Modern US Navy carrier operations
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Modern United States Navy aircraft carrier operations include the command, administrative, operating and maintenance tasks involved in preparing, planning, scheduling, arming and fuelling, crewing, launching and retrieving fixed wing and rotary aircraft, and ships' small boats by the crews of an aircraft carrier for performance of combat or non-combat missions.
Modern US aircraft carrier flight operations are highly evolved, based on nearly 70 years of experience. Knowledge of, and adherence to procedures by all participants is critical.
[edit] Flight Deck Crew / Key Personnel (see gallery below)
[edit] Air Officer
Also known as the “Air Boss”, the air officer (along with his assistant the "Mini Boss") is responsible for all aspects of operations involving aircraft including the hangar deck, the flight deck, and airborne aircraft out to 5 nautical miles from the carrier. From his perch in Primary Flight Control (PriFly or the “tower”) he and his assistant (the “Mini-Boss”) maintain visual control of all aircraft operating in the carrier control zone (surface to infinity, out to 5nm) and aircraft desiring to operate within the control zone must obtain his approval prior to entry.[1]
[edit] Catapult Officer
Also known as “Shooters,” Cat Officers are Naval Aviators or Naval Flight Officers and are responsible for all aspects of catapult maintenance and operation. They ensure that there is sufficient wind (direction and speed) over the deck, and that the steam settings for the catapults will ensure that aircraft have sufficient flying speed at the end of the cat stroke. [1]
[edit] Aircraft Handling Officer
Also known as the Aircraft Handler (or just “Handler”), the AHO is responsible for arrangement of aircraft about the flight and hangar decks. His biggest challenge is avoiding a “locked deck” where there are too many miss-placed aircraft, such that no more can land prior to a rearrangement.[1]
[edit] Landing Signal Officer
The Landing Signal Officer (LSO) is a qualified, experienced pilot that is responsible for the visual control of aircraft in the terminal phase of the approach immediately prior to landing. LSOs ensure that approaching aircraft are properly configured, and monitor aircraft glidepath angle, attitude, and lineup. They communicate with landing pilots via voice radio and light signals.[2]
[edit] Arresting Gear Officer
The AGO is responsible for arresting gear operation, settings, and monitoring landing area deck status (the deck is either “clear” and ready to land aircraft or “foul” and not ready for landing). Arresting gear engines are set to apply varying resistance (weight setting) to the arresting cable based on the type of aircraft landing.
[edit] Cyclic Operations
Cyclic Operations refers to the launching and recovering of aircraft in groups or "cycles." Launching and recovering aircraft aboard aircraft carriers is best accomplished non-concurrently, and cyclic operations are the norm for US aircraft carriers. Cycles are generally about one and a half hours long, although cycles as short as an hour or as long as an hour and 45 minutes are not uncommon. The shorter the cycle, the fewer aircraft can be launched/recovered; the longer the cycle, the more critical fuel is for airborne aircraft.[3]
"Events" are typically made up of about 12-20 aircraft and are sequentially numbered throughout the 24 hour fly day. Prior to flight operations, the aircraft on the flight deck are arranged (“spotted”) so that Event 1 aircraft can easily be taxied to the catapults once they have been started and inspected. Once the Event 1 aircraft are launched (which takes generally about 15 minutes), Event 2 aircraft are readied for launch about an hour later (based on the cycle time in use). The launching of all these aircraft makes room on the flight deck to then land aircraft. Once Event 2 aircraft are launched, Event 1 aircraft are recovered, fueled, re-armed, re-spotted and readied to be used for Event 3. Event 3 aircraft are launched, followed by the recovery of Event 2 aircraft (and so on throughout the fly day). After the last recovery of the day, all of the aircraft are generally stuffed up on the bow (because the landing area back aft needs to be kept clear until the last aircraft lands). They are then be re-spotted about the flight deck for the next morning’s first launch.[4]
[edit] Departure
[edit] Pre-launch
Approximately 45 minutes before launch time, flight crews conduct walk-around inspections and man their aircraft. Approximately 30 minutes prior to launch, aircraft are started and pre-flight inspections are conducted. Approximately 15 minutes prior to launch, ready aircraft are taxied from their parked positions and spotted on or immediately behind the catapults. The ship is turned into the natural wind. As an aircraft is taxied onto the catapult, the wings are spread and a large jet blast deflector (JBD) panel rises out of the flight deck behind the engine exhaust. Prior to final catapult hook up, Final Checkers (inspectors) make final exterior checks of the aircraft and loaded weapons are armed by Ordnancemen.
[edit] Catapult Launch
Catapult hook up is accomplished by placing the aircraft launch bar, which is attached to the front of the aircraft’s nose landing gear, into the catapult shuttle (which is attached to the catapult gear under the flight deck). An additional bar, the hold-back, is connected from the rear of the nose landing gear to the carrier deck. The holdback fitting keeps the aircraft from moving forward prior to catapult firing. In final preparation for launch, a number of events happens in rapid succession and are indicated by hand/light signals:
- The catapult is put into “tension” whereby all the “slack” is taken out of the system with steam. *Simultaneously, the pilot advances the throttles to full (or “military”) power and takes his feet off the brakes. The holdback fitting (mentioned above) keeps the aircraft from moving forward.
