The USS Nimitz (CVN 68) recently achieved a unique record. One of its four steam catapults made its 100,000th launch. That's after 34 years of operations. Normally, it's a big deal of a carrier reaches 100,000 catapult launches overall. Six years ago, the USS Theodore Roosevelt (CVN 71) did that after 17 years of service. The Roosevelt averaged some 500 aircraft takeoffs a month since entering service. In practical terms, the average is closer to 900 a month (about 30 a day) when deployed, because the carrier spends nearly half its time in port or going through periodic overhauls. During intense combat operations, there can be nearly a hundred catapult launches a day.
These catapult launches are dangerous, although fatal flight deck accidents happen very rarely, about once or twice a year. There are nearly 100,000 aircraft catapult launches a year on U.S. carriers. By way of comparison, the navy loses several dozen sailors a year to off duty motorcycle accidents, and more sailors are lost to other types of accidents (like falling overboard).
When on duty, especially on the flight deck of a carrier during takeoff and landing operations, there is a fanatical dedication to safety. New sailors, assigned to the flight deck, are not allowed out there for at least two weeks, as they are first drilled on all the safety procedures. These must become instinctive. To that end, officers and petty officers (NCOs) keep a close eye on the new guy for weeks after he is allowed on the flight deck.
When active, the flight deck of a carrier is a very dangerous place, and whenever a sailor dies on the flight deck, the incident is intensely scrutinized to find out if procedures, equipment or deck layout can be changed to make another accident less likely. The layout of the new class of U.S. carriers, now under construction, will be markedly different from current carriers, partly because of lessons learned from these accidents.