Air Combat (EU2012)

Air Combat Mechanic

UFO Detection

UFOs can only be engaged after they are detected by satellites and these will never detect UFOs on Abductions or Terror missions. There can be two UFOs each month, with the second UFO having a 50% or 100% chance of being generated, depending on the number of missions - see Missions (UFOs). UFOs will be detected either flying or landed - see UFO Missions for details.

Dogfight Minigame

Once the Interceptor has been launched, you will watch it chase the UFO on the world map until it catches up, at which point you will enter the dogfight minigame interface.

A Raven intercepts an Alien Supply Barge UFO. The Raven has taken about 20% damage and has Aim and Dodge modules active, indicated by the highlighting.

Key:

1. Time to loss of contact. If this reaches 0, the UFO will escape the Interceptor and will have to be re-engaged with another interceptor, if one is available.
2. The Interception craft.
3. The UFO. With practice you can learn to identify different UFO types in this interface.
4. Damage meter. When hit, this fills from the bottom. If this turns all red, the Interceptor is destroyed. You'll get a warning from the pilot at about 75% damage accumulated.
5. Abort Interception. Break off the interception and return to base. Useful if the Interception craft is getting pounded.
6. Engage UFO Tracking module, if one is available. Freezes Loss of Contact clock for five seconds, and decreases approach time for close range weapons.
7. Engage Uplink Targeting module, if one is available. Guarantees next two attacks from Interceptor hit UFO.
8. Engage Defensive Matrix module, if one is available. Allows Interceptor to dodge next two attacks from the UFO that would otherwise hit.

After Action Report

After the minigame ends, you will receive an Interception After Action Report. This will summarize the results of the interception. This is divided into three categories.

• Result: This states whether the UFO escaped pursuit, was shot down, or the interception was aborted.
• Crash: If the UFO was shot down, this will indicate that crew was seen moving at the crash site, allowing a Crash Recovery mission.
• Interceptor: This indicates what happened to your interceptor. It can receive NO damage, LIGHT damage (1-33%), HEAVY damage (33-66%), SEVERE damage(66-99%) or have been shot down altogether.

Multiple Craft Interception

Unlike the original XCOM, you cannot use multiple craft to simultaneously attack a single UFO. Instead, multiple craft serve as sequential opportunities to shoot down the UFO, with each aircraft being deployed one after another to attack the UFO.

If the 1st interceptor fails to shoot down the UFO, you can still launch more craft to try to shoot it down. However, after the 1st attempt the UFO will immediately try to escape and success in posterior attempts will depend on your craft and the UFO's speeds, their relative positions and the escape route chosen by the UFO.

Craft & Armaments Stats

Craft Stats

Craft	Range	Size	Default Weapons	Speed	Engagement Speed	HP	Armor	Armor Penetration
Interceptor	25	Small	Avalanche	1500	10	2500	5	0
Skyranger 1	25	Small	N/A	2000	10	8	0	0
Firestorm	25	Small	Avalanche	3500	20/20/15/15	6500	25	34/34/16/16
Small Scout	25	Small	UFO Plasma I	1500	20	800	0	7
Large Scout	25	Medium	UFO Plasma I	1800	22	1600	0/0/0/2	7
Abductor	25	Large	UFO Plasma II	2000	17	1800/1800/2200/2200	5/5/10/13	3
Supply Barge	25	Large	UFO Plasma II	2500	25	2000/2000/2400/2400	16/16/30/36	4
Battleship	25	Very Large	UFO Fusion	3000	40	2400/2400/2900/2900	52/52/42/52	20
Overseer	25	Medium	UFO Plasma I UFO Plasma II	3500	60	2500	64/64/45/52	25
1Although the Skyranger isn't used for air combat, the game files have values for it. Values in brackets display differences between difficulty levels (Easy/Normal/Classic/Impossible) Source: XComStrategyGame.upk game file, XGItemTree class, Enemy Within DLC version.

Armament Stats

Weapon	Range	Firing Time	Damage	Armor Pen	To Hit
Phoenix Cannon	85	1	350	11/11/6/6	95%
Avalanche	100	2	400	0	70%
Laser Cannon	85	0,75	400	25/25/25/28	85%
Plasma Cannon	100	1,25	800/800/700/700	48/48/33/33	85%
EMP Cannon	85	1,25	1200	44	100%
Fusion Lance	100	1,5	1400	44	90%
UFO Plasma I	101	1,25	300	0	75%
UFO Plasma II	101	1,25	400/400/400/500	20	75%
UFO Fusion	101	1,25	1200/1200/1250/1625	25	75%
Values in brackets display differences between difficulty levels (Easy/Normal/Classic/Impossible) Source: XComStrategyGame.upk game file, XGItemTree class, Enemy Within DLC version.

