When fighter jets are scrambled to intercept enemy or unidentified planes, they have a range of options, from immediate lethal fires to trying to contact the rogue plane via radio, depending on the situation. One of the options is to use their plane to conduct the "headbutt" of the other plane.
The maneuver is sweet, but not nearly as metal as it sounds.
A U.S. Navy F/A-18E Super Hornet, like the ones that headbutted and then attacked and destroyed Syrian ground attack aircraft in June, 2017.
(U.S. Navy Mass Communication Specialist 3rd Class William Rosencrans)
There are a number of maneuvers which have been described under the umbrella of the term, "headbutt," but none of them include physical contact between the two planes.
Last year, the 'headbutt' maneuver got press coverage after F-18Es intercepted hostile ground attack jets over Syria in June. There, the U.S. fighters conducted one of the most aggressive forms of the maneuver. Two American jets flew close to one another, with one trailing behind. The jets' wakes combine and become even stronger, and the two jets fly in front of the targeted jet in order to destabilize it with the violent wake. They also dropped flares.
Basically, the two American jets use the "winds" from their own passage to rock the targeted jet. When that failed to dissuade the Syrian Su-22 from bombing U.S. backed forces, the F/A-18E shot down the Syrian jet.
(AirWolfHound, CC BY-SA 2.0)
Another version of the headbutt, usually seen when the Air Force is trying to get the attention of a friendly or civilian aircraft, has the headbutting jet fly well underneath the target aircraft, then fly up nearly vertical about 500 feet ahead of the friendly plane's nose, nearly guaranteeing that the pilot will see the U.S. fighter without forcing the pilot to fly though a violent or dangerous wake.
This is only done if ground controllers and the fighter pilots have been unable to establish radio communications with the aircraft, and the aircraft is flying into restricted airspace.
A third version of the maneuver is very similar to the first, but has only one jet flying ahead of the targeted aircraft. This has two advantages. First, less wake is created, meaning that the targeted aircraft is less likely to encounter trouble in flight as a result of the maneuver. Second, it allows the wingman of the headbutting aircraft to loiter either hidden or in a good attack position, ready to move in for a kill if necessary.
This version of the maneuver is often accompanied by the release of flares in order to drive home the point that the U.S. jet is trying to communicate with the targeted aircraft.
While these maneuvers have certainly existed for a long time, the American emphasis on them has grown since the attacks of September 11, 2001. Suddenly, an Air Force that had always been aimed at foreign enemies had to be prepared to assess threats in the domestic airspace much more often.
Like all U.S. military forces, especially when operating with and near civilians, the U.S. pilots wanted a clear escalation of force procedure with ways to assess whether a civilian aircraft was a threat before they were forced to shoot it down.
F-16s like this one can fly well over the speed of sound, but have to be prepared to slow down enough to communicate with civilian planes visually, whether its by headbutting them, rocking their wings, or flashing their lights.
(U.S. Air Force Senior Airman Kathryn R. C. Reaves)
This required the pilots to develop new skills, like additional levels of warning an aircraft that it was entering restricted airspace. It also led to pilots of fighter jets that could break the sound barrier suddenly being worried about how they could slow down enough to read a Cessna's tail number.
If that doesn't sound challenging, realize that many of the single-engine planes flying around U.S. skies are considered fast if they can clear 175 knots, roughly equal to 200 mph. Meanwhile, F-16s can fly 1,600 mph. If a fighter is checking on a slow-moving, single-engine plane, they may need to fly (at least) 100 mph faster than their target simply to prevent a stall.
Now imagine trying to get a phone number off of a yard sign while your friend is driving 100 mph.
But if they can't get into radio contact with a plane and can't properly identify it from its tail number, they still need options to get its attention without shooting it down. Headbutting, making radio contact, flashing their landing lights, and dropping flares are among such techniques, but they're not the only ones. In fact, in at least one tense situation over restricted airspace, a Coast Guard helicopter flew ahead of a civilian plane with a whiteboard telling it to change to a specific radio frequency.
Thanks to all these efforts, the U.S. Air Force has never had to shoot down a civilian plane, and they've gained experience using a valuable tool for deterring enemy planes near U.S. forces abroad. But, like the events in June 2017 demonstrated, the "headbutt" won't always scare the enemy away — and American pilots still might have to get their hands dirty.