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Safe Endurance With Variable Reserve

  • Posts: 45
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Sofeopka created the topic: Safe Endurance With Variable Reserve

Greetings all,

I'm a bit puzzled, page 28, CPL Navigation Book, ordered new from Bob Tait about ten days ago.

I keep coming up with Trip Fuel available 135 litres and safe endurance 180 minutes. Or if calculated a slightly different way Trip Fuel available 132.75 litres and safe endurance 177 minutes. I'm not sure if this is correct.

Am I correct in thinking that variable reserve is NOT included in the Trip Fuel?

I'm stumped on why Trip Fuel available of 155 litres is divided by 1.1? I'm hoping this is a typo and should be 1.15 or something else?

I have included a photo of the page.

Thanking you in advance and looking forward to your reply.
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  • John.Heddles
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  • ATPL/consulting aero engineer
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John.Heddles replied the topic: Safe Endurance With Variable Reserve

First, CASA keeps changing things faster than the rest of us can change clothes from day to day. How Bob and Stuart manage to keep up with the changes, considering the number of documents they have to keep updated, is quite beyond me - but they certainly appear to do a pretty good job.

However, no-one is perfect and things manage to slip through from time to time.

The "old" variable reserve was 15%, the "new" is 10%.

This question is an example of the devil's being in the detail. The question asks for 15% but then, unfortunately, runs the calculation at 10%. No doubt, when Bob/Stuart see this thread, the error will be corrected quickly. The 1.1 factor should be 1.15 for it to be consistent with the question detail (oe else the detail needs to be changed to reflect current practice).

Am I correct in thinking that variable reserve is NOT included in the Trip Fuel? - correct - the reserves are added

I'm stumped on why Trip Fuel available of 155 litres is divided by 1.1? I'm hoping this is a typo and should be 1.15 or something else? that's for the crux of the matter on this occasion - the two factors are inconsistent

Engineering specialist in aircraft performance and weight control.
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Stuart Tait replied the topic: Safe Endurance With Variable Reserve

Well I don't know how that one slipped through it's so obvious never the less I'll amend that page to reflect the correct percentage

Cheers
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Sofeopka replied the topic: Safe Endurance With Variable Reserve

Thank you John and Stuart, I appreciate your responses.

I totally agree with you John, Bob and Stuart do a great job keeping up with the constant changes.

Thank you kindly.
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