Anti-Air Fire

Introduction

This page is to provide detail on how plane shoot down is calculated during the Fleet Air Defense phase of aerial combat.

Fleet Air Defense

Take note that anti-air in a combined fleet works slightly differently to a single fleet.

Adjusted Anti-Air

There are two adjusted anti-air values that are taken into account when calculating shoot down; the ship adjusted AA and fleet adjusted AA. The following formulas only apply to ship girls. Abyssals have their own formula.

[math]\displaystyle{ \text{Adj AA}_\text{ship} = \text{AA}_\text{ship} + \sum_{\text{All Slots}} \left( \text{Mod}_\text{equipS} \times \text{AA}_\text{equip} \right) + \left( \text{Mod}_\text{ImprS} \times \sqrt{\bigstar} \right) }[/math]

• [math]\displaystyle{ \text{AA}_\text{ship} }[/math] is the base of the ship.
• [math]\displaystyle{ \text{Mod}_\text{equipS} }[/math] is the ship anti-air equipment modifier.
  • High-Angle Mounts/Anti-Air Fire Director: [math]\displaystyle{ 4.0 }[/math]
  • Anti-Air Guns: [math]\displaystyle{ 6.0 }[/math]
  • Air RADARs: [math]\displaystyle{ 3.0 }[/math]
  • Other equipment: [math]\displaystyle{ 0 }[/math]
• [math]\displaystyle{ \text{AA}_\text{equip} }[/math] is the base of the equipment.
• [math]\displaystyle{ \text{Mod}_\text{ImprS} }[/math] is the ship anti-air equipment improvement modifier.
  • High-Angle Mounts: [math]\displaystyle{ 3.0 }[/math]
  • Air RADARs: [math]\displaystyle{ 0 }[/math]
  • Anti-Air Guns: [math]\displaystyle{ 4.0 }[/math]
• [math]\displaystyle{ \bigstar }[/math] is the level of Improvement.

[math]\displaystyle{ \text{Adj AA}_\text{fleet} = 1.54 \times \lfloor \text{Mod}_\text{formation} \times \sum_{\text{All Ships}} \left( \sum_{\text{All Slots}} \left( \text{Mod}_\text{equipF} \times \text{AA}_\text{equip} \right) + \left( \text{Mod}_\text{ImprF} \times \sqrt{\bigstar} \right) \right) \rfloor }[/math]

• [math]\displaystyle{ \text{Mod}_\text{formation} }[/math] is the formation modifier.
  • Line Ahead/Echelon/Line Abreast: [math]\displaystyle{ 1.0 }[/math]
  • Vanguard: [math]\displaystyle{ 1.1 }[/math]
  • Double Line: [math]\displaystyle{ 1.2 }[/math]
  • Diamond: [math]\displaystyle{ 1.6 }[/math]
• [math]\displaystyle{ \text{Mod}_\text{equipF} }[/math] is the fleet anti-air equipment modifier.
  • High-Angle Mounts/Anti-Air Fire Director: [math]\displaystyle{ 0.35 }[/math]
  • Anti-Air Guns/Main Guns/Secondary Guns/Seaplanes: [math]\displaystyle{ 0.2 }[/math]
  • Anti-Air RADARs: [math]\displaystyle{ 0.4 }[/math]
  • Anti-Air Shells: [math]\displaystyle{ 0.6 }[/math]
• [math]\displaystyle{ \text{AA}_\text{equip} }[/math] is the base of the equipment.
• [math]\displaystyle{ \text{Mod}_\text{ImprS} }[/math] is the fleet anti-air equipment improvement modifier.
  • High-Angle Mounts: [math]\displaystyle{ 3.0 }[/math]
  • Anti-Air RADARs: [math]\displaystyle{ 1.5 }[/math]
  • Anti-Air Guns: [math]\displaystyle{ 0 }[/math]
• [math]\displaystyle{ \bigstar }[/math] is the level of Improvement.

Fixed Shoot Down

[math]\displaystyle{ \text{Shootdown}_\text{fixed} = \frac{ \left[ \text{Mod}_\text{equipped} \times \frac{\text{AA}_\text{ship} + \text{Adj AA}_\text{fleet}}{\text{Mod}_\text{equipped}} \right] \times \text{Mod}_\text{AACI} \times \text{Mod}_\text{CF}}{10} }[/math]

• [math]\displaystyle{ \text{Mod}_\text{equipped} }[/math] is the modifier if the ship has any anti-air equipment equipped.
  • It is [math]\displaystyle{ 2 }[/math] if she is equipped with something and [math]\displaystyle{ 1 }[/math] if not.
• [math]\displaystyle{ \text{Mod}_\text{AACI} }[/math] is the anti-air cut-in modifier. See below for details.
• [math]\displaystyle{ \text{Mod}_\text{CF} }[/math] is the combined fleet modifier. It is [math]\displaystyle{ 1 }[/math] otherwise.
  • Main Fleet: [math]\displaystyle{ 0.72 }[/math]
  • Main Fleet: [math]\displaystyle{ 0.48 }[/math]