Damage Formula

Damage from the shots is calculated according to the following formulas:

0.05 * (Target Ship Armor - (Weapon AP + Firing Ship AP) = Final Mitigation (value clamped between 0 and 0.95)
Target Ship Damage = Weapon Damage * (1 - Final Mitigation)

Damage Table

Matchups proven winnable without the use of modules:

Difficulty	Easy	Normal	Classic	Impossible
Small Scout	Interceptor w/Avalanche Missiles	Interceptor w/Avalanche Missiles	Interceptor w/Avalanche Missiles	Interceptor w/Avalanche Missiles
Large Scout	Interceptor w/Avalanche Missiles	Interceptor w/Avalanche Missiles	Interceptor w/Avalanche Missiles	Interceptor w/Avalanche Missiles (misses and timeout may require 2)
Abductor	Interceptor w/Avalanche Missiles	Interceptor w/Phoenix Cannon or Interceptor w/Avalanche Missiles x2 (x1 possible)	Interceptor w/Phoenix Cannon x2 (x1 possible) or Interceptor w/Avalanche Missiles x3 (x2 possible)	Interceptor w/Laser Cannon or Interceptor w/Phoenix Cannon x2
Supply Barge	Interceptor w/Phoenix Cannon	Interceptor w/Phoenix Cannon x2 (x1 possible)	Interceptor w/Laser Cannon	Interceptor w/Laser Cannon x2
Battleship	Interceptor w/Plasma Cannon	Interceptor w/Plasma Cannon x2 (x1 possible)	Firestorm w/Laser Cannon	Firestorm w/Plasma or EMP Cannon
Overseer UFO	Firestorm w/Laser Cannon	Firestorm w/Laser Cannon x2 (x1 possible)	Firestorm w/Laser Cannon x2	Firestorm w/EMP Cannon (1 w/Plasma Cannon possible)

In Enemy Within, UFO "hit points" seem to be slightly higher in Classic, and significantly so in Impossible. The listed matchups are still possible, but for regular success against Impossible Abductors, Barges, and Battleships, a module (or luck) may be needed on top of these matchups, or another Interceptor to make up the difference. The Battleship's Fusion Lance seems more potent, as well.

Interception Tactics

Time...

Note that it take 3 days to transfer either Interceptors, or to buy a Raven, 14 (or 7 days with Advanced Construction, a late-game Foundry project) to build a Firestorm, and 24 hours to equip either kind of Interceptor with any type of weapon. Weapons removed from an Interceptor immediately become available for installation on other Interceptors, and if you dismiss a ship, its weapon will be automatically returned to your inventory. A detected UFO (landed or in-flight) will remain on the map for about 6 hours before leaving, often spawning a Battleship that is scanning to destroy your hard-earned satellite, if it is not subsequently intercepted itself (if a satellite is destroyed, that country immediately goes into full Panic, and the whole continent's panic levels also rise). You can idle on the Mission Control screen at the speed of about 1 minute a second, if it comes down to the wire. Beyond the Battleship (which can destroy satellites), letting a UFO go only affects the monthly score (which itself does not affect game play), and gets you nagged at by Central, and possibly the Council representative during the Monthly Report.

...& Money

For cost's sake: only bother putting an Interceptor on a continent with at least one satellite on it, as otherwise it cannot be called to action, as you will not be able to detect any UFOs at all over it. North America's Cover Bonus (3 satellites needed, or setting your home base there) is Air and Space: "All aircraft and aircraft weapons cost 50% less to purchase, build and maintain." Note that the basic maintenence cost is §20 for a Raven and §10 for a Firestorm: it may not be cost effective to splurge on Ravens in early months, particularly if you find yourself regularly hurting for credits. Thus, it's more efficient to have one or two well-equipped Ravens (ideally per continent) rather than the cost of maintaining (and possibly replacing) a bunch of Ravens with just Avalanche Missiles for your early months. If save-scumming, you may be able to get away with only building one or two of the latest Interceptor weapons, and slapping it on the appropriately located Interceptor (or moving just the one well-equipped Interceptor around), if there's enough time between a UFO appearance and a preceeding save state. Ravens cost §40 to buy (or §20 with the Bonus). Lastly, when constructing Firestorms: initial credit and resource cost is reduced by the number of Engineers and the aforementioned Cover Bonus, and if you have Workshop base facilities placed next to each other (Enemy Within: the Foundry and the MEC Lab included), you will get refunds of credits, alloys, and Elerium once the Firestorm is completed.

