Hey all, bout to sit my last CPL exam, woohoo, and have a quick question for those who have already been successful in the all fun Performance exam. While going through the Bob Tait book, I've noticed he rounds figures to whole numbers etc. All well and good most of the time, but time's when using the flowchart to figure out weight to shift or remove etc. I have had quetions where I just run figures on along the calculator, keeping accuracy, and end with a result sometime's 10% off the answer in the back of the book, just wondering what method people chose in CASA'a exam.

For example, when using the Add/Subtract weight flow chart, I will find the COG, subtract 2680 from the exact figure while it's still in my calculator, multiply that exact figure by the present weight, then divide this exact number by the figure 'Arm subtract desired COG' (Already worked and rounded figure)

I use this method because it is quicker than finding the COG, rounding, writing the number down. Subtract 2680 from that figure, round it, write it down, etc.

Only using standard Aurora DT210 calculator.

If you try this out on page 5.41 fuel ballast example, you should get 50Kg, when the published answer is 44Kg, just due to a bit of rounding through the flow chart instead of flowing the digit's through on the calculator. Big difference in a CASA exam.

Don't know if anyone can really give ma deffinitive answer as to the best way of doing it, but if you used a particular way in the exam and passed those questions, would love some feedback, cheers.

Hi FTAB and Richard,

I just Section 3 for Fuel Planning. After failing miserably on the first attempt, I noted in the Quizzes for Fuel Planning I that the method used was to round the minutes to the nearest whole minute (makes sense) and to round the Fuel Flow to the first decimal. COOL..

Now I just did Fuel Planning II and the examples talk about Fixed and Var fuel amounts but the calculations are all rounded up the the whole Gal and not to the first decimal. WT???

What does CASA want for the exam?? Admittedly if the questions are "Multi-guess" then it will be easier, but in complex scenario type questions, a rounding here, a rounding there all adds up to a "0" for the question.

Please advise.

Here you go guys. Classic Example.

The exercises below from the On-Line Drills where the ALL the questions I rounded to the nearest minute and to the nearest full Gallon as directed.

that method works perfect for the first 4 BUT on the last question, the numbers are so close (144Kts and 146NM) that if you round to the minute you get it wrong. If you simply leave the minutes as an 8 figure number (all the decimals) you get it right.

Question 1
Marks: 1
Given the following conditions:

Distance
187 nm
TAS 130 kt
Fuel Flow 31.7 gph
Wind: 9 kt headwind

What is your flight fuel? Round your answer to the nearest gallon.
Answer:
Correct
SOLUTION:

Correct
Marks for this submission: 1/1.


Question 2
Marks: 1
Given the following conditions:

Distance
228 nm
TAS 154 kt
Fuel Flow 23.1 gph
Wind: 17 kt tailwind

What is your flight fuel? Round your answer to the nearest gallon.
Answer:
Correct
SOLUTION:

Correct
Marks for this submission: 1/1.



Question 3
Marks: 1
Given the following conditions:

Distance
245 nm
TAS 125 kt
Fuel Flow 9.1 gph
Wind: 18 kt tailwind

What is your flight fuel? Round your answer to the nearest gallon.
Answer:
Correct
SOLUTION:

Correct
Marks for this submission: 1/1.



Question 4
Marks: 1
Given the following conditions:

Distance
182 nm
TAS 125 kt
Fuel Flow 21.2 gph
Wind: 20 kt headwind

What is your flight fuel? Round your answer to the nearest gallon.
Answer:
Correct
SOLUTION:

Correct
Marks for this submission: 1/1.



Question 5
Marks: 1
Given the following conditions:

Distance
146 nm
TAS 151 kt
Fuel Flow 24.1 gph
Wind: 7 kt headwind

What is your flight fuel? Round your answer to the nearest gallon.
Answer:
Incorrect
SOLUTION:

Incorrect
Correct answer: 24
Marks for this submission: 0/1.

G'day,

I would normally recommend keeping the decimals in any intermediate steps and save any rounding off for the answer in the final step. After all, rounding the intermediate steps is just throwing away accuracy.

So, I would work these problems keeping the flight time in decimals and then using that to get the flight fuel required. This value could then be rounded to give the final answer to the nearest gallon.

This is also what I would recommend for the CASA exam.

Cheers,

Rich

Hi Rich,

Thanks

I noted some more Drills for conversions. Is it true to say if the question asks for an answer to 1 decimal then do that, but if it doesn't, then give a whole number?

Paul

Hi Paul,

Yes, round to whatever the question wants from you. By the way, in the CASA exam they usually use the phrase "is closest to...' which bypasses the rounding problem.

On another note, the drill exercises don't count towards your final mark for the online CPL-PERF course so don't stress about them too much. They are there to help you practice your calculation technique so you can repeat them as often as you want and the system will generate different values for you each time.

Cheers,

Rich

Hi Rich,

Understood and thanks.

(Hate seeing less than 100%)

Good attitude to have - as long as it doesn't keep you up nights

Obviously this was something I was a little worried about, hence starting this post. If it helps you relax I didn't have any issues with it at all in the exam, the answers were far enough part (Unlike Nav), that I could punch in my answers without any second thoughts or guess work.

Not sure of these drill questions you talk of, think it might be something new, but before sitting this exam late last year, I had studied the entire Bob Tait book, and had a crack at the cyber prac exams. I was a little worried about this exam, but I focused on the points I got wrong in the prac exams, went in prepared, and found the exam MUCH easier than I expected. Walked out with 100% and time to spare!

My point is simply if you put the work in, don't let these little things worry you, it's not a tricky exam at all. I had all units consistent (No sneakey mixed litres and gallons, kg's and Ib's etc), and no other traps. There were more traps in the Tait exams (Which prepares you well). My first 3 or 4 questions were almost straight out of the Aerodynamics exam, asking about take off roll with frost vs ice etc, I had done the aero's exam so was no worries, but they're only 1 markers and not too difficult to even guess right anyway.

Just keep your roundings to a sensible and practicable level, and if you end up between two answers, pick one of them, and note the question number, you should easily have time to go over it at the end of the exam being more precise.

Good Luck.

Good advice there - thanks for posting!

Cheers,

Rich

P.S. the drill exercises Paul mentions are in our online CPL Performance course.