How would you react if you were on a flight where a family was boo'd for being allowed off the plane first to receive their soldier's body?

The best way to deal with people like that is ignore them. You only admit their existence and you reinforce the behavior.

I would let those people off the plane first, 10 minutes before landing.

This is kind of a BS question for this website I would think all the people that are in this website support the military

attempt to drown out the Boos in some fashion

Ungrateful!! Nor worth having a battle of wits with an unarmed person.

I would LOUDLY demand silence and respect, and if they were not given, I'd probably react confrontationally, and quite possibly VIOLENTLY.

I'd give up my seat and thank the family.

Sit in silence until the fallen soldier's family was off the plane and if I was close, I'd call them an ungrateful asshole.

As soon as the family had left earshot, I would give the disrespectful, Joseph N. Welch's words to Senator Joe McCarthy at the Army-McCarthy congressional hearing, "Have you no sense of decency?" Then shake my head and turn away.

To shame the person boo'ing I would stand at attention and render a perfect salute. If the boo'er would be stupid enough to make more sarcastic comments I would then offer to allow the person to join the deceased.....if you know what I mean! If they threw mw off the plane for that I would go with my head held high.