Practice

You begin all games with two Ravens at your home base equipped with Avalanche Missiles, and for the first and second month, this will be all you need, even on Impossible Difficulty: Scouts and Large Scouts will fall easily enough to one basic Raven. If the first satellite you put up (besides the one already up as your Home Base satellite) is on another continent, consider moving the second Raven to that continent's hangar the same day, so both will be ready on the same time (and do so about 4-5 days before the end of the month: if a country is covered before the end of the month, Abductions will no longer occur on it, making you potentially 'waste' the -3 Panic that placing a satellite gives).

If Panic levels and your satellite strategy allows it, focus on covering only two or three continents at first, instead of spreading out your monitor network: since detected flights will only be over those few areas, and thus covered by two or three hangars, you'll need fewer Interceptors and armaments to have coverage. Fortifying your existing network is a lot faster, safer, and cheaper than trying to expand too quickly, and risk spreading your resources too thin (while also making a move on those continental coverage bonuses).

However, when Abductor ships begin to appear...

Keeping pace with Interceptor-related research is ideal, so that even if you don't have the resulting items on hand, that with enough time between a save state and the appearance of a larger UFO, you can buy and install a stronger weapon, and/or at least buy another Raven for that continent. If you have 2 or more Interceptors on one continent, then like earlier games, you can send them both after a single UFO - just not at the same time: the Interceptor you send out before the next has to either return to base, or be destroyed, before sending the next one. Besides a missed UFO summoning a Battleship, it is a rare -- but not unheard of - occurrence that two UFOs will appear over a continent within a few days of one another, and repair times are much kinder than in the 1994 game: though if you can afford it, two interceptors a continent is still good for peace of mind and for just-in-case.

If you don't mind a bit of save-scumming when you need to send multiple Interceptors after one UFO: the runs aren't seeded, so you can reload/redo untill your ship has a good run (ie; the pilot doesn't decide to catch every plasma bolt with his face, while attempting to shoot with his ass clenching the yoke), and then save before sending out the next Interceptor.

Worst case (but still winnable) scenario is having to wait 5 hours for weapon installations to be completed (ie: Phoenix Cannons on two Ravens), sending the first Interceptor to the larger UFO (Abductor) and letting it attack until it is destroyed, then sending the second right after it, which may or may not reach the UFO, depending on the completely random path the UFO takes (even if savescumming right before, a UFO doesn't take the same path, though it will always be over the same country: UFO appearances are pre-chosen at the start of each month). A reload may place it on a more favorable flight path for your Interceptors, if you find that the UFO escapes your window of opportunity to attack it.

Naturally, researching for a Firestorm is a priority (complete both the Alien Navigation Computer and the UFO Power Source projects, then the New Fighter Craft research), and you should hoard recovered Flight Computers and Power Sources away from Grey Market sales or Council requests until you have at least 1 Firestorm for each continent. Don't forget that a Thin Man Interrogation gives a research credit to UFO Tech, and the Heavy Floater Interrogation gives another credit to Flight Research (though you easily can (and should) complete the Firestorm's research, and even get a few Firestorms out of Engineering, well before Heavy Floaters begin to show up).

You need 2 Computers and 1 Power Source per Firestorm. You may also be more likely to have a surplus of the Computers than Power Sources, so you may risk selling them, especially if you reach, say, a 10 Computer/5 Power Source quota (or however many left to put a Firestorm on each continent)-- though depending on how you're doing on Panic, you might find it more worthwhile to hold off on getting another Firestorm, and put up a Satellite Nexus instead. Note that Firestorms will always be built on your Home Base, so plus the Interceptor you should always have there, that means you can only build up to 3 at a time (or, spend up to two weeks without an Interceptor over your base's continent. Obviously, a bad idea), and that it is also another 3 days to transfer, and one more day to give it the latest weapon.

