Alien Ship Combat (Apocalypse)

Buildings

Note: do not move agents from a landed craft ever... to the building when in the Alien Dimension when in the select squad screen. Keep them in the craft, click the craft to highlight all agents or click each agent individually, then click the "search" or "raid" buttons when ready.

X-Com craft do not need to be at the base all the time. Spread your craft around the city to buildings which have multiple launch tubes when using multiple airbourne craft. Don't crowd many craft into one-tube-buildings! Choose buildings which, when collapsing, would not damage craft in the process of taking off.
Craft will launch from multiple tubes even if the yellow craft icon doesn't appear over an actual tube.
After combat, return to base to repair, refuel and rearm and afterwards, send them to the buildings again. Troop transports and any damaged vehicles need to stay at the base.
If your craft has sustained damage, depending on the attitude (note: not altitude), it will immediately try to return to base. It will fly a straight line and does not avoid any threats. To stop this action, changing the attitude to a more aggressive setting will regain control (from forced "Returning to Base" messages) of the damaged craft. You can then choose a direction to fly away from the air-battle or to force that craft back into the fight. The more 'mild' the attitude, the earlier that craft will break-off when sustaining damage.

Vehicles

Hoverbikes

Hoverbikes are very weak. Use them as a swarm. They are very good at evasion, even better when upgraded with the best engines allowing higher speed and the full (10) acceleration.
The 'heaviest' weapon available is the Lineage Plasma Cannon but regarding the low constitution of this vehicle, this may become expensive.

Hovercars

Hovercars can mount two weapons and have room for one Small Shield. They should be upgraded with the best engine since they are underpowered from the factory.
Firepower can be double of the Hoverbike and can be worthwhile since it will survive longer in battle, more-so with a shield.

Valkyrie

Expensive but durable. Plasma cannons mounted ensures this vehicle can knock them down whilst being knocked about. Even better with three small shields.

Air Hawk

Expensive, durable, three weapon mounts. Heavy vehicle but can mount the Medium Disruptor Beam. Turns slowly which can be a liability. Will last long in battle when using small shields but can be overwhelmed.

Airborne Tactics

A mixed force of hovercars and hoverbikes works quite well in the beginnings of the game.
Fast (evasive agression) hoverbikes can attract fire from enemy craft whilst less agile hovercars can destroy from a distance when set to cautious agression.
Slow craft (purposely given weak engines) with missiles will launch them at the target directly if flying towards the enemy from long distance. This will allow the missile to flt straight at the target instead of turning to try to hit.
Giving waypoints to vehicles en-route to battle may help in tactics.
- Switch to overhead cityscape view. Give a vehicle a target (building or craft). Click the "Go to Location" button. Hold down CRTL button then click on the cityscape somewhere to set a waypoint. Close the pop up window. The craft will fly the waypoints first then resume to the target.

Height

The highest setting enables unobstructed flight paths.
The lowest setting is just above road level. Larger craft have slightly weaker top armor which may be an issue when shields are not available.
Using the highest setting allows room for missile flight but forces your craft to shoot downwards at a hostile (at a lower height). If your weapons miss, they may impact a building.
Using a lower (but not lowest) height setting can make air combat more difficult due to building proximity and possible collapse affecting your craft, but it allows the possibility of shooting up at a target. If the shots miss, they fly off into the sky and not into a building.
Over unowned land or outside citywalls, shoot down is best since it allows maximum 3D movement.
Inside the city, lower height setting should be used since the enemy may miss and hit a building (to your Relations advantage). Enemy missiles will be flying downwards also. If they miss they often impact the ground which reduces the overall threat.

Attitude

Attitude (evasive to angry) influences the disengagement from battle according to damage sustained to that craft.
An agressive combat setting will make your air craft get very close to the target. This will affect enemy missiles since they have to turn immediately, but limits your available space for evasive moves. If you have many craft swarming an enemy, the hostile cannot move easily. Craft will often fire even if there is a friendly in the way.
A Cautious attitude enables weapon use at distance (typically 10 city cells distance to target). Weapons may miss if the target is nimble. Overshoot into buildings may pose a problem.
Evasive attitude will prevent your craft from using weapons. This is best when flying long distance to a target so that your craft do not fire on hostile road vehicles.
Changing combat attitude as an air battle progresses may prevent UFOs from being destroyed outright. Switch to Evasive just before the UFO is destroyed. Missiles in flight will be cause for guesswork!

Don't forget to use the Pause button.

Other

This point cannot be stressed enough: make sure that you remove your agents from their vehicles/aircraft before sending them to engage Alien ships. If your craft is destroyed, the agent piloting it will perish too along with his/her equipment. Isn't that irritating?