Proportional Shoot Down

[math]\displaystyle{ \text{Shootdown}_\text{proportional} = \frac{ \left[ \text{Mod}_\text{equipped} \times \frac{\text{AA}_\text{ship}}{\text{Mod}_\text{equipped}} \right] \times \text{Mod}_\text{CF}}{400} \times \text{N}_\text{planes} }[/math]

• [math]\displaystyle{ \text{Mod}_\text{equipped} }[/math] is the modifier if the ship has any anti-air equipment equipped.
  • It is [math]\displaystyle{ 2 }[/math] if she is equipped with something and [math]\displaystyle{ 1 }[/math] if not.
• [math]\displaystyle{ \text{Mod}_\text{CF} }[/math] is the combined fleet modifier. It is [math]\displaystyle{ 1 }[/math] otherwise.
  • Main Fleet: [math]\displaystyle{ 0.72 }[/math]
  • Escort Fleet: [math]\displaystyle{ 0.48 }[/math]
• [math]\displaystyle{ \text{N}_\text{planes} }[/math] is the current plane count of the targeted slot.

Abyssal Anti-Air

Abyssal anti-air is weaker than ship girl anti-air and can result in 0 shoot downs. It also takes into account adjusted ship AA and adjusted fleet AA into the fixed and proportional shoot downs.

[math]\displaystyle{ \text{Adj AA}_\text{Aship} = \left[ 2 \times \sqrt{\text{AA}_\text{Aship}} + \sum_{\text{All Slots}} \left( \text{Mod}_\text{equipS} \times \text{AA}_\text{equip} \right) \right] \times \text{Mod}_\text{protection} }[/math]

[math]\displaystyle{ \text{Adj AA}_\text{Afleet} = 2 \times \left[ \text{Mod}_\text{formation} \times \sum_{\text{All Ships}} \sum_{\text{All Slots}} \left( \text{Mod}_\text{equipF} \times \text{AA}_\text{equip} \right) \right] \times \text{Mod}_\text{protection} }[/math]

• [math]\displaystyle{ \text{AA}_\text{Aship} }[/math] is the base of the Abyssal.
• [math]\displaystyle{ \text{Mod}_\text{equipS} }[/math] is the ship anti-air equipment modifier.
  • High-Angle Mounts/Anti-Air Fire Director: [math]\displaystyle{ 4.0 }[/math] (Only applies to Twin High-Angles for Abyssals).
  • Anti-Air Guns: [math]\displaystyle{ 6.0 }[/math]
  • Air RADARs: [math]\displaystyle{ 3.0 }[/math]
  • Other equipment: [math]\displaystyle{ 0 }[/math]
• [math]\displaystyle{ \text{Mod}_\text{equipF} }[/math] is the fleet anti-air equipment modifier.
  • High-Angle Mounts/Anti-Air Fire Director: [math]\displaystyle{ 0.35 }[/math]
  • Anti-Air Guns/Main Guns/Secondary Guns/Seaplanes: [math]\displaystyle{ 0.2 }[/math]
  • Air RADARs: [math]\displaystyle{ 0.4 }[/math]
  • Anti-Air Shells: [math]\displaystyle{ 0.6 }[/math]
  • Other Abyssal AA equipment (CIC, high-angle single mount, etc): [math]\displaystyle{ 0.2 }[/math]
• [math]\displaystyle{ \text{AA}_\text{equip} }[/math] is the base of the equipment.
• [math]\displaystyle{ \text{Mod}_\text{formation} }[/math] is the formation modifier.
  • Line Ahead/Echelon/Line Abreast/Combined Fleet Cruising 2/Combined Fleet Cruising 4: [math]\displaystyle{ 1.0 }[/math]
  • Vanguard/Combined Fleet Cruising 1: [math]\displaystyle{ 1.1 }[/math]\
  • Double Line: [math]\displaystyle{ 1.2 }[/math]
  • Combined Fleet Cruising 3: [math]\displaystyle{ 1.5 }[/math]
  • Diamond: [math]\displaystyle{ 1.6 }[/math]
• [math]\displaystyle{ \text{Mod}_\text{protection} }[/math] is the shoot down resistance of the plane. Please see below for more details.

For calculating Abyssal fixed and proportional shootdown:

[math]\displaystyle{ \text{Shootdown}_\text{fixed} = \bigl\lfloor \frac{\text{Adj AA}_\text{ship} + \text{Adj AA}_\text{fleet}}{10.6} \bigr\rfloor }[/math]

[math]\displaystyle{ \text{Shootdown}_\text{proportional} = \lfloor \frac{\text{Adj AA}_\text{Aship}}{400} \times \text{Slot} \rfloor }[/math]

Shoot Down Resistance

Certain elite planes have a resistance to being shot down. This is expressed as a modifier that reduces ship anti-air, fleet anti-air or both.

