To have smoke in any aircraft simply go into the aircraft you want to have smoke in and click on the CFG file and under radios and add

[SMOKESYSTEM]
smoke.0=-10.00, -0.70, 0.0, fx_smoke_w

and make sure there are spaces inbetween like it is now.
but be carefull when you use it because somtimes there is a glitch and you can not turn it off.

And also do not use smoke in when in a circut without permission of the tower, host and/or other players unless you can not turn it off.

have a nice flight.
cya.

jamie.