Sailors, jets rely on carrier's four wires to prevent a disaster while landing
By BROCK VERGAKIS | The Virginian-Pilot | Published: July 5, 2016
ABOARD THE USS HARRY S. TRUMAN (Tribune News Service) — The margin of error aboard a floating airport is razor thin.
The only thing stopping a $57 million fighter jet from disaster when it lands on the USS Harry S. Truman is a carefully choreographed routine, four steel cables – each about 1½ inches thick – and a team of about 50 sailors that makes sure the wires catch it.
Planes approach an aircraft carrier at about 150 mph. That allows them to take off again if their tail hook doesn’t grab one of the four wires placed at 20-foot intervals near the ship’s rear. Pilots aim for the third wire because it’s the safest to approach. They have only a few seconds and about 330 feet of runway to stop before either taking off again or crashing into the ocean.
“I think anytime you’re operating on an aircraft carrier flying high-performance jets, you’re taking quite a bit of risks,” said Lt. Cmdr. John Hiltz, an F/A-18 pilot aboard the Truman. “I mean, we see accidents and tragedies happen in military training in the States.”
One of the risks is the arrested landing gear, which is a system of flight deck cables, steam engines and sheave dampers that pull an aircraft to a stop. Cable breaks on the flight deck are rare, but they can maim those nearby.
“Once it’s snapped, it will do that slingshot effect,” said Chief Petty Officer Cesar Cobossabano, an aviation boatswain’s mate who ensures the system’s engines work. “Coming back, it will do some damage to the airplane, maybe kill some people. It’s pretty bad.”
Eight sailors were injured in March aboard the USS Dwight D. Eisenhower when a cable broke as an E-2C Hawkeye was attempting to land. Six of those sailors were flown to hospitals in Norfolk and Portsmouth. The Navy has not released details of its investigation into the incident.
Eight people were injured in 2003 when an arresting cable broke during an F/A-18 landing on the USS George Washington. As the cable snapped back, it struck a flight deck coordinator in the head and the jet fell into the Atlantic.
The arrested landing gear has two systems of cables. One is on the flight deck, which is called a cross deck pendant. It is 110 feet long and has to be replaced after every 100 landings, or “traps,” as the Navy calls them. A new one can be installed in as little as 60 seconds.
The other system of cables is attached to the steam engines underneath the flight deck; they are called purchase cables.
Those cables pull a movable part of the engine that travels along greased skids and pushes a giant piston into a cylinder full of pressurized hydraulic fluid. The piston compresses the fluid, bringing the wire on the flight deck and the aircraft to a stop. The engine operators ensure the equipment remains at the correct temperature and pressure.
“All the pilots, they put all their trust on us to make sure that these engines are right,” Cobossabano said.
Chief Petty Officer Cesar Cobossabano examines an engine beneath the flight deck of the USS Harry S. Truman on June 13, 2016 that is part of the arrested landing gear that pilots use to land on the aircraft carrier. The Truman is operating in the eastern Mediterranean Sea in support of Operation Inherent Resolve. Photo was taken aboard USS Harry S. Truman during its mission in Mediterranean Sea.
Brock Vergakis | The Virginian-Pilot
The engine room is hot and extraordinarily loud when a jet clutches a wire. Crew members inside constantly monitor the engines, sensors and wires and perform maintenance on them. It’s not glamorous.
The 1,150-foot-long engine wires also have to be replaced about every 1,200 traps, which can take 24 to 36 hours.
So far this deployment, Navy aircraft have landed on the Truman about 9,000 times.
“It’s hard work, it’s long work. And we try to teach them how important it is to maintain this equipment,” Cobossabano said. “As you see, every 30 seconds we’re taking a trap.”