Carrier Air Operations
Carrier air operations are the various procedures and techniques that make up landing on a moving ship, called an aircraft carrier: both STOL / STOVL (such as the Harrier and F-35B's) and fixed wing (F-14, F/A-18) can land on a carrier. Because of the relatively small size of aircraft carriers there are a number of rules and procedures that you should follow when on or around an aircraft carrier.
Carrier Basics
Before we dive headfirst into the procedures and rules associated with carrier air operations, we will first go over the various basics that come into play when operating on a carrier. These include items such as how does a carrier work, what does a carrier look like, and what sort of key features should you pay attention to when you cannot make out left from right when operating on a busy carrier.
Carrier Features
Because of the limited length of an aircraft carrier some special equipment is used for launching (departure, taking off) and recovering (landing) aircraft. Whereas normally a runway would net you somewhere in the ballpark of 6000 - 12000 feet of usable space, having a total length of 1100 feet is already quite spacious for an aircraft carrier. There are various types of key equipment used on a carrier:
- 1. Arresting gear
- Used to slow down / landing aircraft (recoveries)
- 2. Catapults
- Used to speed up / launch aircraft
- 3. Launch ramp
- Used to launch aircraft
- 4. IFLOLS
- Used to guide aircraft into landing (recoveries)
Ski ramps (STOBAR)
Most modern aircraft tend to be quite heavy (due to radar / sensor electronics, as well as heavy jet engines) and as such they cannot simply run off the edge of the ship at full speed to get into the air (though this was common practice for the lighter World War 2 aircraft). Instead, you could use a ramp and a high power aircraft (with very little weight).
The procedure of using a ramp to launch aircraft is called STOBAR ( Short Take-Off But Arrested Recovery ) and is a simple (cost effective) manner of launching aircraft from a carrier. For this you only need a ramp (angled bit of deck) and you will need a high power to weight ratio (i.e. lot of power, little weight) on your aircraft to launch aircraft off of the carrier.
Launching via STOBAR is done by lining the aircraft up to go off the ramp, go full thrust and launch by running off of it. Removable wheel chocks are used to hold the aircraft in place whilst you run up to full power (in the designated spots): the JBD (Jet Blast Deflector, a big piece of metal behind the plane that can be raised) is used to prevent the exhaust from the airplane preparing to take-off from blowing away other aircraft lined up behind it.
Jets take a few seconds to spool up to full power (i.e. no full thrust from the get go), so the use of these chocks is pretty vital. On some (Russian) aircraft a thrust override (carrier takeoff) switch can be set to provide even more engine power, to be used when an aircraft is heavily loaded or in bad weather conditions.
The drawbacks of using STOBAR is that you get to bring less overall weight, so less weapons and fuel to maintain the amount of power versus weight (also called the thrust vs. weight) ratio to be able to safely launch (although you will typically top up on fuel after launching from any carrier). Also, because the ramp takes up valuable space on the carrier (you can't park aircraft on the ramp), you can typically bring less planes aboard and you will not be able to launch as many planes from a STOBAR carrier (as they all have to use the same ramp to launch).
Catapults (CATOBAR)
Rather than implement the STOBAR ramp system, the United States (whom pioneered the system) and most NATO countries instead use the CATOBAR (Catapult Assisted Take-Off But Arrested Recovery system. The aircraft catapult is a launcher to which an aircraft is hooked up, which is then launched using external power from the carrier (either steam or electromagnetic power).
Up to the Cold War most aircraft used a length of reinforced rope (called a bridle) to attach to the catapult shuttle, but in all aircraft after the Cold War the shuttle instead connects to the nose gear of the aircraft via the launch bar. The pilot can selectively lower the launch bar with a switch in the cockpit to hook up to the catapult (shuttle). This shuttle also holds back the aircraft, so that the engines can be run up to full (afterburning) mode before launching. The catapult is then set to the appropriate amount of power and the aircraft can be subsequently launched.
Although more expensive (maintenance costs) to operate than the comparative ramp system, the catapult system allows you more flexibility in operating it: you can increase the amount of power on the catapult for heavier aircraft (more fuel/ordinance), as well as being able to hookup and launch multiple aircraft in quick succession by using multiple catapults.
Arresting gear
To allow aircraft to land in a much smaller space, a number of wires (typically 4 or 5) are strung across the landing deck. The aircraft catches one of these arresting wires with the use of the hook built into the airframe, after which the aircraft slows down rapidly (though quite harshly). Obviously aircraft such as helicopters and STOL/STOVL (such as the Harrier or F-35) do not need these arresting wires, as they can simply land (semi) vertically.
