V1, V2 & Vr

[mr rowntree]

In my previous company we used these performance books and now since I came on to the Bus with this company we use a computer on board as I previously stated, I just presumed that all companies flying the 320 family used this method also, but as Roberto has stated his company use the printed book method.

I was told that the reason my company and a lot of other UK companies use the Laptop on board is because the computer can calculate the performance needed more accuratley than looking on graphs etc and therefore it can usually give us a de-rated thrust setting (FLEX) of around 1 degree hotter and therefore improve engine life, now 1 degree didn't sound much to me either but take this across a company operating the aircraft up to 12 sectors per day and this can make a huge saving!

Thanks to Roberto for filling me in on his companies methods, there are pictures on Airliners showing the laptops some companies use!

Regards

Rowntree

[bindook]

What i'm doing at the moment is ok as i make vr about 160kts.......& i haven't crashed yet....so i will just keep guesssing



Michael

[dodiano]

Well we don´t use the laptop cause the speeds are printed in pur weight and balance Sheet which is calculated by the dispatch system, the books we use it in case or a Runway change... Ok I will have to say if you are Full Load on an A-320 Something like V1-138,VR-145,V2-150 should do the trick I´m guessing here.

Take care,

Roberto

[NigelD]

Hi Guys...
There is a small free tool I use to calculate these speeds for Airbus. However since it is not working right now (registry issues on my computer) and I want to broaden my knowledge - how the devil can these speeds be calculated by a dummy?! I fly the (increasingly unsatisfying) Wilco Airbusses. Usually 321 and 330-200. Some charts are included with the aircraft in a PDF, but they don't seem to add up. The figure I believe is supposed to be Flex jumps in tens....that seems like too much to me?

Also...what does the Flex figure mean? I understand it's a derated t/o, but what is the difference in real terms between Flex 35 and Flex 40?

Nigel.

[Michael Carter]

I don't know what that Flex figure refers to, but performance charts in the POH will help you calculate your V-speeds.

The problem is finding a POH for newer aircraft.