Consider that the Hyperwave Uplink also takes 14 days to build: if your game and research has gone well, you may unlock the construction of both around the same time. A possible advanced strategy is to order your Firestorms at this time. After about 5 days, begin building the Hyperwave facility. When the Firestorms are complete, move one to each continent you have active satellites on, then give them your latest armament when they arrive. Thus, their preparation and the Hyperwave facility should be complete at the same time. As the completion of the Firestorm research unlocks the EMP Cannon Research, that armament is perfect for bringing down the Overseer UFO. And as mentioned above, concerning fortifying only 2-3 continents: therefore, you will only need the 3 Firestorms that can be built without leaving your home base hangar empty. Ideally at this point, you also have some Workshop adjacency bonuses going for you, allowing you to recycle some of the credits and materials into more Firestorms, which you can move at your leisure before moving on to cover the remaining continents.

The best way to get Firestorms out to each continent without gimping yourself at home is usually to first get Plasma Cannons. Then, put two Ravens at your home base with Plasma Cannons and order two Firestorms. These two Plasma Cannon equipped Interceptors should be enough to bring down anything that comes your way while you wait for the Firestorms. Equip your first two Firestorms with whatever weapon suits your fancy (Plasma Cannons, EMP Cannons or Fusion Lances). Once they're ready, move the two Interceptors elsewhere, along with one of your new Firestorms, leaving your other one at home. Build three more Firestorms. Equip them and send them out. Provided you have enough materials, this can get you one Firestorm on each Continent with whatever weapon you so desire in 33 days:

• Day 1: First two Firestorms are ordered.
• Day 14: First two Firestorms are completed and equipping begins.
• Day 15: First two Firestorms are equipped. Hanger is cleared, next three Firestorms enter production.
• Day 18: Firestorm shipped off from home continent arrives, 2 continents covered.
• Day 29: Second batch of Firestorms are built, begin equipping.
• Day 30: Second batch of Firestorms are equipped and sent out.
• Day 33: Second Batch of Firestorms arrive at destinations, all 5 continents are covered.

Your weapons for Interceptors have to be researched and, as mentioned, it is good to at least research them in advance, so that you can buy them from Engineering (while it's a 24 hour installation, their construction is immediate) as needed (though, of course, if you can afford it, you should equip all craft with the latest available weapons ASAP). As stated, Avalanche Missiles are sufficient for Small Scouts and Large Scouts. The Phoenix Cannon is also good, though your interceptors may get battered closing the distance required. Once in range, the firing rate and accuracy tends to outweigh the risks of approaching. The Phoenix Cannon will generally add some peace of mind if you find yourself really stretched thin on Interceptors in the early parts of the game.

If you manage to capture and interrogate a Muton during their first appearance (at earliest in the 3rd month-- or if Slingshot is activated: depending on Difficulty and if in Enemy Unknown or Enemy Within, possibly as early as the 1st or 2nd month), they give a research credit to Plasma Weapons, starting with the Light Plasma Rifle, then to the long-distance, medium-rate, high-damage Plasma Cannon, often 'sequence breaking' over the short-range Laser Cannon, especially if you find yourself wanting for Plasma Weapons for most of your troops rather than Heavy Lasers for only the Heavy class (though, in Enemy Within, due to the larger reseach times required, the Laser Cannon does become the more realistic choice to proritize).

The Plasma Cannon itself is a highly effective weapon that will quickly become your go-to weapon for your Interceptors and you wouldn't be harming yourself if you equipped every plane you had (Firestorm or Raven) with Plasma Cannons and called it a day. By about this time, you may be completing the research for the Firestorm, which leads to the ability to research the EMP Cannon, a must-have for recovering max amounts of alloys, computers, and Power Sources - though at the cost of leaving more aliens alive (note that, unlike earlier XCOM games, there is never any DOA/Instant Win occasions of a UFO Crash having no survivors, or exploding outright). Lastly, the Fusion Lance, used by alien Battleships, found only after destroying a Battleship (or with the Slingshot DLC) and usable only by the Firestorm, is for making sure the UFOs die and stay dead. Not even a Battleship will be able to withstand a Fusion Lance.

Modules are of moderate use, but can be helpful for your early-game dogfights. Their construction requires the corpses of Sectoids and Floaters (for Targeting and Defense, respectively), both of which tend to disappear late-game, and Cyberdisc wrecks for Tracking.

