Contrails

[MajorMagee]

Do we have a way to set the contrail fx to only be on at certain altitudes?

[Willy]

I know how to do it in FS, but there it's outside air temperature related. It's been a long while since I poked my head into a CFS3 aircraft.cfg file. Is there a general engine section?

[greycap.raf]

There is but it's more than basic.

[GeneralEngineData]
engine_type = 0
Engine.0 = 7.9, 0.0, 0.0
fuel_flow_scalar = 1

[MajorMagee]

The Max / Min Vel function (same as for the wingtip vapor trails) works, but it's not what I'm really after.

Max / Min Alt doesn't appear to work, so I was hoping there was some other command available to do it.

http://i549.photobucket.com/albums/ii362/MajorMagee/P-38Contrails.jpg

[SLIP STREAM]

straight up no! but there is a program line in the config. file called, "critical altitude". this line tells the program to start cutting back on power and preformance,at the typed altitude..it's the only altitude trigger. i contacted o-1 driver around a year ago about trying to attach an effect to that config. line. thats as far as it got,and i have no idea how it could be connected to as a call up line. if anyone has an idea,try that line.it's in the general engine section.

[mongoose]

This has been an issue for some years without a solution re altitude. All people have found works is based on ac speed and try to keep either the speed below that one sets for the contrails to appear. This work Ok for bombers (B17) but no good for fighters who engage at high speeds at many altitudes. I asked about using mixture which is effected by alt but so far no one has proposed an answer. (There are lots of old posts, probably in the archives on this!)

[SLIP STREAM]

hey mongoose yes you asked about mixture as trigger a few times.this is the "mixture" trigger. it's what starts fuel/power cut back scaler, at the typed in altitude.it's the only line that controls a change dureing flight.

[Willy]

Okay, I got a peek into a CFS3 aircraft.cfg and there's a lot of similarity between it and FS9. More than there is with CFS2.

In FS I'd add this line to the general engines section:

max_contrail_temperature = -25 //Temperature (deg C) below which contrails may appear

If you want to try it, make sure you're flying in cold weather and at high altitude.

[mongoose]

Have you tried it ??

[MajorMagee]

It didn't seem to have any effect.

In any event I went ahead and uploaded the aircraft with contrails set for true airspeeds between 170 m/s and 200 m/s. Since we can't trigger the contrails based on altitude this is a close as I could get to restricting them to where they belong since it's generally difficult to reach these high speeds until you reach higher altitude without going into a power dive. Given a fullpower setting and a modest climb angle (5-10 deg), you get to 170 m/s true airspeed just about the time you reach 26,000 ft. To add a bit more visual variability, the contrails also get progressively thicker as your speed continues to increase from 170 m/s to 185 m/s.

http://i549.photobucket.com/albums/ii362/MajorMagee/P-38J-15-55thFS.jpg
P-38J-15-LO SN 43-28430, Assembled at Lockheed's plant in Burbank, California.
55th Fighter Squadron 20th Fighter Group, 8th Air Force
Based at Kingscliffe, Northants.
30 escort missions, 9 fighter sweeps, and two bombing raids were recorded for this P-38, with one enemy aircraft, two locomotives, and one torpedo boat destroyed.