Most people think of tailhooks as something only carrier aircraft need. Then an Air Force F-16 with a hydraulic failure lands at a normal land base, drops a hook from under its tail, and snags a steel cable stretched across the runway. Seconds later, the jet is stopped.

Land-based fighters have been using arresting cables for decades. At many air bases, and even at some civil airports shared with military units, a cable system such as the BAK-12 sits quietly across the runway, ready for the day a jet has no brakes, a blown tyre or a problem that makes a normal landing too risky. Here is how it works.

Why a Land-Based Fighter Carries a Hook

A fighter lands fast, and it relies on its wheel brakes, and sometimes a drag chute, to stop on the runway. When something goes wrong, such as a hydraulic failure, a brake or anti-skid problem, a blown tyre or battle damage, the pilot may not be able to stop in the length available. An arresting cable turns that problem into a routine event.

That is why jets such as the F-15, F-16 and F-4 Phantom carry a tailhook even though they will never land on a ship. The pilot lowers the hook when a cable engagement is planned.

How the BAK-12 Works

The BAK-12 cable is a steel wire suspended about 2 inches above the runway surface by tension and rubber supports, so a hook can pick it up. Each end connects to a strong nylon tape. Staff Sergeant Jared O'Neill, a barrier maintainer at Joint Base Elmendorf-Richardson, described the tape to DVIDS as woven into a rubberised compound similar to the material of a golf ball.

The tape runs underground to a 66-inch storage reel in a shelter at each side of the runway, each with a 65-horsepower diesel engine to rewind it. When a hook catches the cable, the reels spin out and hydraulic brakes are applied progressively, soaking up the aircraft's energy.

An F-16 arresting cable test at Denver airport. Video: AIRBOYD

The Crews Behind the Cable

Arresting systems are maintained by civil engineer power production crews. At Joint Base Elmendorf-Richardson, according to DVIDS, the barrier team starts its daily checks at 6 am, inspecting hydraulics, fuel, pumps and leaks, with weekly, monthly, quarterly and annual inspections on top. Two airmen are on standby at all times, and after an engagement the goal is to reset the system within 10 minutes so the runway can reopen.

At Shaw Air Force Base, home of F-16 squadrons, the NCOIC of aircraft arresting systems, Staff Sgt. Callum Jantzi, summed up their importance to DVIDS even more briefly: if the barrier systems are not operational, the base does not fly.

Cables at Civil Airports

Arresting cables are not only found at military bases. Where fighters share a runway with airliners, such as airports with an Air National Guard unit, cables can be installed on a joint-use runway. The Aviationist has shown an F-16 catching an arresting cable at Tulsa International Airport, and the FAA publishes guidance on aircraft arresting systems at civil airports in Advisory Circular 150/5220-9B.

Airliners do not have hooks, of course. Their equivalent is a runway end safety area or a bed of crushable material that stops an overrunning jet. But for a fighter with a failed brake, a two-inch-high cable and a hook is still the simplest and surest way to stop.

A genuine F-15 emergency landing into the arresting cable at RAF Lakenheath. Video: Ted Coningsby

Next time you see a line of black rubber discs across a military runway, you are looking at one of the quietest safety systems in aviation.

A Portuguese Air Force F-16 during an emergency arresting cable test at Lajes, Azores. Video: IslandAviation Terceira Azores

Sources: DVIDS, Wikipedia (Arresting gear), The Aviationist, FAA