FSX-MS Contrails Not Showing

[SoloPilot 2]

So... I was flying the PMDG 737-800 from Atlanta to Orlando. As I was climbing through 25,000 ft, I noticed that the plane was not producing any contrails. I checked the temperature, and it was at about -40 degrees celsius, while the Total Air Temperature was at -8 degrees celsius. Keep in mind that I typically see contrails at this point. Just to make sure that it's not the PMDG, I hopped into the F-18 that comes with the simulator at the NASA Shuttle Landing Facility (KTTS). As it turned out, that didn't produce any contrails either, even as I went up through 35,000 feet. I do not understand why the contrails would all of a sudden stop appearing, when they were showing up when I flew a few days ago.

I am using Active Sky Next and simulating real-world conditions.

[Jim Young 2,356]

Special effects turned on?

[SoloPilot 2]

Yes, the special effects detail is on high.

[astroavion 2]

I like using this file for contrails. Maybe this will work if you don't already have it?

Avsim library:

longer_contrails_fsx_fs9.zip

Here is another one:

aicontrails.zip

Andrew Grey

[SoloPilot 2]

Just to clarify: all my AI aircraft have contrails, but I don't for whatever the reason.

[Angels40 17]

It has been my experience that contrails can disappear if the Top Down view distance is set too high.   Maybe this is peculiar to my situation, but as soon as I zoom down to begin seeing the aircraft, the contrails mysteriously appear.

[Bjoern 1,153]

Contrails appear by default above 29000 ft and below -39°C, unless max_contrail_temperature in the aircraft.cfg is set to a higher value (e.g. -30°C).

See the contrail related parameters here: https://msdn.microsoft.com/en-us/library/cc526949.aspx