How aircraft carriers launch and catch fighter jets

HostIt's kind of wild to think about a floating city in the middle of the ocean acting as a runway for jets that weigh as much as a small house. There's this one tiny piece of metal called a holdback bar that basically holds the whole thing together right before the jet gets tossed into the sky. I have been wondering how you even start to move something that heavy that fast without just tearing the plane apart.

GuestWell, the ship engines actually can't give the plane enough power directly to get it up to speed in time. The runway is just too short for that. So, the ship has to store up energy ahead of time. They use something called an accumulator, which is basically a massive high-pressure tank that sits there and drinks up steam diverted from the ship's nuclear reactors or the boilers. When it's time to go, they don't just let the steam flow out slowly. They dump it all at once in this huge, violent burst. It's essentially a giant cannon under the deck. Instead of a bullet, they have a metal piston hooked to the plane by a part called a shuttle. When that launch valve opens, the stored steam hits the piston with about several million horsepower in a single stroke. It's enough to take a sixty-thousand-pound jet from standing still to a hundred and fifty miles an hour in about two seconds.

HostBut if you just hit it with that much power, wouldn't the plane start rolling the second the steam touches it? It seems like it would be a slow start.

GuestThat's exactly what they have to avoid. If the plane starts rolling slowly at the beginning, it uses up too much of the deck and won't be going fast enough to fly by the time it hits the edge. So, they use that holdback bar we mentioned. It's a piece of gear that acts like a mechanical fuse. The plane stays totally still while the engines are at full roar and the steam system is fully pressurized. That bar is designed to snap only when a very specific, huge amount of force is applied. It makes the launch binary. Either the plane is at a total standstill or it's under maximum speed. Once that bar snaps, the plane is flung forward at full tilt so it hits flying speed before it runs out of deck.

HostSo you're basically being shot out of a gun. But getting back down seems even scarier to me. I have seen those wires on the deck, but they look so thin. How does a wire stop a jet without just snapping or pulling the back of the plane off?

GuestThe wire is really just the part you see on the surface. The real work happens deep under the flight deck in a room called the arresting engine. Imagine a massive hydraulic ram where the wire is wrapped around a bunch of pulleys and then hooked to a piston submerged in fluid. When the jet's hook grabs that wire, it pulls on a part called a crosshead that drags the piston through the fluid. But here is the clever part. As the piston moves, it forces the fluid through a set of valves that get smaller and smaller as the plane moves. It's like trying to squeeze water out of a bottle. The harder you pull, the more the fluid fights back. This makes sure the plane slows down at a steady, safe rate regardless of how fast it was going when it hit the deck.

HostWait, I heard something that sounds totally wrong. Someone told me that when the pilots land, they actually floor it. They go to full power the moment they touch the ground. That sounds like the last thing you would want to do if you're trying to stop.

GuestIt sounds like a bad idea, but it's the only thing that keeps them alive if something goes wrong. If that tailhook on the back of the plane misses the wires, they call that a bolter. If the pilot had their feet on the brakes, they would be too slow to get back into the air. They would just roll right off the edge of the ship and into the sea. So, the rule is, as soon as the wheels touch the metal, you push the engines to full military power. If the hook catches, the big hydraulic system under the deck is strong enough to stop the plane anyway, even with the engines screaming at full blast. If the hook misses, the pilot already has the speed they need to fly off the other end, circle back, and try again.

GuestIt's a system built on the idea that you can't trust the landing to work perfectly every time, so the pilot has to be ready to leave the deck as fast as they arrived.

HostThe holdback bar at the start and that surge of power at the end are doing the same job, really. They both make sure the jet is either fully committed to the sky or safely stuck to the deck, with no dangerous middle ground.