Not exactly a radio call, but if you hit and release the mic transmit button twice it's the same as saying "I copy". As an example: "Delta 2, Charlie Charlie bird, can you get that 190 just north of 14?". All you have to do is tap the mic button twice to say "Yep, I'll get 'em".

Abort = Stop doing whatever it is you're doing. Always followed by additional instructions
Ackstar = A pilot flying a bomber near a field and using it as an airborne anti-aircraft battery. Most pilots don't like people to do this, as it is not historical and it removes some of the fun from the game. Not to mention that doing this makes you the primary target in the area.
Alpha charlie = Aircraft, used with o'clock calls
Alpha is up = Alpha group is airborne, replace Alpha with your group name
Alpha Mike Fox = Adios Mother F*%@$%, or Adios My Friend.
Angels = Altitude. Angels 15 means 15,000 feet.
Approach low = Get lower than the enemy fighters and fly to them from a lower altitude
Approach high = Get higher than the enemy fighters and fly to them from a higher altitude
Armed = Safe/hot. Current weapons status, also refers to current attack status. e.g. "Cleared hot" or "Guns cold".
As fragged = Attack will go as planned/briefed
Bandit, Tango = Bad guy
Back to the taxpayers = Where wrecked aircraft go
BDA = Bomb-damage assesment. Having someone check the damage you did after a run. Called like this: "Delta 2, charlie 5, request BDA over".
Banzai = Commence decide and launch attacks against enemy positions. Hearing a flight lead call Banzai means there's plenty of targets to go around. Attack, ingress, egress, weapons release, and target choices are all up to the individual pilots.
BARCAP = Barrier Combat Air Patrol. Nothing gets past the barrier of your fighters without being shot at.
Belly check = A quick roll to check below your aircraft for targets or landmarks. e.g. "Flight, lead, belly check"
Bent = Something on your aircraft is broke, or just plain don't work. e.g. "Lead, two, radiator bent"
Betty, Bettyies = Japanese G4M bomber
Bingo fuel = You're almost out of gas. If you go past bingo fuel when you're in a fight, you won't have enough gas to fly home. "Bingo plus ten" means you've got ten minutes before hitting Bingo fuel
Blind = No visual on anything
Bogie = Unidentified aircraft, NOT a valid target. Engaging Bogies, as opposed to Bandits, means you haven't properly identified your target.
Boogered up = Slang meaning your aircraft is all beat up. Borrowed from racing
BRAA = Bearing, range, altitude, aspect. Control format used by FAC/friendly aircraft telling you what's going on with the enemy. An example would be "Whiz lead, FAC, target BRAA 030, 15 at angels five, 60 left". In english: Bearing from you is 030, 15 miles distance at five thousand feet, target is approaching you at an angle of 60 degrees left. At 90 left you would see the enemy plane's left side (9 o'clock). Some prefer to use the clock position instead of aspect, like so: "Whiz lead, FAC, target BRAA 130, 22 at angels 12, right 5". Remember, the angle given is not the angle from you, it's the angle you'll see the enemy from. Still confused? At 90 left you'll see the full left side of the enemy plane. At 30 left you'll see the front-left side of his plane. At "right 5" you'll see the right-rear of his plane. Get it now?
Bravo zulu = Well done, nice job, way to go, etc...
Break, Break!! = Get out of the way or turn fast E.G. "Break right!!" etc...
Brevity = Directive given by flight lead to cut down on radio chatter. If you hear this you need to stop rambling over the radio and start making quick, informative calls.
Buff, Buffs = Bombers, used with o'clock calls. Stands for big, ugly, fat, f*^$
Bug out = Run! Always followed by a direction. e.g. "Flight, lead, bug out 180!" tells the flight to break hard to heading 180 and run like hell
Bullseye = Reference points on a map pre-determined during the briefing for each flight. Fighters operating near an enemy field might use the field as a Bullseye point. Calls using Bullseye are given in BRAA format from the Bullseye point, like so: "Cheez whiz, check Bullseye six: bandits 065, 12 at angels 7." This means the bandits are on heading 065 from Bullseye 6, 12 miles away from it at seven thousand feet. Probably the fastest way to pass contact information from one flight group to another.
Buster = Full throttle. This is a call only given when you have to get somewhere, or do something, right-the-hell-now.
Button = Change frequencies/channels. Buttons are always given a number, so any pilot will have a list of "buttons" they can switch to.
CAP = Combat Air Patrol
CEP = Circular Error of Probability. The theoretical circle a bomb will fall into after being dropped on a target. "CEP zero" is pilot slang for a direct hit. If you've got surveilance vehicles in the area, they might report: "CEP zero, impact with high-order detonation, have a nice day!".
Charlie charlie bird = Command and control aircraft. Usually escorted by new pilots and containing the officer controlling the entire fight. Shoot it down and you might mess up the enemy plan.
