What happens during a carrier take off?
A carrier aircraft launcher is called a &quot;catapult&quot;, for good reason! It's job is to get an aircraft up to flying speed very quickly, which of course results in a very high acceleration for the plane and pilot. Sometimes as high as 4G.
On modern American aircraft carriers, the catapult is about 300 feet (90 metres) long, and can get a large plane up to flying speed, 140 knots, in about 2 seconds. By comparison, taking off on a conventional runway a plane might need 2 kilometres to get up to this speed.
As you can imagine this puts a lot of stress on the planes, carrier aircraft are built much more rugged than an aircraft that would only fly off normal runways.
Each catapult-launched aircraft has different procedures for launch. In the case of the F/A-18, the pilot keeps his hands off the control column during the actual launch, grabbing it as soon as the plane leaves the edge of the deck. This is not the case for other carrier aircraft, such as the C-2 Greyhound, nor is it the case when taking off the same aircraft from a runway.
I found this in the F/A-18E/F flight manual (PDF here):

Immediately after the end of the catapult stroke, the aircraft will rotate to capture the
12° reference AOA (hands-off). To avoid PIO with the FCS, do not restrain the stick during catapult
launch or make stick inputs immediately after catapult launch. The pilot should attempt to remain
out of the loop but should closely monitor the catapult sequence.

AOA = Angle of Attack, PIO = Pilot-induced oscillations, FCS = Flight Control System.
Which roughly translates as &quot;The F-18 will fly itself and find the optimal climb angle without pilot input during the launch.&quot;  This is not the case though for other aircraft.