Plane	Ship AA Modifier	Fleet AA Modifier	Notes
Type 97 Torpedo Bomber (Murata Squadron)	0.6	1.0
Tenzan Model 12 (Murata Squadron)	0.6	1.0
Type 97 Torpedo Bomber (Tomonaga Squadron)	0.6	1.0
Tenzan Model 12 (Tomonaga Squadron)	0.6	1.0
Type 99 Dive Bomber (Egusa Squadron)	0.6	1.0
Suisei (Egusa Squadron)	0.6	0.7
Zero Fighter Type 62 (Fighter-bomber/Iwai Squadron)	0.6	0.7
Suisei Model 12 (634 Air Group w/ Type 3 Cluster Bombs)	0.6	1.0
Suisei Model 12 (w/ Type 31 Photoelectric Fuze Bombs)	0.6	1.0
Zuiun (634 Air Group)	0.6	1.0
Zuiun Model 12	0.6	1.0
Zuiun Model 12 (634 Air Group)	0.6	1.0
Zuiun (634 Air Group/Skilled)	0.6	0.7
Zuiun Kai Ni (634 Air Group)	0.5	0.7
Zuiun Kai Ni (634 Air Group/Skilled)	??	??
Jet Keiun Kai	0.5	0.7
Kikka Kai	0.5	0.5
Type 1 Land Attacker (Nonaka Squadron)	0.6	1.0

Anti-Air Cut-In

Johnston is performing the Fletcher-class exclusive API 35 AACI

When equipped with certain equipment setups, ships will be able to perform special anti-air cut-ins that will boost the shoot down values. With AACI and enough anti-air backing it, it is possible to completely wipe out incoming bombers resulting in no damage to the fleet. This would also mean disabling enemy carrier attacks during day combat due to having 0 planes.

AACI Types

Unless otherwise specified, any equipment that shares the same icon can be substituted.

API	Type	Fixed Shootdown	AACI Modifier	Trigger %	User	Notes
N/A	-	+1	1.0	-	Ship girls only.	Triggers by default to give the minimum 1 shoot down.
1		+8	1.7	65%	Akizuki-class	Any HA mount will work.
2		+7	1.7	58%	Akizuki-class	Any HA mount will work.
3		+5	1.6	50%	Akizuki-class	Any HA mount will work.
4		+7	1.5	52%	Battleships
5		+5	1.5	55%	All	Both HA guns must be a high-angle gun with built in AA fire directors.
6		+5	1.45	40%	Battleships
7		+4	1.35	45%	All
8		+5	1.5	50%	All	The HA gun must be a high-angle gun with built in AA fire directors.
9		+3	1.3	40%	All
10		+9	1.65	60%	Maya Kai Ni	The machine gun must be a special machine gun.
11		+7	1.5	55%	Maya Kai Ni	The machine gun must be a special machine gun.
12		+4	1.25	45%	All	One of the machine guns must be a special machine gun.
13	Unused
14		+5	1.45	??	Isuzu Kai Ni
15		+4	1.3	58%?	Isuzu Kai Ni
16		+5	1.4	??	Kasumi Kai Ni B
17		+3	1.25	??	Kasumi Kai Ni B
18		+3	1.2	??	Satsuki Kai Ni	The machine gun must be a special machine gun.
19		+6	1.45	??	Kinu Kai Ni	The machine gun must be a special machine gun.
20		+4	1.25	??	Kinu Kai Ni	The machine gun must be a special machine gun. The HA gun must not be a high-angle gun with built in AA fire directors.
21		+6	1.45	??	Yura Kai Ni
22		+3	1.2	??	Fumizuki Kai Ni	The machine gun must be a special machine gun.
23		+2	1.05	??	UIT-25 and I-504	The machine gun must not be a special machine gun.
24		+4	1.25	??	Tatsuta Kai Ni	The machine gun must not be a special machine gun.
25		+8	1.55	??	Ise-class Kai	The machine gun must be a 12cm 30 Tube Rocket Launcher Kai 2.
26		+7	1.4	??	Musashi Kai Ni	The HA gun must be a 10cm Twin High-angle Gun Mount Kai + Additional Machine Guns.
27	Unused
28		+5	1.4	??	Ise-class Kai/Kai Ni and Musashi Kai/Kai Ni	The machine gun must be a 12cm 30 Tube Rocket Launcher Kai 2.
29		+6	1.55	??	Hamakaze B Kai and Isokaze B Kai	Using high-angle guns with built in AA fire directors will have a high chance of triggering API 5 and 8.
30		+4	1.3	??	Tenryuu Kai Ni
31		+3	1.2	??	Tenryuu Kai Ni
32		+4	1.2	??	Royal Navy ships and Kongou-class Kai Ni	Only applies to combinations of 16inch Mk.I Triple Gun Mount Kai + FCR Type 284 OR 20 Tube 7 Inch UP Rocket Launcher and QF 2-pounder Octuple "Pom Pom" Naval Gun Mount.
33		+4	1.35	??	Gotland Kai
34		+8	1.6	~65%	Fletcher-class	Both HA guns must be 5inch Naval Gun Mk.30 Kai + GFCS Mk.37s.
35		+7	1.55	~63%	Fletcher-class	One HA gun must be 5inch Naval Gun Mk.30 Kai + GFCS Mk.37 and the other must be 5inch Naval Gun Mk.30 Kai.
36		+7	1.55	~50%	Fletcher-class	The HA guns must be 5inch Naval Gun Mk.30 Kai and the radar must be GFCS Mk.37
37		+5	1.45	~47%	Fletcher-class	Both HA guns must be 5inch Naval Gun Mk.30 Kai.