- The pilot checks engine instruments and “wipes out” (moves) all the control surfaces.
- The pilot indicates that he is satisfied that his aircraft is ready for flight by smartly saluting the Catapult Officer. At night, he turns on the aircraft’s exterior lights to indicate he is ready.
- During this time, two or more Final Checkers are observing the exterior of the aircraft for proper flight control movement, engine response, panel security and leaks.
- Once satisfied, the Checkers give a thumbs up to the Cat Officer.
- The Cat Officer makes a final check of catapult settings, wind, etc. and gives the signal to launch.
- The catapult operator then pushes a button firing the catapult.
Once the catapult fires, the hold-back breaks free as the shuttle moves rapidly forward, dragging the aircraft by the launch bar. The aircraft accelerates from zero (relative to the carrier deck) to approximately 150 knots in about 2 seconds. There is typically wind (natural or ship motion generated) over the flight deck, giving the aircraft additional lift.[5]
[edit] Post Launch
Procedures used after launch are based on the meteorological / environmental conditions (weather and daylight).
[edit] Departure / Recovery Types
There are three types of departure and recovery operations, which are referred to as Case I, Case II, and Case III.
- Case I: When it is anticipated that flights will not encounter instrument conditions (Instrument meteorological conditions) during daytime departures/recoveries, and the ceiling and visibility around the carrier are no lower than 3,000 feet and 5 nm respectively.
- Case II: When it is anticipated that flights may encounter instrument conditions during a daytime departure/recovery, and the ceiling and visibility in the carrier control zone are no lower than 1,000 feet and 5 nm respectively. Used for an overcast condition.
- Case III: When it is anticipated that flights will encounter instrument conditions during a departure/recovery because the ceiling or visibility around the carrier are lower than 1,000 feet and 5 nm respectively; or for night time departures/recoveries.
[edit] Case I Departure
Immediately after becoming airborne, aircraft raise their landing gear and perform “clearing turns” to the right off the bow, and to the left off the waist catapults. This ~10° check turn is to increase separation of (near) simultaneously launched aircraft from the waist/bow catapults. After the clearing turn, aircraft proceed straight ahead paralleling the ship’s course at 500 feet until 7 nm. Aircraft are then cleared to climb unrestricted in visual conditions.
[edit] Case II Departure
After a clearing turn, aircraft proceed straight ahead at 500 feet paralleling ship’s course. At 7 nm, aircraft turn to intercept a 10-nm arc about the ship, maintaining visual conditions until established outbound on their assigned departure radial, at which time they are free to climb through the weather. The 500-foot restriction is lifted after 7 nm if the climb can be continued in visual conditions.
[edit] Case III Departure
A minimum launch interval of 30 seconds is used between aircraft, which climb straight ahead. At 7 nm, they turn to fly the 10-nm arc until intercepting their assigned departure radial.
[edit] Control of departing aircraft
- Primary responsibility for adherence to the departure rests with the pilot; however, advisory control is given by the ship’s Departure Control radar operators, particularly when required by weather conditions dictate.
[edit] Tank/Rendezvous
[edit] Mission
[edit] Returning to the carrier
[edit] Entering the Carrier Control Area
All aircraft within the carrier’s radar coverage (typically several hundred miles) are tracked and monitored. As aircraft get closer to the carrier, they are given more scrutiny. Once airwing aircraft have been identified, they are normally turned over to “Marshal Control” for further clearance to the “marshal pattern”.
[edit] Recovery Types
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.
[edit] CASE I
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 nm. 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.[6]
[edit] Spin
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 3nm of the ship.
[edit] Landing Pattern Entry
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 1½ 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 nm 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.[7]
[edit] Visual Lineup
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).
[edit] ZIP LIP
Maintaining radio silence, or “zip lip”, during Case I launches and recoveries is the norm, breaking radio silence only for safety-of-flight issues.
[edit] CASE II
-
- 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 nm and reports the ship in sight.
Flight leaders follow Case III approach procedures outside of 10 nm. When within 10 nm with the ship in sight, flights are shifted to tower control and proceed as in Case I.
[edit] CASE III
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 (i.e. no formations except in an emergency situation). [8]
[edit] Case III Marshal Procedures
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.
[edit] Departing Marshal
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.
[edit] Penetration/Approach
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 shallowed to 2,000 feet per minute. Aircraft transition to a landing configuration (wheels/flaps down) at 10-nm from the ship.
[edit] Correcting to the Final Bearing
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 obsticals), lineup to centerline must be corrected. The further from the ship, the larger the aircraft's correction.
[edit] Final Approach
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 3nm, 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 nm behind the ship at 400’), 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.
[edit] Non-precision or Self Contained Approach
When other systems are not available, aircraft on final approach will continue their descent using distance/altitude checkpoints (e.g. 1200’ at 3nm, 860’ at 2nm, 460’ at 1nm, 360' at the "ball" call). Pilots are taught to always back up their other approach systems with this basic procedure.
