If the airliner deviates from the expected flight path and the discrepancy can’t be resolved between the airline crew, ATC, and the fighter pilots, the fighters will tell their HQ what’s happening. If the Powers That Be decide the airliner is being converted into an attack vehicle, it will be shot down before it gets to a big city.
Which is why we in the airline biz take passenger misbehavior very seriously. And take defense of the cockpit very VERY seriously. Even a drunk or nutcase with no terroristic or suicidal intent could easily result in the loss of the jet, crew, and passengers if the situation gets out-of-hand enough.
With external tanks, an f-16 can carry 12,000 pounds of fuel. Density is ~six pounds per gallon, so that’s 2000 gallons. What does JP-8 cost per gallon, maybe $3? So max fuel load for an F-16 would cost around $6,000. Probably on par with an engineer’s salary.
That doesn’t count the maintenance, purchase price amortized over total flight hours, storage, and whatever other costs you can think of. Those costs far exceed the cost of fuel. Total operating cost has been estimated at anywhere between $7,000 per hour and $22,470 per hour, depending on who is doing the math.
Costs for other fighter aircraft surely vary, but are probably in the same order of magnitude.
Though it should be noted that maintenance costs for a fighter jet are far higher than for a passenger jet. Boeing’s numbers for the operating costs of the Boeing Business Jet, a modified 737, are mostly for fuel, as I said earlier. The other pro-rated operating costs in decreasing order are airframe maintenance, crew, engine maintenance, misc. supplies, and landing and parking. In Europe, however, the largest costs after fuel are navigation, and landing and parking costs are about four times higher than in the US.
A United Airlines 747 en route from Washington to Beijing, undoubtedly departing with near the maximum fuel load, returned to Washington about 3 and a half hours or so into the flight. Not a threat situation, but requested by the FBI due to a child abduction.
There was also a nearly 8-hour delay and a change of crew, with probably downstream side effects. I really think when there is intentional criminal activity like this involved, the perp should be on the hook for the full cost.
I suspect the cost, above what they would have spent anyway, is little or nothing.
My understanding is that pilots need to spend so many hours per week/month/year whatever in the air basically training. You would suspect that these cases would count toward that amount (can’t imagine why they wouldn’t). So whatever the cost of the escort is would be just that much less out of the training budget.
Getting the plane off the ground doesn’t do much toward actual training for a fighter pilot. That’s about as much training as a fire fighter driving to work.
The ROI is very low for an intercept. It’s not that the cost would not have been spent as much as money wasted that won’t be gained back. They fly on a budget.
I’ve read elsewhere that nylon zip ties are, just for that purpose. The shoe bomber was restrained with Duct Tape that a passenger had in his carry-on, IIRC.
My wife was on this flight, which diverted to Shannon, Ireland.
As noted in one of the comments below the story:
El Al had to fly their own security to Shannon. The passengers were bused from the airport to local hotels, where they stayed for several hours. In addition, this incident led to delays for other El Al flights out of New York. (We knew some people on that flight as well.)
I imagine all of this this must have cost El Al a pretty penny.
We carry restrain kits that have zip tie style handcuffs in them. There’s a set in the flight deck and a set in the cabin. The flight deck set is useless because we’re not permitted to unlock the flightdeck door if there’s any kind of disturbance in the cabin.