You have to first load a flight with the C 172 (or any other default plane). Then press ALT go to Flights>Load then select the 767-300 ready to go at KSEA. Then go Options>Go to Airport> choose your airport.

Tatave wrote on Sep 25^th, 2012 at 1:41pm:
That is normal for the Captain Sim 767. You should try starting with the 767-300 Cleared for takeoff (KSEA), then move it to the airport of your choice. You can save it once you have done that, so you can start from that airport whenever you like.

Starting with the default C172 running, WILL NOT get the 767 to start. It will be shut down (cold-n-dark) as soon as you load the 767.

That is strange! When I do it, the 767 always starts up cold-n-dark.

Well... they do. Depending on your startup flight, they behave differently as they aren't really initialized but take FSX variables as they are. This is happening with the 777 and that's why each user has his own different issues with it.

I mentioned this long ago to CS, but it seems it was overlooked. It's important though... VERY important actually.

fsxking08 wrote on Oct 1^st, 2012 at 3:09am:

If I use a flight with the default C172 started and on the runway ready to take off, no matter whether I select the 767 and then press FLY NOW, OR press FLY NOW and then load the 767, the engines are always OFF.

I do not post much however, I will post this. All of my FSX experiences starts with a saved situation. I do not ever use the FSX start screen (disabled from day one). When I click on (start) FSX, it starts with the last situation I saved along with the conditions (variables) that existed at the time I last saved it. Whenever I want to start FSX with a situation, I go to my folder where situations are stored and select the title  "(named)".flt and modify my FSX.cfg situation line to reflect it and FSX starts with it.

I hope this helps . . . . . .