You’re working as the air traffic controller at Remote Valley Airport on a misty night. Tomorrow is Christmas and the last three flights are approaching to the airport before this remote airport is closed for the Christmas. All three planes are nearing your landing strip with a difference of just few minutes, but trouble hits – your radar equipment has gone blank. Your only link to the pilots is through radio communication.
The Problem
Latest reports from intelligence warn that one of the three incoming planes has been hijacked and is under the control of hijackers. However, it is not known that which of the three planes has been hijacked. The hijackers plan to take the plane to another destination after refueling. The authorities need to send the hijacked plane to a nearby secure airstrip, now controlled by military, so a rescue operation can take place. In addition, the hijackers are listening to every radio message and will do anything to avoid being discovered before refueling.
The Restrictions
- No Visibility: The fog is too thick to spot the airplanes.
- No Radar Access: You can’t rely on your identification system—it’s completely down.
- Clever Opponents: The hijackers are smart and will try to act like normal aircraft.
- Urgent Timing: All three planes must receive landing instructions soon.
- Passenger Safety: You cannot endanger the lives of those on the other two planes.
- Communications: Use only the radio to talk. You cannot use secret channels.
The Problem
How do you figure out which plane has the hijackers, so that you can redirect it to the military airstrip.
Your Challenge
Come up with a way to make the hijacked plane give itself away without asking , “Are you the hijacked plane?” Remember, the hijackers are listening and might expect obvious tactics.
Can you figure it out before the planes run out of fuel?
— View the answer —
It’s obvious that hijackers are just coming to the Remote Valley Airport for refueling. As their plane is low on fuel for their next destination, they must replenish before taking off again. Therefore, a simple message to all the approaching aircrafts can work:
“The refueling operation has suspended on Remote Valley Airport due to fuel unavailability in Christmas holidays. The planes who urgently need refueling may land on the airstrip at the east at a distance of 15 nautical miles (Fly heading zero Niner Zero, 15 nautical miles).”
The Logic Behind It:
- Regular pilots would turn down the offer as Remote Valley Airport is scheduled to be closed for operations and they are not scheduled to travel anymore. Also, they do not want to face any refueling delays in the Christmas holidays for the passengers. They can easily refuel after Christmas holidays before they are scheduled to travel.
- Hijacked pilots, on the other hand, would be forced to land on the military airstrip as the hijackers plan to take off to their new destination immediately after refueling.
Thus, the hijacked plane would land at the military airstrip for refueling and rescue operation will be arranged accordingly.
