Land Base Aerial Support

Introduction
The Land-Base Aerial Support (tentative name abbreviated as LBAS for now) is a system introduced in the May 2nd-3rd 2016 update along with the Spring 2016 Event, which enables seaplane, carrier-based, and land-based aircraft (but not Autogyro/Liaison Aircraft) to be launched from an air base and to assist you during the sortie.

Currently, this system is only available in E4, E5, and E7 during Spring 2016 Event.

Prerequisite
Currently, the only way to unlock the air base is to clear E3 and its prerequisites during the Spring 2016 Event.

You will receive your 1st Air-base after clearing E3 and your 2nd Air-base after clearing E4.

The 3rd air base can be unlocked by clearing E5 during the Spring 2016 Event. Though E5 is optional, players are recommended to clear E5 before proceeding to E7 for additional air-base firepower.

How To Use
First introduced in Spring 2016 Event, after clearing the Map E3, you'll be able to establish an air base from which you can launch aircraft from. You can launch carrier-based aircraft and seaplanes, as well as land-based aircraft that is exclusive to this support system.

In certain maps where land-base aerial support is available, you can activate the support and assign aircraft to the airbase as shown here:

When the land-base aerial support is active for that map, a mark will be displayed below the sortie button.

At the start of the sortie, you can designate up to two target nodes per airfield where aerial support will be performed. You can also select a single node in order to concentrate all of your aerial support there.

When you reach the node where the aerial support is requested, a land-based air battle will take phase before the carrier-based air battle, the support expedition, and the initial torpedo strikes. This allows them to weaken the enemy air fleet and their air power, allowing your fleet's air force to secure air superiority more easily.

If you have cleared Spring Event E4, you'll have an additional airfield to accommodate more aircraft, allowing you to target four nodes instead of two. Clearing Spring Event E5, will unlock the 3rd airbase fleet/squadron.

Similar to the shipgirls, the air fleet that are assigned to the air base needs to be resupplied as well.

The refueling process for aircraft is similar to the refueling the shipgirls. However, the right box resupplies bauxite instead of ammunition.

Use drag and drop to un-equip a plane from air base.

Aircraft Flight Range and Classification
Aircraft that can be assigned into an air base can be divided into the following categories:
 * Carrier-based Aircraft : Can be equipped on both air base and aircraft carriers. May be further categorized as fighter, bomber, and recon aircraft.
 * Seaplanes : Can be equipped on air base, cruisers, and battleships. Generally have lower performance compared to carrier-based aircraft.
 * Flying Boats : Can only be equipped on a flying boat tender (such as Akitsushima) or air base. Has enormous flight range.
 * Land-based Attack Aircraft : Has greater flight range than carrier-based aircraft, but cannot be equipped on shipgirls.
 * Interceptor Aircraft : Purpose-built aircraft for intercepting bombers that are stationed in the air base. Has lowest flight range.

Options
There are 5 options in the airbase menu as shown below. You can click the label to flip between these options:



Those options are, in left-to-right (for pictures above) to descending order (for description below):
 * 【出撃】 Sortie
 * Allows the player to choose nodes where you want airbase support.
 * Recommended if you requires extra firepower in a few nodes.
 * 【防空】 Air Defense
 * Protects Air Base from Enemy Raid.
 * 【退避】 Retreat
 * Prevent your planes being damaged by Enemy Air Raid. However, damage to resources stockpile might increase?
 * 【休憩】 Rest
 * Recovers morale of planes
 * (If planes are at lowest condition, after 2 - 3 runs of any map with LBAS conditions, planes will recover?)
 * 【待機】 Standby
 * Sortie your fleet without airbase support?

Choosing sortie will allow you to choose nodes you want airbase support. Choosing Air defense will skip the choosing node process but will allow interception of enemy air raids, so you should only choose Air Defense mode with AA planes equipped at the airbase. Retreat is currently unknown. Rest supposedly means you don't want airbase support at maps where you can use it and thus you'll not have an option to choose which nodes to attack.

Cost

 * Putting planes onto a land base consumes bauxite.
 * Check these links to see each plane's cost:
 * Fighter, Torpedo Bomber, Dive Bomber, Seaplane, Land-based Attack Aircraft, Interceptor Fighter, Reconnaissance
 * Note that the cost listed in these tables are the cost for equipping 1 plane, but each slot in your land base can have 4 planes (for reconnaissance planes) or 12 planes (for other planes), so you'd need to multiply the listed cost by 4 or 12 respectively to get the equip cost per slot.
 * Some planes, like Shinden Kai, Prototype Seiran, and Type 1 Land-based Attack Aircraft cost more than a hundred bauxite just by putting them into the air base.
 * Sortieing planes consumes fuel and ammo.
 * You can check the cost by comparing your fuel and ammo before and after the sortie.
 * Resupplying planes would consume fuel and bauxite.
 * Fuel consumption is equal to 3 times the number of planes lost, and ammo consumption is equal to 5 times the number of planes lost

