AIR & SPACE MAGAZINE

The Complex Choreography of Carrier Landings

“Hook and release” is not as simple as it sounds.

Roger Mola

May 20, 2015

The cross-deck pendant (arresting wire) on the USS *John C. Stennis* is retracted below deck by the purchase cable and arresting engine, but to ensure it sweeps smoothly across the flight deck, it’s guided by U.S. Navy Seaman Willtavius Ward and Seaman Wyatt Steen.

Even an Olympic sprinter couldn’t beat an F/A-18C Hornet. But as this aircraft touches down on the *Nimitz*, Boatswain’s Mate Vanzel Simmon, a hook runner, bolts alongside and then straight for the tail, ready to manually pull the hook off the arresting wire if it does not disengage on its own.

Below deck, Boatswain’s Mate Brock Puffett on the USS *John C. Stennis* cuts a cable with a high-powered saw and a specially forged blade. Arresting wire and purchase cable, which have a breaking strength of 205,000 to 215,000 pounds, are made of steel strands twisted around either a polyester core or oiled hemp.

Today’s carriers have digital readouts, but on the USS *Midway*, a World War II-era ship that served until 1992, the dial on an arresting engine shows that the basic principles have changed little. The length a piston travels within the engine is marked in inches on the inner dial, with a target of 183 inches, or 15.25 feet. Ideally the aircraft should come to a stop at about 340 feet of cable runout, as seen on the outer dial.

Arresting engines below deck absorb the energy of the landing, stopping the aircraft nearly instantly but smoothly. Airman Jose Pintor is calibrating an engine on the USS *John F. Kennedy* for the next recovery, based on the weight and speed of the next aircraft to arrive—information that has been transmitted to him from the arresting gear officer.

Tailhooks on Navy aircraft typically extend about eight feet, and consist of a mostly hollow but strong tube that curls under at its tip. This hook was inspected by a final checker before the F-14D Tomcat launched from the USS *Theodore Roosevelt* into the Persian Gulf.

Once the aircraft is powered down, the tension in the arresting system usually makes it roll backward a few feet and the tailhook drops away on its own. If it does not, this sailor on the USS *Carl Vinson* needs to duck his head under the searing hot tail and unsnag it by hand.

An arresting wire does not lie flush with the flight deck but is elevated from 2 to 5.5 inches with a flexible length of metal support called a leaf spring. The extra height makes it easier for a tailhook to catch the wire without dragging on the deck’s surface. These sailors are changing a spring on the USS *Nimitz.*

Arresting wires like this one, on the USS John C. Stennis, connect to the purchase cable with a loop, and the purchase cable runs below deck to the arresting engine. Molding a new cable connection used to require heating zinc until it became molten at 1,000 degrees, but the Navy is testing an automated hydraulic press to “swage” the pieces.

An F/A-18C is trapped by the arresting wire. As the tailhook catches, the pilot applies afterburner to ensure that the airplane has enough power to make an emergency takeoff if necessary. This landing took place on the USS *Harry S. Truman* in the Gulf of Oman.

On an aircraft carrier the only task as important as landing an aircraft safely is preparing for the next one due in 45 seconds. That’s why the recovery cycle begins before the current aircraft rolls to a stop.

Most people seeing an F/A-18 Hornet landing a few yards ahead will not feel an urge to make an all-out sprint towards a roaring jet. Yet that’s the job description of a hook runner. After the F/A-18 snags its tailhook on the arresting wire, the pilot powers down and the tension from the wire releases, typically causing the Hornet to roll back a few feet until its hook falls away. If the tailhook doesn’t disengage on its own, the hook runner ducks under the searing tailpipe to pull it off by hand.

The arresting system can be reset in as little as 35 seconds.

Today’s arresting gear can recover aircraft that are faster and heavier than any in Navy history, but the interval between landings of 35 to 60 seconds has barely nudged from the era of piston airplanes. Last year when the F-35C Lightning began landing trials on the Nimitz-class carrier, Lockheed said it met the “perfect interval” of 45 seconds.

In August, the unmanned X-47B and a piloted F/A-18 Hornet were catapulted off the deck in quick succession and flew a pattern around the carrier. The pair were recovered within a 90-second interval. A hook runner stood by for the unmanned X-47B but its software automatically retracted its tailhook, and the hook fell from the wire.

Beyond the immediate flurry of landings, the components of an arresting gear system take time and grueling labor both above and below deck to maintain, re-spool, reweave and replace.