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## Beetle Method Explanation - Additional Question

• Posts: 2

### jv2477 created the topic: Beetle Method Explanation

Hello All, I have a question about the beetle method when finding out the new MTOW to find max payload questions. Also apologies in advance if this question has already been answered, I am pretty new to the forums.

In some questions when working out scenario three (BEW + Total Fuel), all of the examples use 15 Gallons as Fixed Reserve (FR). But after looking at some of the explanation of some questions, the FR added is only 10 Gallons.

I have read and re-read the questions and no mention of part 91 vs part 135 operations within and struggled to find where the 10 Gallons instead of 15 come from.

Please see attached below of some of the working out.

Working out for Review Question Set 1 Q14 - Uses +10 Gallons instead of +15 Gallons for FR.

Jimmy

• Posts: 2469

### bobtait replied the topic: Beetle Method Explanation

The supplement says that the final reserve fuel is calculated at 20gph. The final reserve fuel is 45mins for air transport flights and 30mins for private fights. That might explain the variation in the working. Check whether the operation is private or air transport. If there is no mention of private or air transport it would be safe to assume (shouldn't need to) that it is air transport since the exam is for CPL.

• Posts: 2

### jv2477 replied the topic: Beetle Method Explanation

Hi Bob,

Thank you for your speedy response and dedication on the forums, I am finding many useful tips and pointers throughout.

I have looked at two particular questions again (Review Set 1, Q14) that does not stipulate if its a private flight (Assumed part 135) and also another with, 'Data for an air transport flight in an Echo.' (CPL Final Test, Q7). In both cases the worked explanations provide a difference of 10 USG from the trip fuel and total fuel at take-off.

I have attached the relevant Qs and As below for reference.

Not quite if I am again missing something :/

Kind Regards

Jimmy

• Posts: 20

### dontgiveup replied the topic: Beetle Method Explanation - Additional Question

Hi, I got questions on the worked answer for the Question 7 (p.237 - CPL Final Test) that you posted as well, and guess it would make the forum look tidier by appending my question here than if I make a new post on it.

1. Assuming the fuel of 85.2kg is correct, why an MTOW of 2735 kg is used in the flow chart instead of 2715.2 kg?
2. Why all fuel ( = Trip fuel x 1.1 + Final Reserve + Holding ) 85.2 kg instead of 105 kg?

I will re-attach the question and answer below for easy reference.

And if anyone knows the answer to the questions in the following pages, I would be forever grateful:
www.bobtait.com.au/forum/performance/731...ae-p-173-p-190#15094
www.bobtait.com.au/forum/performance/731...7-new-review-q-set-2

• Posts: 2469

### bobtait replied the topic: Beetle Method Explanation

I've checked out the questions you referred to (Q14 and Q7), and they both refer to an air transport flight. It's likely that the book has been amended since you obtained your copy. By the way, in the unlikely event that the CASA exam question does not specify private or air transport, you would be justified in assuming air transport since the exam is for CPL. Of course that should not happen in any case.

Bob

• Posts: 2469

### bobtait replied the topic: Beetle Method Explanation - Additional Question

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• Posts: 20