Great work. Job well done! Thank you very much.Now, some questions. What are the advantages or disadvantages of a packs on or off takeoff? Why would you do one or the other?Thanks again,GCP

Packs and anti ice use bleed air from the engines therefore less available thrust. If it's very very hot and or the aircraft is fairly light you may consider a packs on T/O for passenger comfort. But normally the few minutes on the T/O roll and initial climb is enough for everyone down the back to handle without aircon. If your desperate you could do a packs to APU departure.Rob

Thanks very much again Saturn_V for all the hard work :DJay V.

Thanks a lot for all the work you have done with this table Saturn_V, this is really appreciated! :( Christian

Bryan,this is great stuff!Thank you very much :(

Superb! :( Thank you very much

Amazing job, Thank you very much Bryan! :(Yahav Lipinski

Wow, unbelievable. Thank you!!!

Cool thanks. I've been using a .tod for UTOPIA I hacked together, now I'm going to use charts!!! I like charts better too. Hmmm, wonder if the printer works ....Tim Dobrowolsky

I do have a .tod for PW engines derived from the FAA runway requirement charts. However it's flaps 25 only. It's been working nicely. I don't know how to post it to the library, but I can figure that out if anyone is interested. (Also I have a .tod for the tinmouse too!)Tim Dobrowolsky

Who (or what) descides what flap setting to use anyway? I mean...the combination of flaps with FLEX descides the TO thrust. So.... I can choose whatever setting from the tables just as long as I use the settings form the correct weight...right?The question then is...why should I choose for flaps 28 instead of flaps 22?

Bryan, I have said this once before, and now it is my pleaseure to say it again... thank you for taking the time to put this together... a whole community stands behind you with one almighty pat on the back...A beer for you if you are ever in my neck of the woods, central Germany :)Andrew

Thanks again, much appreciated, great job.

Thank you guys!

Who (or what) descides what flap setting to use anyway? I mean...the combination of flaps with FLEX descides the TO thrust. So.... I can choose whatever setting from the tables just as long as I use the settings form the correct weight...right?The question then is...why should I choose for flaps 28 instead of flaps 22?

Well, the answer is

Who (or what) descides what flap setting to use anyway? I mean...the combination of flaps with FLEX descides the TO thrust. So.... I can choose whatever setting from the tables just as long as I use the settings form the correct weight...right?The question then is...why should I choose for flaps 28 instead of flaps 22?

Generally, you want to take off with the least amount of flaps as is allowed by speed/weight/runway restrictions. Remember, flaps will (up to a point) decrease your takeoff roll, but will also decrease your climb performance. So, if you can take off with less flaps, you're less likely to hit cumulo-granite at the far end should it be there :)That said, I believe most companies have a recommended flap setting for *all* takeoffs.In the real world, companies give their crews charts for each runway at each airport the airline services. That chart specifies a flap setting, and gives maximum weights you can depart with at a given temperature. Called a runway analysis...here is an example I Googled for a Gulfstream departing runway 34 in Zurich... http://www.flygp.se/images/airport_analysis_large.jpgYou can see, the G5 is not weight restricted departing 34 in Zurich unless it is a wet runway with a 10 knot tailwind and +35C, conditions not likely to ever be encountered. These charts also give V-speeds for each condition.

Seems all airlines are quite different in flap settings, in the Martinair video the Cpt says they always use flaps 25 except some flights where a optium setting may be warrented. Other sources I had read they always use flaps 15.