Markus Brunner has a utility in the library known as AI Contrail which parses aircraft.cfg files, modifies the temperature at which contrails are generated in FS9 by the plane, and can alter which effect file used for the contrail. Ken Salter's FS9 Configurator will also alter the temperature for contrail formation in *all* aircraft, Markus' allows selection of aircraft by engine type. That aside:The length of the contrail is determined within the effect file by a duration parameter, which can easily be modified. If proper data is available for conditions aloft, really just relative humidity or dewpoint, and of course temperature, and an average vapor pressure can be calculated along the path of an imported flight plan, and an based on saturation, an estimation of the duration contrails will persist, and below what temperature they'll form could be made. I'm wondering if in some future version of AS2k4 if it would be possible for AS2k4 to make the changes for you...since the processing of the flight plan yields averages for things like winds aloft, maybe it wouldn't be so far off to figure an average dewpoint aloft...I'm sure it's not worth the effort, but I though I'd share the idea. I don't even know if data for dewpoints aloft is available.Thanks for reading,sg

Good idea.JimActiveSky Supporthttp://www.hifisim.com/images/as2004proudsupporter.jpg

Thanks, Jim.;)

I had thought about this...but I think a problem is that the files are parsed when FS starts up, not during runtime...So any utility:1) would have be run before MSFS2) could only set the effects once...if weather conditions change it won't be able to do anything about itBut I would like to see something like that also.

Let's (and by let's, I mean you guys ;)) combine all the utilities - AI contrails, Ken's FSAutostart, and AS2k4. Start AS2004 and load or download your weather. Load and process the flight plan. AS2k4 calculates an average temperature/dewpoint at cruise, estimates a temperature at which contrails will form and their persistance, modifies the value set in all aircraft.cfg with user-defined engine types, and sets the duration in the effect file. After that is complete, the program launches FS9...Just a thought - nothing I could ever accomplish, but maybe someday it'll happen!Best,sg

Why not? Also combine the water waves direction ? AS2004 knows the direction of the wind , the wind generates the direction of the water waves ....and why not the hight of the waves ......let's dream a bit!I like it !

I had thought about adding an option to FSAutoStart to specify whether or not a program is launched BEFORE starting FS9 or AFTER. But I had not seen a program that needed to be launched BEFORE yet.There is definitely no problem adding this to FSAutoStart. I can make it launch, then pause. The user can do whatever they need to do, come back to FSAutostart, press a key, and the process continues.Any thoughts?btw, funny sig line from dubwa!

>btw, funny sig line from dubwa!It's amazing to think he's really a 'polished' public speaker now - he's got a ton of great quotes from his governership: "By not succeeding, we run the risk of failure." I may vote for him again just for the entertainment...like value added in some deviant way.RE: FSAutoStart - A pause between another app and FS - that might be a nice option. I think the data isn't there yet from AS2k4 for even manually setting contrails, but someone might find it useful elsewhere... Even having the ability to d/l weather, exporting it to FSBuild, planning the flight, then exiting FSBuild and starting FS, or something to that effect, all lauchable from a single UI. That's nice!Best,sg