Originally Posted by Fly Me To The Moon

I have had three same-day returns pre-COVID. It has been hit-and-miss whether I get back on the same plane for the turnaround. The purpose of each trip was to go landside, to sign or deliver a document, and then to hop back on the plane for the turnaround.

One time, I was successful; twice, I was not. On these two occasions:

• one was when the HKG-XMN flight was delayed arrival, but when I got to the check-in counter to check in for the return flight, the counter had closed. In the pre-COVID days, Dragonair had more than one daily flight to Xiamen, so I would need to wait for the next departure.
• one was when the HKG-XMN flight was on-time arrival, but I ran into a long line up at immigration, and the check-in counter had closed for the return flight.

I believe that you do have to go through immigration upon arrival in Xiamen. I never did see any transit counter where I could just get back to airside without going through immigration.

I would not want to attempt a same-plane turnaround now, since CX is only once-daily for most days of the week, and I would not want to get stuck overnighting.