Aircraft carriers’ catapults
Aircraft carriers are the centerpiece of America’s Naval forces – the most adaptable and survivable airfields in the world.
US Navy flat tops support and operate aircraft that engage in attacks on airborne, afloat and ashore targets that threaten free use of the sea and engage in sustained power projection operations in support of US and coalition forces. Aircraft carriers must be able to launch these aircraft in such a small space. With so much chaos in such a small area, engineers have had to design catapults, simple yet effective devices to help manage the process.
Getting air moving over the deck is important, but the primary takeoff assistance comes from the carrier’s four catapults, which get the planes up to high speeds in a very short distance. Each catapult consists of two pistons that sit inside two parallel cylinders, each about as long as a football field, positioned under the deck. According to How Stuff Works, the pistons each have a metal lug on their tip, which protrudes through a narrow gap along the top of each cylinder. The two lugs extend through rubber flanges, which seal the cylinders, and through a gap in the flight deck, where they attach to a small shuttle.
A catapult shot (or cat shot) usually generates up to 4 Gs and the airspeed will go from zero to 160mph in just two seconds.
Cat shot
Does a fighter pilot get used to G-forces when he or she is catapulted from an aircraft carrier?
Tim Hibbetts, former US Navy A-6 and F/A-18C pilot, explains on Quora;
‘You don’t get used to it. You don’t want to get used to it. It’s a thrill unlike any I’ve encountered and it’s already ruined roller coasters for me.
‘The cat shot is 2.5 seconds of unbridled adrenaline, sending a static airplane to fly-away speeds near 150 knots. The G-forces increase all the way down the stroke, from almost 3 in the first quarter second to around 4 by the end. It’s enough to change the shape of your eyeballs.
‘Most pilots rest their helmets against the head rest, but the only time I tried it, the thing vibrated so much, it rattled my teeth half out. So, I tense the neck and lean into it. The only time that backfired was in taking a “war shot” in the A-6. They needed to get us to over 170 knots, and the forces were much stronger, catching me off guard about half-way down, slamming my head back and ringing my bell. We climbed away fine, me with a big, stupid smile on my face, feeling foolish.’
Hibbetts concludes;
‘The nice thing is that the g-forces are transverse, so the blood isn’t fleeing from your brain like normal, turning g-forces. You’re just along for the ride. In the daytime, it’s glorious. At night, you’re hoping it’s only going to be harrowing. Suffice to say, it’s unlike anything else out there.’
Photo by Mass Communication Specialist 3rd Class Jonathan Snyder
