We are flying into Bangkok via Cathay Pacific and catching a Thai Air local flight to Chiang Mai, which departs about 2 1/2 hours after our arrival.

We are a bit nervous about catching this Thai Air flight.

We are assuming that Cathay Pacific will fly into the new aiport. But we don't know which airport Thai Air will fly out of.

Please help shed some light on this new vs. old airport issue.

Thank you in advance for your assistance.

HPN

Only the new airport has flights. While there has been some talk of re-opening Don Muang for budget airlines, that has not happened.

As kathie has said, all thru the new airport Suvanrabhumi so no worries.

Thank you for your replies. Happy and safe travels to you and other readers out there.

Nothing to be nervous about Thai Airways. Don't really understand your question. Given the choice of cathay pacific or Thai Air, I would allways choose Thai Air. If you have any problems with your connection at Bangkok (arriving late for example), you will be treated with absolute courtesy and professionalism, which will result in your journey being completed with the minimum of hassle.
Sadly, the same could not be said if you were flying to usa.