I have been in a situation where I boarded a plane without *any* valid visa.

<sup>(Long story, but it was a three-leg flight A–B–C, sold as a two-leg flight. The first two legs A–B shared the same flight number, same airplane, same boarding pass, same seat, but the second "leg" B was a domestic flight, so I had to go through immigration.)</sup>

My impression is that it is partly the responsibility of the airline to check the validity of the visa before letting you board. In my situation, I had to sign a form, saying that I would buy my own ticket out of the transit country, in case I couldn't proceed through immigration to board the domestic flight.

In your case, the airline probably has the right to deny you boarding the plane, but since they can see you have a valid visa 5 minutes after you are scheduled to arrive, **I would strongly suspect that they will let you board**. Their worry is to take a passenger, who will be stranded in the transit zone, because they don't have a connecting flight, nor a visa to pass through immigration (in which case they might be made responsible for taking them back).