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Beetle Diagram

• Posts: 26

shreyasrawat created the topic: Beetle Diagram

Hi guys,

I have come across Q23 in the Practice Exam 1 of the book where the landing limit + fuel burn off is showing as 2680kg.

I thought the max landing weight for the Echo is 2725 therefore shouldn’t the calculation be 2725 + 80 (trip fuel)?

I still ended up with C which was correct but the calculations don’t match the book. Therefore the flow chart in the book will have different numbers. Have I done something wrong?

Thanks

• Posts: 2121

bobtait replied the topic: Beetle Diagram

I'm having trouble finding that question. Are you referring to the Performance Book? If so, what is the page number?

• Posts: 26

shreyasrawat replied the topic: Beetle Diagram

Hi Bob
Yes this is from the Performance book and it is page 259.

• Posts: 2121

bobtait replied the topic: Beetle Diagram

You are correct. The answer given in the test is correct (220kg) but the working on page 259 is completely crazy. Don't know where that came from! Anyway, it's fixed now. The flight is ZFW limited and the cargo is 220kg. Thanks for your feedback. It is much appreciated.

• Posts: 26

shreyasrawat replied the topic: Beetle Diagram

No worries, glad I could help

I have another question regarding ballast fuel. For example, page 174 question 3. I noticed that you have added 30Kg worth of sandbags in the nose locker even though we can add another 90kg until we reach MZFW. My question is even though we have only added 30Kg to the nose locker (limited by permissible load) is it also possible to add some weight to the rear compartment, Wing compartments and nose compartment before we start adding ballast fuel? Or is it recommended to just add whatever weight we can to one compartment and leave the rest to fuel ballast before it gets messy? Are there any restrictions to doing this?

Hope this makes sense
Thanks

• Posts: 2121

bobtait replied the topic: Beetle Diagram

Because the problem is that the aircraft is loaded beyond the aft limit, the only place to put hard ballast would be in the nose compartment or in Row 1. All of the other compartments are further back than the aft limit of 2680mm, so any weight placed in Row 2, Row 3, Wings or Rear would make the situation worse.

The only place hard ballast will do any good is the nose compartment since Row 1 already has two occupants.

• Posts: 26

shreyasrawat replied the topic: Beetle Diagram

Aha I see. Thanks Bob that has now helped me understand another thing to consider when solving. Thanks for the clarification.

• Posts: 26

shreyasrawat replied the topic: Beetle Diagram

Hi again Bob,

I feel I am confused with what happens to ETP if there is a wind.

On page 109, it says “if A wind exists, the ETP will move upwind from half way. My understanding by this is it doesn’t matter if it is a head or tail wind.

Then the answer on page 130 to question 9 says an ETP always moves upwind from halfway...so an increase in HW causes it to move toward the destination end I.e further away.

Then question 10 answer on page 250 says if a wind exists the ETP moves into wind from its half way nil wind position
Then the second paragraph says a tailwind causes ETP to move closer to the departure Aerodrome while a HW will cause it to move further away.

These all seem to contradict with what’s written on page 109 and parts of the other paragraph.

What is the correct explanation?
Thanks

• Posts: 454

Stuart Tait replied the topic: Beetle Diagram

if A wind exists, the ETP will move upwind from half way. My understanding by this is it doesn’t matter if it is a head or tail wind.

• Posts: 26

shreyasrawat replied the topic: Beetle Diagram

Thanks Stuart
I think my next question has slipped under the radar. Please confirm the following

when using ETAS on a CR3, if the following info is provided;

Wind 300M/20
TAS 180
FPT 340M
Heading works out to be 334M

Is the ETAS a difference between the heading and FPT (6) so then on the black band you would end up with and ETAS of about 179? With a HW component to 24knots so GS = 156?

Is this the correct method?
Thanks