Air combat is one of the new features introduced in Xenonauts. Unlike in prior games where Air combat had little interaction from the player, now the player directly controls their Aircraft in-game.
The objective is to shoot down the enemy UFO's, while avoiding being shot down yourself. You control your Interceptors via a Bird's-eye view. There are several principles that are a good guide to understanding several concepts.
- Squadrons: There is strength in numbers, and you can launch up to three aircraft at once as a squadron. A lone interceptor may have a difficult time, particularly in later stages of the game, so you should be using squadrons of two or three until you are experienced with Air Combat.
- Pause: You can pause the Battle at any time by pressing Spacebar. This will allow you to issue orders or precisely time evasive rolls or launch missiles. When the Battle is unpaused, it will take place in Real Time.
- Fuel: Fuel is the primary resource of air combat. It is burned continuously by your aircraft during combat, and can be burned even faster by using special abilities such as Afterburner or the Evasive Roll. Fuel levels are imported from the Geoscape and the aircraft have to disengage from combat when they reach the minimum level of fuel required to return to base. This means that if you engage enemies near your base you'll have plenty of fuel to burn, and if you engage them a long way from base you'll be flying on fumes.
- Evade: The F-17 jets are capable of evasive rolls on a cooldown. These have a fuel cost but essentially act as a strafe command, allowing F-17s to dodge incoming fire. If used correctly it will substantially reduce the amount of damage taken by the interceptor. The MiG-32 is not able to Roll and is therefore much more vulnerable in combat.
- Missile Lock: In order to fire a missile, it must both be in range and have a missile lock acquired. Missile lock is signalled by the number in (brackets) after the weapon name. This starts counting down as soon as the target is in the 90 degree field of fire in front of the interceptor, and once it reaches zero the missile will be ready to fire.
There are many different kinds of Air weapons the player can unlock, however they all fall under one of three different classes.
- Cannons - Cannons are rapid-fire weapons that are only able to fire when there is an enemy in their fire arc, which is shown on the combat map. Cannons have a set % chance of hitting the target, so are extremely useful for destroying agile alien craft that are difficult to destroy with missiles. However, they generally have low armor penetration so are of limited use against heavily armored capital ships.
- Light Missiles - Light missiles are general-purpose missiles that can be used to engage almost all types of alien craft, as they are fast and can turn relatively quickly (although some UFOs can still Roll to evade them). However, they require missile lock before they can be fired. Light missiles are set to autofire by default.
- Heavy Missiles/Torpedoes - Heavy missiles/torpedoes are extremely powerful missiles designed to take out heavily-armored alien ships such as capital ships. They are slow and have a poor turning circle, so it is difficult to score a hit on anything but the toughest UFOs with these missiles. However, they will cause extensive damage to almost anything they hit.