Page 1 of 1
ATPL Aerocourse : Need help with performance chart question
Posted: Thu May 24, 2018 5:41 am
by goose_68
hey Guys .... having a little trouble deriving the answer for a couple of questions from the ATPL aerocourse book .
In the Flight Operations and Human Factors section questions # 23 and 24 page 6-7 .
Anyone with some guidance on these with an explanation of the derivation would be greatly appreciated . Feel free to post or PM me .
Thanks
Re: ATPL Aerocourse : Need help with performance chart question
Posted: Sat May 26, 2018 5:43 am
by ozone
I am having trouble with those ones as well.

- IMG_6095.jpeg (252.05 KiB) Viewed 2108 times
Re: ATPL Aerocourse : Need help with performance chart question
Posted: Sat May 26, 2018 6:19 am
by goose_68
Thanks for posting that , if you find some insight on these 2 questions please let me know
Re: ATPL Aerocourse : Need help with performance chart question
Posted: Sat May 26, 2018 7:00 am
by 455tt
And of course you secured the advance permission of the publishers to post their copyrighted materials onto a public forum, correct?
If you have not, you should of course remove their materials immediately and ask them first.
As well, have you considered going directly to the publishers with your question - I am certain they would be more than pleased to answer your inquiry directly.
info@aerocourse.com
Re: ATPL Aerocourse : Need help with performance chart question
Posted: Sat May 26, 2018 9:24 am
by tired of the ground
They are quite straight forward de-rating questions. The temperature is a bit of a red herring, you don't need it when you know your GTOW.
All you do is take the GTOW of your aircraft and then look for the lowest climb or runway limit that is above your gtow.
Q 23. Your gtow is 30,500. For runway length you have the option of rw15 @ 81.8% (32,240 ft) or rw33 @ 77.2%(30,990ft). For the climb limit you are limited to 77.2% (42deg @ 30,760ft). You just have to determine what your limiting factor is. In this case both rw33 and your climb limit are 77.2% so that is your limiting factor.
Q24. Same idea. Just look at your GTOW. 33,150lbs, RW33 @ 83.3% (33,160) or RW 15 @ 92.0%(33,230). In this case off of 33 your are climb limited though, you have to look 1 row up to 84.1 (33,520) to meet the climb requirement.
Re: ATPL Aerocourse : Need help with performance chart question
Posted: Sat May 26, 2018 1:22 pm
by ozone
They are quite straight forward de-rating questions. The temperature is a bit of a red herring, you don't need it when you know your GTOW.
All you do is take the GTOW of your aircraft and then look for the lowest climb or runway limit that is above your gtow.
Q 23. Your gtow is 30,500. For runway length you have the option of rw15 @ 81.8% (32,240 ft) or rw33 @ 77.2%(30,990ft). For the climb limit you are limited to 77.2% (42deg @ 30,760ft). You just have to determine what your limiting factor is. In this case both rw33 and your climb limit are 77.2% so that is your limiting factor.
Q24. Same idea. Just look at your GTOW. 33,150lbs, RW33 @ 83.3% (33,160) or RW 15 @ 92.0%(33,230). In this case off of 33 your are climb limited though, you have to look 1 row up to 84.1 (33,520) to meet the climb requirement.
That clears things up.
Thanks very much
Re: ATPL Aerocourse : Need help with performance chart question
Posted: Sat May 26, 2018 3:52 pm
by youhavecontrol
455tt wrote: ↑Sat May 26, 2018 7:00 am
And of course you secured the advance permission of the publishers to post their copyrighted materials onto a public forum, correct?
If you have not, you should of course remove their materials immediately and ask them first.
As well, have you considered going directly to the publishers with your question - I am certain they would be more than pleased to answer your inquiry directly.
info@aerocourse.com
Pretty sure this falls under "fair use" as the person posting it is asking about the content for better understanding, and not distributing it in any way for commercial gain.
Re: ATPL Aerocourse : Need help with performance chart question
Posted: Sat May 26, 2018 4:28 pm
by 455tt
Could be - then again, maybe not. Seems prudent to me that you first seek the a copyright holder's consent before you openly distribute their materials online, whatever your motives. Especially when the copyright holder can so easily be contacted.
Re: ATPL Aerocourse : Need help with performance chart question
Posted: Sat May 26, 2018 5:04 pm
by goose_68
Thanks " tired of the ground "
The temperature portion was what was throwing me off . Most T/O performance questions I have dealt with in the past of course use temperature / altitude as the starting point .... this is little different then what i have dealt with
Thanks again