The scramble horn wailed and F15s from Otis Air National Guard Base on Cape Cod screamed into the air. It was September 11, 2001. The mission that day was jarringly simple, “Identify, divert and if no response, be prepared to shoot down."

The country was under attack. My other employer, United Airlines, had lost one airplane and another had been commandeered by terrorists. Other than that, no one knew what was going on. My task was to find United 93 and neutralize it. Did I know any of the pilots on board? Had I worked with any of the flight attendants? The time for these questions was an eternity away.

Almost nine years later, we know that the heroes of Flight 93 selflessly overtook their captors paying the ultimate price. Most likely, you won’t find yourself in such a dire situation, but if you are “intercepted” by an F15 there are effective measures you can take as a passenger to aid the crew.

There are several reasons a civil airliner may be intercepted by a military fighter jet. Make no mistake, though, this is not a normal occurrence. Typically, fighter jets are scrambled to divert aircraft that have wondered near restricted airspace, have missed radio check in and reporting points, or are in distress. From a passenger’s perspective, you most likely will not know why your airplane is being intercepted. No matter the case, you as a passenger will be alerted something is abnormal when you see a fighter jet so close to the left wing of the airliner that you can see the eyes of the fighter pilot inside. The jet will slowly fly past you from the rear and take a position on the left side and slightly high. You will not see the other fighter jet in a "support" position, but he is there. Next, the fighter jet will gently rock its wings to say, "You have been intercepted." In response, the airliner will rock its wings. These are standardized, established and universal procedures. Believe it or not, before September 11, F15s could not communicate directly with airliners because they used radios with different frequency capabilities. That issue has been resolved. As a passenger, understanding the mindset of the fighter pilot and the airline pilot will help determine your response, if any.

Intercepting a civil airliner is not an everyday occurrence for a fighter pilot. It is a dynamic environment and coordinating airspace, keeping track of fuel, accounting for the weather; authenticating orders and maintaining situational awareness combine to make what should be a simple intercept anything but simple. Rest assured, an intercept is an extremely safe maneuver. The F15 pilot will know if the aircraft is in distress or is a threat. If the aircraft is crippled, the fighter pilot’s job is to aid in any way he can by providing visual inspections or helping the airliner to a divert airport. Here’s how you can tell your situation from your airline seat. If your aircraft is experiencing a problem, hopefully the Captain has told you. Typically, the only time a fighter will scramble to intercept an aircraft in distress is due to an electrical problem or a navigation problem. From your window, see if the airliner’s exterior wing lights are on. Also, check to see if the "fasten seatbelt" or other interior lights are on. If they are not, you may have an electrical issue. If it is a navigation problem, you probably won’t know, but with today’s technological marvels of navigation, redundancy usually prevents these sorts of catastrophic problems. Sometimes, a fighter jet is scrambled to be an extra set of eyeballs for the airline crew if there is a fuel or hydraulic leak. In this case, you will be able to see the fighter jet fly in a cylinder around your airplane ostensibly checking out the location and severity of any leak. The mindset of the airline Captain is completely focused on the safety of the crew and the passengers.

Checklists and procedures abound and the Captain will communicate with airline mechanics on the ground, the FAA, and even aircraft manufacturer engineers to ensure you get on the ground in one piece. During any aircraft problem, the Captain will turn on the "fasten seat belt" sign to clear the aisle. Expect the flight attendants to go back to their stations at the front and rear of the cabin and take out their checklist to prepare the cabin for a potential emergency landing. If you see this kind of activity, it’s best to sit tight until the Captain comes on the intercom and explains the situation. Review the safety card in the seatback that you didn’t review before you took off! Take solace in the fact that the civil airline industry is among the safest operations known to man. On the other hand, if you have reason to believe your airplane is being assessed as a threat, you must react differently.

In a threat situation, the fighter jet will act pretty much the same. From its position high and on the left side of the airliner, the fighter pilot will evaluate the situation. Once the wing rock dance has been offered and responded to, you may see the fighter jet gently turn into the airliner to get him to turn away from his flight path. A turn from the airliner signals the Captain understands the situation, acknowledges the intercept, and is control of the airplane. Again, expect the "fasten seat belt" sign to illuminate. Also, if there are no overt signs of problems in the cabin, the flight attendants will return to their stations and begin their security procedures. Under no circumstances will the crew open the cockpit door. The flight attendants should move the food carts in the aisles to block movement. As a passenger, if you see a fighter jet next to your airliner rocking its wings and don’t feel any response or movement in the cabin, reach up and ring the call button to tell the flight attendant. Believe it or not, it is difficult for the flight attendants to see out of the windows when they are standing in the aisles. The sight line is just too low. They can call to the Captain and let him know. If there is movement in the cabin and you perceive security in the cabin is compromised, realize there may be Federal Air Marshals on board.

Depending on the threat, they may or may not act. If they act, you will know! Fasten your seatbelt and put your hands either on the arm rests or on the seat back in front of you so you look as non threatening as possible. If they don’t act or there are none on board, it may be up to you. Flight attendants probably will enlist the help of passengers rather than try to neutralize the situation themselves. Some items you can use to subdue unruly passengers are blankets, duct tape, purses, keys, and items in the airline medical kit. One of the most effective tools is the onboard defribulator – it will leave a mark! Use the phone to notify authorities if possible or just leave an open line off the hook. Brief a plan to those around you and act. The goal is to overpower the perpetrators with overwhelming force. Even if they have been certified to carry firearms in the cockpit, these are to defend the flight deck primarily, so don’t expect the cockpit door to open. It is always good to ask if there are any other pilots or flight attendants not on duty but on the plane.  They have specialized training to help in these situations. Have the passengers not actively subduing the bad guys signal to the fighter jets by raising and lowering the window shades. This is easy for the fighter pilots to see from their vantage point. If this occurs at night, use a flash light or the light from a cell phone to signal since the fighter pilots will most likely have night vision goggles on. Any kind of response from the cabin will help the fighter pilots assess the situation. Use phones in the cabin and the intercom system to the flight deck to communicate that passengers are trying to regain control of the cabin. As soon as the situation is resolved, notify the Captain and tell him to notify the fighters.

Being an observant passenger on your next airline trip could mean the difference between life and death. Seeing an F-15 pull up alongside your airplane can be quite disconcerting, but understanding why they are there and what they are thinking will help you become a part of the security of the crew rather than just a person along for the ride.

Editors Note:

You can find Mr. Martin’s book Scrambled here.