Important Notes

• Except API 1/2, only radars with an stat can trigger AACI.
• If a ship fulfills multiple AACI requirements, the lowest API number will be triggered.
  • Only a single roll is done to determine if AACI triggers.
  • This means that an AACI with lower priority but higher trigger chance can activate when a higher priority AACI fails the roll.
  • The exceptions where a ship can possibly trigger either AACI are:
    • 7 and 8
    • 19 and 20; and 8 and 20 for Kinu
    • 5 and 29 for Isokaze and Hamakaze
  • The exception to this is the Fletcher-class AACI where the game will make multiple rolls to check each AACI in ascending order.
    • They are also able to trigger 5 and 8 in addition to their unique AACI.
    • There are actually two different sets of AACI depending on if you have access to the 5"+GFCS or not. The trigger order for both sets are:
      • 5"GFCS: 34 > 35 > 5 > 8
      • 5" Kai: 37 > 36 > 5 > 8
    • The Fletcher-class AACI the most reliable AACI in the game.
• If multiple ships manage to activate AACI, the highest API number will be triggered.
  • This means you need to be careful that the powerful AACI in your fleet are not being overridden by worse AACI.
• AACI will not change the determined air control state. It only affects the bombers in the airstrike phase.

AACI Equipment Setups

Below are recommended equipment setups for anti-air cut-ins. If an AACI type is not listed, it means that it is subpar and not worth considering. The order of the equipment is for illustrative purposes only. It does not matter what order the equipment are in.

Battleships
Equipment Setup	AACI Type	Notes
	26	This is a useful setup only when Musashi is in the main fleet of a combined fleet. It also requires a reinforcement expansion so she can fit the 10cm Twin High-angle Gun Mount Kai + Additional Machine Guns in it. It slightly interferes with her daytime spotting setup but it gives a decent AACI if routing requirements are tight.
	28	This one works for Musashi, Ise and Hyuuga when you have no other AACI in the fleet. It also requires that they have a reinforcement expansion to fit the 12cm 30 Tube Rocket Launcher Kai 2 or you will be compromising their combat ability.
Heavy Cruisers
Equipment Setup	AACI Type	Notes
	10	To get the most out of this, Maya should have a reinforcement expansion so she can free up her slots for recons to maintain daytime spotting or more high angle secondary guns to night time DA.
Light Cruisers
Equipment Setup	AACI Type	Notes
	21	Ideally, the High-Angle gun should be a 8cm Twin High-angle Mount + Additional Machine Guns in Yura's reinforcement expansion. This leaves the rest of her slots free so she can still perform opening torpedoes, have a recon and gun for daytime spotting or carry seaplane fighters for air support.
Destroyers
Equipment Setup	AACI Type	Notes
	1	Even though any High-Angle mount works for triggering this AACI, you'll want the 10cm Twin High-angle Mount + Anti-Aircraft Fire Director that come with the Akizuki-class ships. It has a high fleet anti-air stat and can be upgraded for more.
	5	Generally, this isn't a very good AACI to use if you have the option of using API 1. But, it can work in a pinch if you need a more combat capable destroyer to carry the AACI role.
	29	You'll only want to use the 10cm Twin High-angle Mount to activate this AACI since it has the highest fleet AA of the guns that won't trigger API 5 instead.
/	34, 35, 36, 37	The best setup for the Fletcher-class is to have two 5inch Naval Gun Mk.30 Kai + GFCS Mk.37 and a GFCS Mk.37. This allows them to roll for all of their available AACI. Failing that, two 5inch Naval Gun Mk.30 Kai with a GFCS Mk.37 will suffice.