To do... what's the required Vspeed setting to determine catapult speed?
For Carrier Operations, one normally uses an aircraft that can be catapult launched from the carrier as well as the capability to do arrested landings.
To set up an aircraft in the simulation for a catapult launch from a carrier, simply select the "Special Take-off" menu, then click "Launch from carrier".
To equip an aircraft for catapulting in Plane Maker, you have to observe some special rules in the design of the Landing Gear: For catapult take-offs from a carrier, you have to have a landing gear #1 element on the centreline of the aircraft ahead of the centre-of-gravity. X-Plane applies the catapulting force on that landing gear element, assuming that it is catapultig a modern, US-American tricycle jet which is attached to the catapult sled by the nosewheel in element #1 position. Trying to catapult a tail-dragger built without a suitably positioned dummy landing gear element #1 will sling it off sideways or tail-forward!
Flying off the deck without catapult launchEdit
If you plan to fly an aircraft off the deck of a carrier without catapult launch, you cannot use the "Special Take-off" menu item to place it on the carrier as that will set it up for a catapult launch. Instead, you have to locate a map section with a carrier (carriers are always near the coast), then drag and drop the aircraft onto the carrier (at altitude 0 ft).
While carrier landings can be made with any aircraft that is capable of stopping in the length of the deck (one way or the other), standard procedure in the real world is to equip fixed-wing aircraft with arresting gear. In Plane Maker, arresting gear is added under Special Controls: Arresting gear equipped.
One special (and very helpful) aid for landing on a carrier deck is the "AoA indexer", an instrument that enables the pilot to achieve the correct angle-of-attack for a carrier landing regardless of the current aircraft weight. The correct function of this instrument depends on the figure for the stall warning entered on the Viewpoint screen. (The approach speed for carrier landings is usually somewhat lower than for runway landings.)
Note: Make sure to perform at least one carrier landing with your aircraft with the AoA indexer perfectly centered, then check the attitude of your aircraft on touch-down to see if it's correct (meaning that the main wheels touch down first but the tail is still clear of the deck). Taildragger operation might actually see the tailwheel touching down first, as for example with the Vought F4U Corsair.