Movie made in the 70’s or 80’s. Saw this movie when i was a kid in the 80’s.
Hostages and their armed captives is what i can remember, save the ending which sticks out.
A guy takes a pilot at gun point and gets him to fly him over maybe land or sea. Not sure if it was a small plane or helicopter. The captor opens an envelope or package containing a test tube or similar, to the dismay of the pilot who angrily tells him not to open it. It seems to contain a virus as I understand it now, not when I was a kid.
So the pilot, who knows death is coming, plummets the vehicle to both their deaths to avoid the virus going widespread.