Does anyone know for sure or have a place on the web to where I can read if turboprops do actually leave contrails in the air?I have been wondering about that an am not sure of myself. Usually seems to be a jet. But never really stopped to think that at the altitude it is at it could very well be a turboprop. Thanks,

TProps and even piston props can leave contrails. There's one shot of an Avanti at airliners.net that clearly shows a contrail. As for piston props, numerous pictures taken during WWII show contrails of fighters, bombers, etc as those aircraft flew in the flight levels.Since you posted it in the MSFS forum, I suspect you're curious if contrails can be added to these aircraft types. The answer is yes--there's a new aircraft.cfg parameter which determines the temp at which the contrail appears--just search the default 737 for the word "contrail". You can paste this line into any FS9 aircraft.cfg, and instant contrails.I am afraid in FS2002, contrails were only avail for the jet aircraft model, and only appeared above FL300.-John

Theoretically a contrail can be produced by any aircraft with an engine. The conditions for a contrail to be produced are relient on the ambient temperature and humidity of the air and the temperature and humidity of the exhaust from the engine.The question of whether a contrail will be produced can be found using a tephigram which shows a temperature, pressure, humidity profile of the atmosphere.During WWII these diagrams were used to determine the height above which a contrail would be produced, thus making the detection of an aircraft easy. The pilots were given the height below which they should fly in order to avoid producing a contrail. This height was determined using the MINTRA line on the tephigram, which can still be found on current tephigrams used by the UK Met Office.Regards,Jon

Wow that is quite interesting...Hey thanks for the knowledge gents...

I have a post here called "Gridley's guide to contrails" - some links in there you might find informative. http://forums.avsim.net/dcboard.php?az=sho...ing_type=searchI plan on updating the info regarding how to add different contrail effects to the different types of aircraft in FS9 to use the new 3D contrail effects in the library, but I have no time right now...maybe in a week or two.Best,sg

> I have a post here called "Gridley's guide to contrails" ->some links in there you might find informative. >http://forums.avsim.net/dcboard.php?az=sho...ing_type=search>>I plan on updating the info regarding how to add different>contrail effects to the different types of aircraft in FS9 to>use the new 3D contrail effects in the library, but I have no>time right now...maybe in a week or two.>>>Best,>sgHey Mr. Gridley, Thanks for that will check it out.