In London Has Fallen, which I've seen today, after the terrorists attack the USA President (from now on I'll just reference him as President), the President escapes the ground by using a helicopter, while being surrounded by two other helicopters.

After one of those helicopters (helicopter #3) gets shot down by a missile, the two remaining realize they're being targeted by the terrorists firing missiles from the rooftops of the buildings, so they start doing their escape thing and releasing air-missile anti-measures. After they run of anti-measures, helicopter #1, which holds the President, tells the helicopter #2, which is the only remaining escort helicopter the following: "Helicopter #2, prepare to sacrifice.", to what the pilot (or whoever) of helicopter #2 simply says "Copy.", in firm, but indifferent voice - and seconds later, the helicopter #2 is being blown to pieces. So, the helicopter does the same thing Secret Service agents are trained to do on the ground, take a bullet for the President, but instead of the bullet, the helicopter and people inside it take a missile, and all die.

Is this, another helicopter taking a missile for the President, what would actually happen? My guess is yes, although, the part that I doubt would happen is the "Copy." part, in a indifferent, calm voice. Even though all the Secret Service agents are trained to take a bullet for the President, only four have ever done so.