Because of the limited length of the landing area and the harsh landing, the aircraft used for landing on a carrier (carrier aircraft) also have very robust landing gear to withstand the high rate of descend. In a way, landing on an aircraft carrier is more controlled crashing than actual landing.
To allow aircraft carriers to launch and recover aircraft at the same time, the landing deck often has an offset: this means the landing deck is at an angle compared to the rest of the ship (typically at 9 degrees). Typically you will visually adjust for this offset (respective of the carrier course) in your landing procedure, but during nighttime or bad visibility you will be given a different heading to adjust for this offset automatically.
IFLOLS
The IFLOLS (Improved Fresnel Optical Landing System) is a system used on carriers to guide aircraft into the correct landing approach ('line-up'). Aside from extreme weather conditions or nighttime (both leading to limited visibility) landings, you will use this system to correctly line yourself up so that you may make a successful landing first time round.
The LSO (Landing Signal Officer) are in charge of operating these lights and will guide you on landing the aircraft, as well as grading the landing attempt afterwards. Please see the appropriate chapter for further information on LSO Grading: you can use the foldout button below to show the IFLOLS names for the lights.
| [Expand] | IFLOLS: Carrier Landing Lights | |
|---|
ACLS / ICLS
Carrier Deck Layout
Let's first familiarize ourselves with the overall carrier deck layout (topology). Unlike an airfield, where there is space aplenty, the carrier is quite cramped and often busy with other aircraft, so knowing where you are going (and not hindering others) is vital.
All (modern) aircraft carriers more or less have the same layout: the figure here shows the diagram of the USS Nimitz class carriers, but we could still apply the location names to all other carriers (including carriers such as the Russian Admiral Kuznetsov).
Objects such as parked aircraft or munition carts can be placed on the aircraft deck (by the mission developer): even if they are not moving ('static') they can till be collideable. So ensure your path and catapult are clear before moving, before finding out on take-off that there is an aircraft parked on the catapult.
The most critical locations on an aircraft carrier are the catapults or ramp (marked in green and numbered), and the landing deck (between the red stripes, with yellow centerline). These are for respectively launching aircraft (taking off) and recovering aircraft (landing), so like a runway, do not block them. Typical recovery or departure intervals are approximately 20 to 30 seconds, so try to cross them quick if you have to and be wary of other aircraft.
| [Expand] | Carrier Topology List | |
|---|
Knowing these areas by name is certainly not required, but know to keep the landing deck clear!
Carrier Cases
During carrier operations we use 1 of 3 possible cases, with cases each having different approaches and procedures: this is to adjust to the weather and visibility conditions. The carrier will normally dictate which case is currently in use, but mainly it is dependant on the minimum visibility ('horizontal sightlines') and ceiling ('vertical visibility') according to the table below:
| Case | Conditions | Ceiling | Visibility |
|---|---|---|---|
| 1 | No instrument conditions during daytime departures/recoveries | > 3000 ft (910 m) | > 5 nm (9.3 km) |
| 2 | (Light) Instrument conditions during daytime departures/recoveries | > 1000 ft (300 m) | > 5 nm (9.3 km) |
| 3 | Severe instrument conditions during daytime and nighttime recoveries | < 1000 ft (300 m) | < 5 nm (9.3 km) |
Please note that recovering during night time automatically defers you to a case 3 landing, regardless of actual weather and visibility conditions.
Altitudes, ranges and distances
The Air Traffic Controller in charge of the flight procedures around the carrier is called the 'Marshall', and he gets to boss you around for not flying perfectly perpendicular to his nice pattern / approach. He will tell you what case the carrier is currently operating in, gives you permission to transition to a given holding stack (altitude) or move closer to the carrier (zone).
Most notably the Marshall should tell you the BRC, or Base Recovery Course. This the current course that the carrier is moving in, and should be the course that you adhere to for landing your aircraft on the carrier deck: please note that the actual carrier landing deck is offset by 9 degrees from the BRC. During Case 3 conditions you will instead be told the FB, or Final Bearing which is the BRC adjusted with the 9 degree offset (FB = BRC - 9).
Below are the altitude blocks and zone distances associated with carrier operations:
| [Expand] Carrier Altitudes and Zoning |
|---|
Distances given in DME (Distance Measuring Equipment) are thus identical to distance from the carrier: this distance can be obtained by using the TACAN signal of the carrier or similar equipment (ICLS).
Carrier TakeOff
Carrier Landing
For this chapter we have outline the various carrier cases landing procedures and approaches: for ease of use these are split into the traffic pattern and landing pattern. The traffic pattern is used for approaching to the carrier and holding the in the traffic pattern / stack until you it is your time to land on the carrier (which usually involves waiting for other pilots to land first). The landing pattern goes about explaining the actual steps for the landing approach. Thanks to Kola360 we have also been able to provide you with the relevant communications guide for these cases.
