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Navigation Exceecise N.8a - I cannot get answers on page 30

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DARKMAIZE created the topic: Navigation Exceecise N.8a - I cannot get answers on page 30

I cannot seem to get Amy of the answers in the table on page 30.

The exceecise says to use 10% contingency, Final Reserve of 30 minutes at cruise rate and 8l taxi allowance..

Are the answers using 45 minutes reserve as required by part 135 despite the question stating otherwise?

Actually, even that doesn't work..
133 min * 55lph = 121.92L (122 - correct)
10% contingency = 12.2L
Taxi allowance = 8
30 min reserve = 27.5
= 169.7

If 45 min reserve: = 41.25
Total: 183.5?
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Stuart Tait replied the topic: Navigation Exceecise N.8a - I cannot get answers on page 30

G'day

I apologise about that table, I'm uncertain what happened there, but the fuel required at startup column is not even close to the right answers, I have updated the E-Text and have put up an Errata for the physical copy.

Here is the updated table.


Again sorry about that, sometimes things just get through the cracks.

Cheers
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merijngarry+BobTait@gmail.com replied the topic: Navigation Exceecise N.8a - I cannot get answers on page 30

Hello Stuart,

How are the numbers in the updated table correct? Looking at that second line:
55lph, 133min
Trip fuel = 55/60*133 = 121.92 (all good so far)
Trip + 10% = 134.112
Taxi: 8 + 134.112 = 142.112
45min res = 55/60*45=41.25
Total Trip = 41.25 + 142.112 = 183.36L

How do we get 170L?

The book dated August 2018 had 183 and that seemed to be correct.

Any help much appreciated.
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Stuart Tait replied the topic: Navigation Exceecise N.8a - I cannot get answers on page 30


Your correct, I have amended the table, don't know what happened there I got something messed up.
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merijngarry+BobTait@gmail.com replied the topic: Navigation Exceecise N.8a - I cannot get answers on page 30

Perfect thanks for that Stuart,

In that case the entire table is out of wack in the current online version of the book. The 'fuel required at startup' set seems to be miscalculated however the 'trip fuel' is looking good.

Thanks again for the amazing support!
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Stuart Tait replied the topic: Navigation Exceecise N.8a - I cannot get answers on page 30

I just realised that you have been using 45 min reserve and the question asks for 30 min, that is why your numbers are out.
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merijngarry+BobTait@gmail.com replied the topic: Navigation Exceecise N.8a - I cannot get answers on page 30

Yep my mistake I used the first line which still appears to be in error and an older text book to conclude a 45 minute reserved. Checked all the numbers and all look good for 30 min except the first line.

Again I could be wrong, I calculate the first line as.
35....206....41....158....32....120

Not
35....206....44....168....32....120

Sorry should have double checked the lines for 30 min after the first line to see if the numbers lined up again.

Just another quick one. Page 59 of the current online book under the flight data has 'Contingency Fuel 15% of Trip fuel required'. In the staircase calculation below it has 'Contingency fuel 10% of 7'. No issue in final number due to rounding.

Again can't thank you and the team enough for the training guides.
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Stuart Tait replied the topic: Navigation Exceecise N.8a - I cannot get answers on page 30

Yes your right about the first line, I can see what happened there the wrong cruise fuel flow was used.

35....206....41....158....32....120 is correct

I have amended the figure on Page 59 as well

Cheers
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