• The Uplink Targeting module is of somewhat unpredictable use, as it guarantees the next two shots, which may or may not have hit anyways, possibly 'wasting' it. The Avalanche Missiles are the most inaccurate weapons by a large margin; while they would benefit the most from this module, you should be phasing the Missiles out at the earliest opportunity anyways. The higher accuracy of all other weapons reduces this module's usefulness fairly early into a campaign.
• The Defense Matrix module guarantees that the UFO's next two shots miss: more useful in that it's more likely that you are to be hit than you are to miss, the ideal time to use this is when the next shot the aliens take is likely to destroy your Interceptor, particularly for a Battleship's slow Fusion Lance shots.
• The UFO Tracking module extends the time your Interceptor is allowed to actually fire on a UFO before being forced to return to base. It also shortens the approach time for your short-range weapons, so you can get firing sooner and (ideally) take less damage meantime. Not too useful if you keep up with research, and get Firestorms ASAP: only the Overseer UFO and Battleships have a chance of outrunning/timing out a Firestorm, so one with a Plasma/EMP/Lance won't even need this.

Speaking of which: the Overseer UFO, like the Alien Base Assault, is a one time storyline mission, and you can (somewhat) dictate when it will appear (a few hours to a few weeks after completion of the Hyperwave Relay base facility). It is recommended to take it down with a Firestorm equipped with Plasma Cannons or better, as the UFO has both a small and a double-Plasma Cannon, and fires both of them with impunity. It does carry a large supply of Elerium (equal to a Barge), stored in two unique pairs of "Double Generators", so you may want to use EMP Cannons for the sake of this resource. You actually might not find modules to be of much use against this UFO: as said you shouldn't be using low-accuracy Avalanche Missiled against this craft, even with the Aim module, using short-range weapons is incredibly risky, so the Boost module may not be needed, and this UFO fires so rapidly, that the Dodge module will be used up in less than a second.

Also, since all continents have their hangars in a roughly centralized location, and only South America has a small "surface area" for UFOs to be engaged in, you may find it hard to attack fast UFOs like the Overseer with Ravens alone: often they'll simply make your first Raven chase them for too long, to the point that a second Raven will not have time to intercept before the UFO flies out of range entirely (Case in point: the hangar whose Interceptors will have to cover all of Russia's airspace seems to be in Poland).

The first UFO contact is always a Small Scout, and in the next month of April, you will begin to encounter Large Scouts, both of which should be easy prey for your starting 2 Ravens, even with the basic missiles (unless you're having a really unlucky day). Abductors will be the first UFOs you may have trouble with, starting in May. Supply Barges tend to appear in June, and have a significant firepower increase over the smaller UFOs. Battleships are also on equal footing with a Firestorm equipped with Plasma, EMP, or Fusion weapons, but fortunately, don't appear randomly until very late game (more often in August than July), and a speed-run (or lucky) game may not see them at all: otherwise, you can allow a UFO to escape if you feel confident about attempting to take one down, for the sake of completion and resources and experience, as it attempts to destroy your satellite network (incidentally, UFO's that are an active risk for attacking your satellite will be noted by Bradford to be having "a strange signal, like it's searching for something", and will be on the map with a scanning highlight (concentric rings)).

Perfect

The ideal endgame Interceptor situation is two Firestorms on each continent (or three if you want to feel redundant): one with a Fusion Lance, the other with either another Lance, or EMP cannons if you wish to farm UFOs (ie: more aliens to kill to level the Psi soldiers you've been buying with the money made on Grey Market sales from Computers, Sources, Elerium, and Alloys) (and the third with Plasma Cannons, because why not? Not like you can sell, say, those Phoenix Cannons you no longer need). With the strategy of sending the first Firestorm to soften the target (and abort before it gets destroyed), then sending the second to finish it off, even Battleship interceptions can become routine, without the use of modules, negating the need for the now-rare Floater and Sectoid corpses (incidentally: on Impossible Difficulty, Cyberdiscs also become rare in late-game months)(Enemy Within addendum: Sectoids will still be regularly fielded throughout a campaign as supports to Mechtoids). However, having 1 or 2 (depending on how many Firestorms you have) regular Interceptors with Plasma Cannons can add a safety net to your coverage. These can deal with smaller threats without risking your heavier hitters giving you some peace of mind for when XCOM decides to be XCOM and immediately throw a Battleship at you after you splashed a Small Scout.

As a final note, never hesitate to abort an interception, especially if you have more planes waiting in the wings, your interceptor is equipped with something stronger than Avalanche Missiles or your interceptor is a Firestorm. As long as the UFO dies, you won't have a problem with the Council, even if it takes all 4 Interceptors, and only if you have extraordinarily bad luck will you get a second UFO over the same continent before any of your interceptors are back on their feet.

See Also

• UFOs