Limitations

 * Each aircraft has their own "flight range", which indicates the combat radius of the aircraft. Aircraft that have low flight range may not be able to effectively support the map nodes that are too far away from their air base. In most cases, land-based fighters have greater combat radius than carrier-based aircraft.
 * The aerial battle phase of Land-Base Aerial Support is calculated separately from Opening Airstrike and Support Airstrike expeditions, and aerial conditions from one phase will not be carried over to subsequent phases. Securing air superiority or air supremacy during Land-Base Aerial Support phase can weaken the enemy fleet's air power, reducing the required air power to secure air superiority for your fleet.
 * The air fleet may become demoralized if your fleet does not reach the node their supports are assigned to. The Air Fleet can also be demoralized if used too often.
 * When you change an aircraft that is assigned in the land base, the aircraft that is switched out will be tagged with "配置転換中" to indicate that it is currently being relocated, and it will be unavailable to be reassigned to either a land-base or shipgirls for the duration (20 minutes ). Thus, do NOT change your aircraft too often.
 * Each airbase slot only has 12 planes and thus they are quite susceptible to enemy Anti Air especially when ships like Light Cruiser Tsu-Class present.
 * Warning: Swapping an aircraft assigned to the land base can cost you Bauxite depending on which plane you are swapping them into. There is no usage indicator to show the potential loss of Bauxite. Thus, do NOT change your aircraft too often.
 * Warning: When a land base squadron is sortied, it will cost  fuel and some ammo per squad. Again, there is no indicator that this is happening.

Enemy Raid
 

As of May 5, 2016 Update. Along with the update of increasing the Air Base Support Damage, Abyssal can now Raid your Air Base in Spring'16 E5. This is triggered randomly within the map itself, destruction of the Air Base will result in your Land Base Aerial Support not triggering in the designated location. To prevent this, you must assign a  Squadron to defend the Base. Enemy Raids will always occur twice before reaching the Boss node.



Mechanics
Outlined below is how the LBAS operates during a sortie

AA Calculations
There are 12 planes per slot in your Land Base hanger. This works the same as if you were to equip them in a 12 slot carrier equipment slot.
 * Example a Reppuu has about 60 AA rating at rank 7
 * Note that Interceptors Do not get a large AA bonus from rank the way fighters do.

Sortie Aerial Combat
When you sortie to a designated node the bombing phase is identical to that of the Carrier Aerial Combat phase.
 * AP/AS/AS+ is calculated per Bombing wave based on that squad's AA strength.
 * If your bombing attack experiences Air Denial red text will be displayed at the bottom of the screen
 * If your bombing attack experiences Air Incapability orange text will be displayed at the bottom of the screen
 * There is no text message for AP/AS/AS+
 * Depending on AP/AS/AS+ a number of enemy planes will be destroyed. (And yours as well) The numbers are the same as if it were a Carrier Aerial Combat phase. Your fleet AA is calculated in the amount of planes that are killed.
 * AP/AS/AS+ is recalculated after every bombing pass, based on the remaining enemy fighters that survived previous bombing passes.
 * Using Air Defense will add the AA of that squad to every bombing pass.

Air Defense
Setting a squad on air defense will add air protection on each node
 * The AA of the squad is added to the AA of your fleet during Aerial Combat
 * Saiun in an Air Defense Squad will act as if they were apart of your main force. Thus removing the chance of Red T.
 * Spotting aircraft will provide spotting for your main fleet and any squads that are assigned to bomb any node.

Plane Rank
The rank of your aircraft is the same as if they were equipped to a carrier.
 * Ranked 7 bombers will give the same bonus damage per slot (10%) and an extra 10% if all the slots are ranked 7 bombers
 * Ranked 7 Land based bombers bonus damage is unknown. From experimentation it seems to be greater than that of normal carrier bombers.
 * Ranked 7 Interceptors do not get an AA bonus, but instead increase their bomber killing efficiency.
 * Sortieing 1SS to E-5 and then having all your land based aircraft attack A. Then clearing the node and retreating is a quick way to increase Land based Bomber and Interceptor Ranks.
 * If too many Bombers are killed or your Air Base is killed in an Enemy Raid. You will lose ranks on those aircraft the same as if a Carrier were to lose all its planes in one of its slots.

Distance Calculations
The distance shown on the aircraft doesn't reflect their actual deployment range for some aircraft. Below is a list of exceptions or anomalies.
 * Some Fighters and Interceptors can go double their listed distance. However, they take automatic damage for doing so.  It is hypothesized that this is a 1 way trip for the fighter escort and their AA  effectiveness drops as they exceed their max range.
 * Planes that have unique names can go +1 further distance.
 * Rank also may have an effect on distance. Planes have been observed to not be able to deploy to the same node they did in the previous sortie after losing rank. Zuiuns have been observed behaving as such.
 * Range of your entire squad is determined by the plane with longest range within your squad. However, when you force those short-ranged aircraft to go further than their original range, their performance might drop.

Damage to Squads from Enemy Raid
Damage to your bases during an Enemy Raid works the same as when your ships take damage
 * Orange (50% hp or less) damage output and fighter strength reduced to 70%
 * Red (20% hp or less) damage output and fighter strength reduced to 40%
 * If a squad dies it will not show up to the designated node

Note: You can send a bombing sortie to a Air Vs Air node and physically damage the enemies. It is currently unknown if this is a bug, or if killing these enemies results in a special debuff effect.

Trivia

 * When the system was first implemented on May 3rd 2016, there was a bug that caused the bombing damage from land-base aerial support to be omitted from internal enemy HP damage calculation, which occasionally causes a supposedly sunk enemy unit to be able to act as if they were alive (able to attack/be targeted by your fleet), as shown here
 * Two days after the system's implementation, an emergency update were made to fix the performance for land-base attack aircrafts
 * The air base featured during the Spring 2016 Event is located in Johnston Atoll, while the air base in Spring 2016 Event E5 is the Henderson Field (now Honiara International Airport) located at Solomon Islands near to Buin and Rabaul.