As with departures, the type of recovery is based on the meteorological conditions and are referred to as case I, case II, or case III.
Aircraft awaiting recovery hold in the "port holding pattern", a left-hand circle tangent to the ship's course with the ship in the 3-o'clock position, and a maximum diameter of 5 nmi. Aircraft typically hold in close formations of two or more and are stacked at various altitudes based on their type/squadron. Minimum holding altitude is 2,000 feet, with a minimum of 1,000 feet vertical separation between holding altitudes. Flights arrange themselves to establish proper separation for landing. As the launching aircraft (from the subsequent event) clear the flight deck and landing area becomes clear, the lowest aircraft in holding descend and depart the stack in final preparation for landing. Higher aircraft descend in the stack to altitudes vacated by lower holding aircraft. The final descent from the bottom of the stack is planned so as to arrive at the "Initial" which is 3 miles astern the ship at 800 feet, paralleling the ship's course. The aircraft are then flown over the ship and "break" into the landing pattern, ideally establishing at 50-60 second interval on the aircraft in front of them.
If there are too many (more than 6) aircraft in the landing pattern when a flight arrives at the ship, the flight leader initiates a "spin", climbing up slightly and executing a tight 360° turn within 3 nmi of the ship.
The break is a level 180° turn made at 800 feet, descending to 600 feet when established downwind. Landing gear/flaps are lowered, and landing checks are completed. When abeam (directly aligned with) the landing area on downwind, the aircraft is 180° from the ship's course and approximately 1.5 miles from the ship, a position known as "the 180" (because of the angled flight deck, there is actually closer to 190° of turn required at this point). The pilot begins his turn to final while simultaneously beginning a gentle descent. At "the 90" the aircraft is at 450 feet, about 1.2 nmi from the ship, with 90° of turn to go. The final checkpoint for the pilot is crossing the ship's wake, at which time the aircraft should be approaching final landing heading and at ~350 feet. At this point, the pilot acquires the Optical Landing System (OLS), which is used for the terminal portion of the landing. During this time, the pilot's full attention is devoted to maintaining proper glideslope, lineup, and "angle of attack" until touchdown.
Line up on landing area centerline is critical because it is only 120 feet wide, and aircraft are often parked within a few feet either side. This is accomplished visually during Case I using the painted "ladder lines" on the sides of the landing area and the centerline/drop line (see graphic).
Maintaining radio silence, or "zip lip", during Case I launches and recoveries is the norm, breaking radio silence only for safety-of-flight issues.
This approach is utilized when weather conditions are such that the flight may encounter instrument conditions during the descent, but visual conditions of at least 1,000 feet ceiling and 5 miles visibility exist at the ship. Positive radar control is utilized until the pilot is inside 10 nmi and reports the ship in sight.
Flight leaders follow Case III approach procedures outside of 10 nmi. When within 10 nmi with the ship in sight, flights are shifted to tower control and proceed as in Case I.
This approach is utilized whenever existing weather at the ship is below Case II minimums and during all night flight operations. Case III recoveries are made with single aircraft, with no formations except in an emergency situation).
All aircraft are assigned holding at a marshal fix, typically about 180° from the ship's Base Recovery Course (BRC), at a unique distance and altitude. The holding pattern is a left-hand, 6-minute racetrack pattern. Each pilot adjusts his holding pattern to depart marshal precisely at the assigned time. Aircraft departing marshal will normally be separated by 1 minute. Adjustments may be directed by the ship's Carrier Air Traffic Control Center (CATCC), if required, to ensure proper separation. In order to maintain proper separation of aircraft, parameters must be precisely flown. Aircraft descend at 250 knots and 4,000 feet per minute until 5,000 is reached, at which point the descent is lessened to 2,000 feet per minute. Aircraft transition to a landing configuration (wheels/flaps down) at 10-nmi from the ship.
Since the landing area is angled approximately 10° from the axis of the ship, aircraft final approach heading (Final Bearing) is approximately 10° less than the ship's heading (Base Recovery Course). Aircraft on the standard approach (called the CV-1) correct from the marshal radial to the final bearing at 20 miles. As the ship moves through the water, the aircraft must make continual, minor corrections to the right to stay on the final bearing. If the ship makes course correction (which is often done in order to make the relative wind (natural wind plus ship's movement generated wind) go directly down the angle deck, or to avoid obstacles), lineup to center line must be corrected. The further the aircraft is from the ship, the larger the correction required.
Aircraft pass through the 6-mile fix at 1,200 feet altitude, 150 knots, in the landing configuration and commence slowing to final approach speed. At 3 nmi, aircraft begin a gradual (700 foot per minute or 3-4°) descent until touchdown. In order to arrive precisely in position to complete the landing visually (at 3/4 nmi behind the ship at 400 ft), a number of instrument systems/procedures are used. Once the pilot acquires visual contact with the optical landing aids, the pilot will "call the ball". Control will then be assumed by the LSO, who issues final landing clearance with a "roger ball" call. When other systems are not available, aircraft on final approach will continue their descent using distance/altitude checkpoints (e.g, 1200 ft at 3 nmi, 860 ft at 2 nmi, 460 ft at 1 nmi, 360 ft at the "ball" call). Pilots are taught to always back up their other approach systems with this basic procedure.
The Carrier Controlled Approach is analogous to ground-controlled approach using the ship's precision approach radar. Pilots are told (via voice radio) where they are in relation to glideslope and final bearing (e.g., "above glideslope, right of centerline"). The pilot then makes a correction and awaits further information from the controller.
The Instrument Carrier Landing System (ICLS) is very similar to civilian ILS systems and is used on virtually all Case III approaches. A "bullseye" is displayed for the pilot, indicating aircraft position in relation to glideslope and final bearing. The Automatic Carrier Landing System (ACLS) is similar to the ICLS, in that it displays "needles" that indicate aircraft position in relation to glideslope and final bearing. An approach utilizing this system is said to be a "Mode II" approach. Additionally, some aircraft are capable of "coupling" their autopilots to the glideslope/azimuth signals received via data link from the ship, allowing for a "hands-off" approach. If the pilot keeps the autopilot coupled until touchdown, this is referred to as a "Mode I" approach. If the pilot maintains a couple until the visual approach point (at 3/4 mile) this is referred to as a "Mode IA" approach.
The Long Range Laser Lineup System (LLS) uses eye-safe lasers, projected aft of the ship, to give pilots a visual indication of their lineup with relation to centerline. The LLS is typically used from as much as 10 nmi until the landing area can be seen at around 1 nmi.
Regardless of the case recovery or approach type, the final portion of the landing (3/4 mile to touchdown) is flown visually. Line up with the landing area is achieved by lining up painted lines on the landing area centerline with a set of lights that drops from the back of the flight deck. Proper glideslope is maintained using the Fresnel lens Optical Landing System (FLOLS), Improved Fresnel Lens Optical Landing System (IFLOLS), or Manually Operated Visual Landing Aid System (MOVLAS).
If an aircraft is pulled off the approach (if the landing area is not clear, for example) or is waved off by the LSO (for poor parameters or a fouled deck), or misses all the arresting wires ("bolters"), the pilot climbs straight ahead to 1,200 feet to the "bolter/wave-off pattern" and waits for instructions from approach control.