A3XX Hard to maintain V2+10 on climb

[Guest speight]

Hi Rob,I'll email you.I have almost produced my figures for different rwy lgths and will attach it to you tomorrow.I have not found any thing to say what is the min rwy for take-off except something in the AOM that said one stat mile, so have done lengths starting at that and up to 13000ft(Paris CDG). Just need to check figures and tidy it up. It should be useful in helping out with a few figures.Howie

[Guest vrandar]

I've done tests tonight at Hamburg EDDH of actual takeoff distance at varying flex temps but with everything else exactly the same. The first few results are below but still need to be confirmed. I'll cross check my results with your figures. I have also done some calcs based on figures I had in my A320 FCOM of the effect of higher runway elevations. I'm flying up to Glasgow tomorrow morning and back on Thursday night so it will probably be Friday evening or Saturday morning before I can send out a spreadsheet to youFLEX N1% ATOD mtrs Temp QNH Test Info-10 96.1 978 2 996 iFDG A319-11 96.0 983 2 996 EDDH Rwy 23-12 95.8 988 2 996 Dry-13 95.6 993 2 996 ZFW 50.0-14 95.5 998 2 996 Block Fuel 6.6-15 95.3 1003 2 996 TOW 56.4-16 95.2 1007 2 996 -17 95.0 1012 2 996 -18 94.9 1017 2 996 -19 94.7 1022 2 996 -20 94.5 1027 2 996 -21 94.4 1032 2 996 -22 94.2 1037 2 996 -23 94.1 1042 2 996 -24 93.9 1047 2 996 -25 93.8 1052 2 996 -26 93.6 1056 2 996 -27 93.5 1061 2 996 -28 93.3 1066 2 996 -29 93.1 1071 2 996 -30 93.0 1076 2 996

[Guest speight]

Looks like your figures match mine very closely Rob. I am looking forward to this table, keep up the good work.Howie

[Guest speight]

Did you get my email Rob, with the table in? I could maybe post it here?Hows your table coming on?

[Guest vrandar]

Hi, yes I did thanks. But I've been delayed in Glasgow (and am having to write this in the hotel on my ipaq) and won't be back home where the flightsim is until later today. I'll reply properly as quickly as poss.

[Bill McQueen 0]

Thanks for all the Info Speight and Vrandar,What a wealth of info you 2 guys have !!!Keep up the good work :-beerchug

[nooon 21]

To all :Thanks for the tip (FLEX temp -42

[Guest acva076]

Hello,The discussion of PSS and flex input was brought to my attention by your colleague Jaime. This is Jana Kankesan, developer of Tomaflex, once again here to add my two cents worth.The figure I have attached below depicts what I found with N1 output, based on OAT or pilot chosen FLEX TEMP.http://forums.avsim.net/user_files/109759.jpgAs you can see from the graph, PSS flex system is flawed when OAT is typical lower than ISA + 15C. That is, if you are in cold temperatures, inputting a flex temp which theoretically should be within ISA+15 and ISA+40, you will get N1 that is surprisingly higher than TOGA.Here is why?Refer to the graph, and follow examples I have given below.Example 1:Lets assume that OAT is 30C, ALT is 580 ft.If you use TOGA, you will get 102.0% N1.If you use FLEX TEMP 40C, you will get 100.5% N1.This is reduced thrust working as it should.Example 2:Lets now assume that OAT is 0C, ALT is 580 ft.If you use TOGA, you will get 98.0% N1.If you use FLEX TEMP 40C, you will get 100.5% N1.You are now getting more thrust with FLEX TEMP, which is exactly where the flaw lies. Therefore, you have to use much higher temperatures to get reduced thrust in cold OAT, which is not how it should be.The problem is simple. The FLEX TEMP N1 should be adjusted for OAT, but it is not in the PSS A320s. Once again, it is because of this flaw, I decided to program Tomaflex. It takes into account the flaw and gives you numbers that aren't too rediculous, but at the same time, numbers that will allow you to carry reduced takeoffs.As far as I have investigated thus far, only PMDG 737-800 and -900 have been programmed to accurately calculate reduced thrust.Hope that helps.Questions and comments always welcomed.Kind regards,Jana Kankesanwww.tomaflex.net