How many times are aircraft carrier arrestor cables used?

As far as I know, the answer could be anywhere between once and hundreds of times. But does anyone have a real idea of how many stops they get out of a particular arrestor cable?

The Wikipedia article says they get pulled out of their housings when grabbed by an aircraft. Are they reloaded, or replaced with new?

I was in the Navy, but not on aircraft carriers, so take this with a grain of salt.

Anyway, the full statement in the article is: “The aircraft then pulls the cable out of its housings, against tension provided by a hydraulic mechanism that decelerates and stops the aircraft.”

The cable is not detached from the hydraulic mechanism. Picture the ends of the cables attached to huge hydraulic shocks. When the aircraft comes to a halt, the cable is simply retracted back.

It’s my understanding that cables are reused many times (i.e. hundreds or thousands of times), but I don’t know for sure how often they need to be replaced. They are certainly used more than once.

They change them at the same interval bungee jump cords are changed. Every time they break.

The arresting cables are attached to a large hyraulic-like piston (located on the deck below the flight deck). This piston offers the resistance needed to slow a fast moving heavy aircraft down in a few hundred feet. Nothing “comes loose”. The cable remains attched to the arresting gear throughout the whole process.

After the planes tail hook is disengaged from the cable, the cable is retracted (at about walking speed) back into the ready position by the arresting gear, and the tension is set for the next aircraft.

The USN currently uses the Mk7 system, I think. It is strong enough to stop 50,000lbs moving at 120mph. (Source is U.S. Aircraft Carriers by Norman Friedman, appendix C, pg 381. Unfortunately, he does not state what the expected life span of a cable is.)

Here’s a decent overall description of a carrier. There is a couple illustrations near the bottom to help illustrate the arresting gear:

http://www.globalsecurity.org/military/systems/ship/cv-design.htm

I found Stephen Coonts book The Intruders to be be very informative about carrier flight operations (and a good read overall). Though it is a fictional book, he includes a lot of background detail. He explains the arresting gear in great detail as a prelude to a situation.

I would expect them to be changed before that!, not only having a plane whoosh across the flight deck unimpended would be a problem, but also a snapping cable would turn the nearby ship crew into the whole cast of one legged pirates for the next swashbuckling film.

Flight-deck operations are dangerous. The crew know how to act, to protect themselves from such danger. And there’s a reason a pilot jams the throttles on his or her aircraft wide open as soon as they hit the deck: They might have missed the cables, or the cable(s) may have parted.

The USN has been doing carrier landings for a ong time now - they know what they’re doing.

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On preview, what Tranquilis said better than me :stuck_out_tongue: But remember there are 4 arresting wires, a correct landing snags the 3rd wire. So if a cable does snap, there’s a good chance another will be caught.
One point though is aircraft are parked abutting the landing zone, so a snapped cable could cause much paperwork :smack: , so I’d reckon they would be checked/replaced reqularly. The cable gets bent around a sharp radius tailhook under a high load, which won’t be good for it. Also the cable is operating in a salt wire environment, which will be very harsh on cable, especially if there is any damage to it.
I really thought someone with carrier flight operational experience would of shown up by now, as it’s an interesting question. Are there any dopers who were/are on carriers? :slight_smile:

WHOOSH!

That was not the sound of an F-18 that missed the cables. :smiley:

Not that I would have had any reason to disrespect them before, but every new question on the boards makes me respect the Naval aviator more than before.

Landing at night, on a pitching rolling deck, aiming to catch the wire but throttling up as soon as you land in case you need to do it all again :smack:

I believe they hit afterburner.

When it’s desired to get an older, long-time desk jockey to retire from flying just tell him that he must requalify for night carrier landins. :wink:

I saw a show on the Military Channel about life on an aircraft carrier. Aqccording to that show, not only do they change those cables, they have drills on how fast they can do so. The magic number for traps was 100, after which the cable was changed. They also showed film of a cable breaking during a landing and the damage it did as it whipped around. Dangerous job.

I was part of ships company, USS Ranger, from 1986-1989. Unfortunately, I was a computer tech, and not an airdale.

I remember from my time on the Nimitz that folks said 100.

Of course, I was in the engine room and not on the flight deck, so that number wasn’t nearly as important to me as, say, the flow rate of the reactor coolant pumps.

I speak from no direct knowledge or experience, but lighting the afterburner seems a bit dramatic to me for this situation. A near empty F/A-18C weighs on the order of 24,000 lbs, and can generate ~36,000 lbs of thrust with the afterburner. Even if the extra thrust is some fraction of that maximum, it seems like a lot of stress to put on the arrestor wires, not to mention the danger of igniting that much fuel mere feet from the surface of the deck.

USS Ranger

I was on the Harry Truman a few weeks back and I seem to remember that I was told that a cable would be replaced about once a week during deployments. I would guess that would work out to about 100 landings, but I’m no expert.

Link to said video. One guy jump-roped the cable as it came towards him. Very quick on his feet!

When I was on Kitty Hawk I heard rumors that there was this mythic place called the flight deck where people could sometimes see the sun and sky. Strange people them, us snipes didn’t trust that tribe known as the “air wing.”

Damn passengers was all they were. Expect us to drive the ship wherever they wanted so they could play with their fancy aeroplanes.

So you never got your Air Warfare pin after senior-in-rate, SW and your PPWS quals? Sissy. :wink: How else could you pass the time on a long boring deployment?

I was told that maximun catches per cabled varied (see below), but that 100 traps was where they started looking seriously at the cables. But that number could be and often was exceeded during extended flight ops. 100 is just the target. Each cable was rigorously inspected before landing operations were started for breaks, and I kinda-sorta remember a method of testing the cables with a machine instead of waiting for a plane to snap it.