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## More Questions!!!

• Mickyd86
• Topic Author

### Mickyd86 created the topic: More Questions!!!

Hi all!

Few more questions that I would like some clarification with if possible

- Item included in AMBIENT CONDITIONS but NOT FORECAST CONDITIONS used for working TKOF Perf?
P.H
Surface Wind
Temp
RWY Slope

I put Temp... Was contemplating between wind and temp, but choose temp...

Can someone plse tell me where to research this?!

NEXT.......

Finding maximum cargo that may be shifted from Wings to rear when the ECHO is loaded 14.1 I/U inside the AFT limit???

I tried every way to answer this question, with exception to the correct way

ANOTHER......

Wt of Pilot, Pax, Empty a/c and Bagg - 2462KG
Fuel @ TKOF - 100gals
Flight fuel to first LDG point - 35gals

Ignore Balance considerations

No lim's on RWY length's

Determine maximum wt that my be carried in the rear compt of an ECHO a/c in flight?

As it said to ignore balance considerations, I just did the beetle diagram and came up with MTOW of LDG + Burn = 2820KG
For some unknown reason I did as follows:
2630KG - 2462KG = 168KG

And (which now seems waaaayyyy to easy) thought that because the rear limit is 155kg, then that looked like the best answer out of the 4! Completly wrong!

-55KG
-219KG
-155
-86

I think thats it for now!

Cheers

Mick

• Posts: 1169

### Richard replied the topic: Re: More Questions!!!

Hi Mick,

Here we go:

Ambient and Forecast conditions in relation to performance are defined in CAO 20.7.1 . The wind is what is left out of the forecast conditions to be used in the P-chart. That makes sense since you can't really count on a forecast wind being present when you arrive. If you had relied on that wind while calculating if it was safe to land, you might be up for a rude surprise when you got there!

Shifting weight:
This is a shifting weight problem and you would use the flow chart solution described on page 5.37 and 5.38 of the book. The shift required is 14.1 IU, CofG required is the aft limit of 2680 and you would use a difference in arms of 1450 (Arm for Rear compartment - Arm for wing cargo compartments)

As for the question on max weight in the rear cargo compartment (Q32 in CPL Perf Final Test I assume), the flight is landing weight limited at 2820 kg as you calculated. That means you can't take-off weighing more than 2820 kg otherwise you will exceed your maximum landing weight when you arrive at the destination.

So, your current take-off weight is a combination of your ZFW (2462kg) and the fuel on board (100 gals or 272kg). That is a total of 2734 kg. You can take-off with 2820 so the amount of extra baggage you can take is (2820-2734) or 86 kg.

If you want, you can double check that the extra cargo doesn't put you over your zero fuel weight limit: 2462 + 86 = 2548 which is less than 2630 kg.

Cheers,

Rich

• Mickyd86
• Topic Author

### Mickyd86 replied the topic: Re: More Questions!!!

Hi everyone!

Just want to send out a big thank you to Rich for his help during my studies for the dreaded Perf exam. Your words of wisdom helped more than you realise!

So I sat the exam this morning, and am very happy to say I walked out with 96%

Great feeling to get a pass in the subject and my best mark to date!

1 more to go!....

• Posts: 1169

### Richard replied the topic: Re: More Questions!!!

Brilliant mate!!! So pleased for you, Mick and 96% for Perf by homestudy is a very tidy result. Well done!

Good luck with the next one and if we can help, just give a shout

Cheers,

Rich

• Mickyd86
• Topic Author

### Mickyd86 replied the topic: Re: More Questions!!!

Thanks mate!

Am so happy at the moment!!!
Was not expecting such a good mark. All of the study DID pay off!!!

Last one is Nav Will get cracking on it later this week! Will be sure to post any questions I have regarding the subject on the forum.

Thanks again Rich!

Cheers Mick