find that, after the addition of ballast fuel, you could find yourself too heavy to land! Now that would drive you nuts!! It was included in the book just for fun.....
Hi Bob in this exercise, I’m getting wrong minimum fuel requirements. In Q.1 you have calculated 107.2. Page 207. But in my calculations if it’s a transport op, then 80x1.1+ 45min (57.12kg)=145.12kg.
If it’s a private op then 80+30 min(38kg)=118 kg. Same happens in Q.2 too. Am I missing something?
Thanks. Hossain
I don't know where you are getting 57.12kg for the final reserve fuel. The final reserve fuel for the Echo is calculated at the reduced rate of 20gph. That's 15gallons (41 kg). So min fuel (kg) = 80 x 1.1 + 41 = 129 kg.