[edit] Carrier Controlled Approach
The CCA 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.
[edit] Instrument Carrier Landing System (ICLS)
The 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.
[edit] Automatic Carrier Landing System (ACLS)
The 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/azmuth 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 ¾ miles) this is referred to as a “Mode IIA” approach.
[edit] Missed Approach/Waveoff/Bolter
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”), they climb straight ahead to 1,200 feet to the “bolter/wave-off pattern” and wait for instructions from approach control.
[edit] Long Range Laser Lineup System
The 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 10nm until the landing area can be seen at around 1nm.
[edit] Optical Landing System (OLS)
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 (FLOS), Improved Fresnel Lens Optical Landing System (IFLOS)[9], or Manually Operated Visual Landing Aid System (MOVLAS).
.jpg/180px-Optical_Landing_System,_night,_aboard_USS_Dwight_D._Eisenhower_(CVN-69).jpg)
[edit] Touchdown
Immediately upon touchdown, the pilot advances the throttles to full power. Occasionally, pilots will opt to advance the throttles to maximum power (full afterburner). Ideally, the tailhook catches the target wire (or cross deck pendant), which abruptly slows the aircraft from approach speed to a full stop in about two seconds. As the aircraft’s forward motion stops, the throttles are reduced to idle, and the hook is raised on the aircraft director’s signal.[10]
[edit] Post Landing
The aircraft director then directs the aircraft to to clear the landing area in preparation for the next landing. Remaining ordnance is de-armed, wings are folded, and aircraft are taxied to parking spots and shut down. Immediately upon shutdown (or sometimes prior to that), the aircraft is refuelled, re-armed, and inspected, minor maintenance is performed, and it is often re-spot prior to the next launch cycle.
[edit] Carrier Qualifications (CQ)
CQ is performed for new pilots and periodically for experienced pilots to gain/maintain carrier landing currency. CQ requirements (the number of landings / touch and goes required) are based on the experience of the pilot and the length of time since his last arrested landing. During CQ, there are typically far fewer aircraft on the flight deck than during cyclic operations. This allows for much easier simultaneous launch and recovery of aircraft. The waist catapults (that are located in the landing area) are generally not used. Aircraft can trap and be taxied immediately to a bow catapult for launch.
[edit] Gallery
.jpg/120px-Yellowshirt(4).jpg) Yellowshirts rule the flight deck, directing the movement of all aircraft. |
 Blueshirts move, chock and chain aircraft at the direction of Yellowshirts. |
 Plane Captains (PC) wear brown and are responsible for prepairing/inspecting aircraft for flight. |
 Green shirts are generally aircraft or equipment mechanics. |
 Squadron aircraft mechanics wear green shirts. |
 Fuels personnel wear purple and are affectionately known as "grapes". |
 "Ordies" wear red. |
 Catapult Officers wear yellow with green helmets. |
 Final Checkers wear white with black checks. |
 Senior Medical Officer and Flight Surgeons wear white. |
 Landing Signal Officers, Safety personnel, and Quality Inspectors wear white. |
 Airboss and Miniboss control flight operations from Primary Flight Control. |
- Everyone associated with the flight deck has a specific job, which is indicated by the color of their flight deck jersey, float coat and helmet[11]:
- Yellow – Aircraft Directors. Direct the movement of all aircraft on the flight/hangar deck.
- Blue – Chocks and Chains. Entry level flight deck workers that work for the Yellowshirts.
- Brown – Plane Captain. Squadron personnel that prepare aircraft for flight.
- Green – Cat/Arresting Gear Operators / Aircraft Maintenance Technicians.
- Purple – Fuel (aka “grapes”). Fuel the aircraft.
- Red – Ordnancemen / Firefighter.
- White – Safety / Medical / Landing Signal Officer (LSO).
- White/black Checker – Final Checker (inspector).
[edit] External links
[Navy site: Aircraft Carriers]
[edit] References
- ^ a b c [1], CV NATOPS Manual.
- ^ [2], LSO NATOPS Manual.
- ^ http://members.tripod.com/~Motomom/CVN103
- ^ http://members.tripod.com/~Motomom/CVN103
- ^ http://science.howstuffworks.com/aircraft-carrier.htm
- ^ (1 Aug 2006) A1-F18AC-NFM-000 Naval Aviation Training and Operating Procedures Standardization (NATOPS) Manual. United States Department of the Navy, pp. 350.
- ^ (1 Aug 2006) A1-F18AC-NFM-000 Naval Aviation Training and Operating Procedures Standardization (NATOPS) Manual. United States Department of the Navy, pp. 360.
- ^ (1 Aug 2006) A1-F18AC-NFM-000 Naval Aviation Training and Operating Procedures Standardization (NATOPS) Manual. United States Department of the Navy, pp. 361.
- ^ http://www.airspacemag.com/how-things-work/meatball.html
- ^ http://science.howstuffworks.com/aircraft-carrier4.htm
- ^ http://www.navy.mil/navydata/ships/carriers/rainbow.asp
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