We would like to give a massive 'Thank you' to Jabbers, Kola360 and Redkite for their contributions to making these chapters.
Case 1 Landing
Case 1 Traffic Pattern
Case 1 Landing Pattern
IFLOLS
The Case 1 landing in good visibility conditions is (and probably should be) the first type of landing you learn for carrier recovery. It follows these 3 stages:
- 1. Enter traffic pattern
- For case 1 you will contact the relevant air controllers (see communications list), which will grant your permission to enter the airspace and direct you to a holding pattern / altitude (a circle of approx. 5 nm at 1000 feet intervals, starting at 2000 feet).
- 2. Fly landing pattern
- When you are cleared by the Marshall for landing, you will use the landing pattern to get to the carrier (on final, or 'in the groove')
- 3. Line up with IFLOLS
- The final stage of Case 1 is the line-up with the IFLOLS on final approach, or 'in the groove'
Instructions for Case 1 communications and approach pattern are in the table below. For this communications example our pilot has (side) number '118' and we have a number of radio frequencies (called 'buttons'): the pilot/side number and radio frequencies will most likely be different in your scenario.
| [Expand] Case 1 Communication / Landing Pattern |
|---|
Once you have successfully reached step 7 in the communications example above you should now go into the Case 1 Landing Pattern, as follows in the table below:
| [Expand] Case 1 Landing Pattern |
|---|
Once you are on final approach / in the groove (K), you should now switch to the use of the IFLOLS system. This last phase should last around 15 - 17 seconds: any shorter and you may not be able to line up correctly, any longer and the LSO / Marshall will wave you off for being in the pattern for too long.
| [Expand] IFLOLS |
|---|
The IFLOLS landing phase will typically be accompanied by call-outs from the LSO, which can be found in the next chapter.
LSO (Landing Signal Officer)
In here you will find the various relevant callouts the Landing Signal Officer (LSO) can make during landing. Please refer to the relevant Case 1, 2, 3 landings to find specifics as to the callouts in those situations: for example during Case 1 communications are kept to a minimum (unless there are safety concerns).
Carrier Landing LSO Callouts
| [Expand] LSO Callouts |
|---|
As to the pilot 3/4 mile ball call, it used the following format:
Modex / Aircraft Type / Meatball / Fuelstate / Auto* [1]
- Modex
- Side number of aircraft
- Aircraft type
- Tomcat, Hornet, Harrier
- Meatball (IFLOLS)
- If you can visually acquire (see) the meatball, say 'ball'.
- If you cannot see the meatball, say 'clara' and the LSO will talk you in during your landing
- Fuelstate
- The fuel remaining in thoudands of pounds: 5100 pounds -> 5.1, 3500 pounds -> 3.5
- Auto
- Only say this if you are using autothrottles
So for a Hornet with 3400 pounds of fuel, with sidenumber 102, using autothrottles, of which the pilot can see the meatball, the ball call would be:
102 Hornet Ball 3.4 auto
And equally for a Tomacat with 4100 pounds of fuel, side number 118, of which the pilot cannot see the meatball:
118 Tomcat Clara 4.1
LSO Grading
After you have made a landing attempt you can expect an evaluation and grade for your landing: these are written in the LSO shorthand. On-board a carrier these are typically posted on a board, with on-going scoring: aside from bragging rights, scoring is kept to visualise performance and re-educate pilots doing poorly.
| [Expand] Overall Grade |
|---|
Aside from the overall grading board, there will also be a board or score sheet which has the development of each landing noted in the symbology. We can split this apart in the general symbology and the overall symbology, as per the LSO Natops Manual. The table below list the most frequently used entries:
| [Expand] LSO General Symbology |
|---|
Below are the additional (remaining) entries from the LSO Jargon table: these are not frequently used, unlike the ones in the general table.
| [Expand] LSO Grading Jargon |
|---|
Case 2 Landing
Case 2 recoveries (landings) are in practice a weird (Frankenstein) mix of both Case 1 and Case 3 landings, so we advise you familiarise yourself with these cases first and then come back to the Case 2 recoveries.
In essence the Case 2 recoveries are flown by entering the Case 3 Stack pattern and pushing to the boat (aircraft carrier) as normal, but once you get within visual range of the carrier you instead transition to the Case 1 Landing Pattern.
Case 3 Landing
Case 3 Landing Pattern
| [Expand] Case 3 Communication |
|---|
| [Expand] Case 3 Landing Pattern |
|---|
References
US Navy Carrier Case 1/2/3 PDF File
Aircraft Carrier Communications, two hours worth of carrier radio chatter
