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CPL performance final test Q23

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(@user5146)
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Hi when calculating the minimum fuel to be carried for Echo conducting a charter flight for question 23 in the final test. my calculation is 80x1.1+40.8+8.16=136.96(137)
The book states it is 80+40.8+8.16=128.96(129)
Looks to me like the answer in the book doesn’t include the 10% variable reserve required for a charter flight.



   
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Bob Tait
(@bobtait)
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Joined: 16 years ago
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I'm not sure where you are getting your numbers from.

Trip fuel = 80kg
So minimum fuel at take-off = 80 x 1.1 + 41 = 129kg (That's adding the 10% variable reserve and the fixed reserve of 41kg)

There is no need to add the 8kg taxi fuel since you are dealing with the fuel on board at TAKE-OFF.



   
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(@user5336)
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Hi Bob
This question not say anything about the AC T/O or Start. I think I have to consider the taxi fuel weight when the AC start and taxi for calculate the maximum weight for AC so still think need consider 3 G fuel before add any payload.



   
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Bob Tait
(@bobtait)
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It doesn't matter whether you check ZFW at take-off or at start-up. For example, if you check at take-off, you would use the take-off weight and subtract the fuel on board at TAKE-OFF.

You you check at start-up, you would use the START-UP weight and subtract the fuel on board at START-UP.

So, if the take-off weight was 2800kg and the fuel on board at take-off was 200kg, ZFW would be 2800 - 200 = 2600kg
If you check at start-up, you would simply add the 8kg of taxi fuel to both weights. So at start-up...
It would be 2808 - 208 = 2600.(Same answer).



   
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(@user5336)
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Sweet
Thanks. Another question about the fuel calculation. The scenario as follow:
One AC is a searching AC. From A to B to conduct the 30 minutes searching board task. How to calculate the minimum fuel at take off? Is the trip fuel add fix fuel add searching fuel? Is any requirement for variable reserves? This flight is private flight?



   
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Bob Tait
(@bobtait)
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According to the regulations, a search is considered aerial work (AWK) so no variable reserve is required. However, remember that a particular operator's operations manual may still require that a variable reserve is required on ALL flights undertaken by his/her company.

So it's a case of read the question carefully. The best way to approach this type of question is to begin by finding the trip fuel available by stripping all reserves from the total fuel at take-off. If a variable reserve is required, take it out at that point.

If a variable reserve is required Trip fuel (Total fuel at TO - fixed reserve) ÷ 1.1
If a variable reserve is not required Trip fuel = Total fuel at TO - fixed reserve.

If you then subtract the transit fuel (usually given), you have the fuel available for the search.



   
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(@user5336)
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Thank you for you patient.
One thing still confuse me is the answer of final test Q.23 as follow
MTOW is the least of:
T/O limit: 2950
LDG+burn off: 2680
MZFW+ all fuel:2762

There said the MTOW is 2680. But I think it should be 2762 bcs LDG+ burn off should be 2725+80=2805



   
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Bob Tait
(@bobtait)
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Where are you getting 2680 from? The book answer is "Landing wt + burn off = 2725 + 80 = 2805."

[attachment=1547]Q23.png[/attachment]



   
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(@user5336)
Active Member Customer
Joined: 15 hours ago
Posts: 6
 

My book is wrong. It confuse me too much. Do you mind send the correct one to me. Appreciation.



   
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(@user5473)
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Joined: 15 hours ago
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Given:
Runway-07/25
TODA-1500m
Surface-Long wet grass
Slope-1% down to SW
Wind-070°M/18kts
Temperature- +25°
Take off weight-980kg

What is the minimum takeoff distance required under the conditions given?

I'm confused its either 1433mm or 1471mm . I understand its about accuracy tht way seeking for y'all help.

Kind regards.



   
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Bob Tait
(@bobtait)
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Joined: 16 years ago
Posts: 2538
 

I can't check this for you because you haven't given me a pressure height.



   
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