Check fire = Cease fire immediately and double check your target to make sure it isn't friendly
Check your 6, check 6 = Enemy fighter behind you
Cherubs = Mini angels, or altitude in hundreds of feet e.g. "Cherubs 2"
Cold = Weapons status. e.g. "Guns cold" means you won't fire.....yet
Combat dump = Taking a crap before you saddle up to kill stuff
Commin' through! = Get the hell out of my way!!! A call made by a pilot who has an enemy on his 6 and no other place to go. Usually followed by a direction for you to go. E.G. "Hotel 4, Bravo 3 commin through. Break right." tells you he wants you to break right to let him come through
CMFIC = Chief mutherf*^$@% in charge. Usually meant to describe someone who likes giving orders but doesn't like taking them
Continue dry = You can keep doing what you're doing, but punching off rockets or bombs, or firing your guns, is not authorized. Usually flight lead gives this call to overly aggressive pilots going down on a quick scout run.
Cover = Keep an eyeball on, and take up a position to possibly attack a specific target; i.e. "Three, lead, cover bandits north-west".
Darts = Rockets. Also called rox, rocks, arrows, etc...
Decoder Ring = Cipher key for the radio codes
Delta delta = Dick dragger, a very hard fight
Delta Sierra = Dumb shit. If you got any "Sierra Hotel" or "Bravo Zulu" cudos, kiss 'em goodbye!
Deploy = Take up pre-briefed formation spots. A number is assigned to a given formation type (echelon, line astern, line abreast, etc...) which is given after this call. i.e. "Flight, lead, deploy five".
Dead dino juice = Fuel. Since most of the aircraft in any WW2 flight sim were retired before most of us were born, people refer to them as dinosaurs. Dead dino juice is what they run on.
Goon = C-47 Dakota cargo/transport plane.
Dope = Info. "Bogey dope" is a request for enemy aircraft info
Divert = Fly to the alternate target/mission plan/field
Dragging = Enemy aircraft following you between your 5 and 7 o'clock
Drift factor = "That guy has a drift factor of about 9.5!" Describes a person's lack of attention span.
Element = Two aircraft in formation
Engage = Attack a specified target.
Eyeball = Aircraft with the primary visual on target. e.g. "Hotel 3 is eyeball"
Expedite = Hurry the hell up! Used when something has to get done yesterday
FAC = Forward air controller, the guy who owns a chunk of sky/ground and directs the aircraft or ground units. As opposed to a FGC, or forward ground controller. In Aces High this is either a guy in an M3 or M16 calling contacts and directing pilots.
Fangs out, hair on fire = A common state of being for fighter pilots.
Fangs in floor boards = A pilot who got too ballsy and ended up getting shot
Feet wet/dry = Over water or land. e.g. "Joker flight is feet wet"
Finger fire = A pilot who has become overloaded in their attempt at getting the aircraft trimmed by working all three trim tabs at once. Thus over-trimming in every axis, making re-trimming necessary and possibly inducing smoke to rise from their soon-to-be sore fingers.
Flak = Anti-aircraft artillery. From the original German phrase flieger-abwehr-kanone
Flies = Pilot slang for Japanese aircraft. It was meant to give the impression that the Japanese aircraft are nothing more than very annoying.
Fox mike = F*@^^$# magic, how something amazingly complex manages to work.
Furball = A highly confusing, tight, swirling mass of friendly and enemy pilots bent on killing each other. A typical fight in any online flight sim.
Gopher = An enemy/unknown aircraft trying to fly under your flight in the opposite direction. When attacking ground targets, it refers to a tank/half-track going into a stand of trees.
Gorilla = Large flight of unknown/enemy aircraft. e.g. "Lead, three, we got a gorilla at 3 o'clock!"
Golden BB = The one, seemingly mystical, shot that gets you
Grand slam = Informative call saying that all enemy aircraft in the area are now on the ground in many pieces. Typically the last aircraft to get a kill will call it "Whizzer lead, three, we hit a grand slam!."
Greyhound = In USAF brevity, this indicates an enemy cruise missile of some sort. In WW2 flight-sim jargon, this means a fast moving bandit with short endurance. Usually taken to mean either the Tempest, Typhoon, Me-262 jet or Me-163 rocket plane. More often than not, it refers to the Me-163.
Hard (turn direction) = Turn hard. e.g. "Hard right!" etc...
Head on a swivel = Keeping an eyeball out for any bad guys. Also called doing a "linda blair", from her head trick in the Exorcist
Heads up = There's something of interest going on. Called as "Lead, four, heads up! Two bandits my right five."
Helmet fire = A mentally-overwhelmed pilot. Typically one who is: attempting to spot the target, trim the plane, worry about the other forty-odd aircraft in the area, remember the sight picture for a proper bomb drop, calculate remaining fuel in minutes, make sure the correct weapon is selected, and not fly into a flak trap. Naturally, this creates a mental train wreck. Such a pilot is said to have smoke billowing out from under their helmet as their overloaded brain attempts to make sense of the chaos. Thus, helmet fire.
High = Higher than you, used with o'clock calls
Home plate = Your primary landing field
Hotel Alpha!! = Haul ass, come quick!!
Hot mike = Everyone can hear everything you say because your mike is always on
Ident = Requesting info about the identity of something.
IFE = In-flight emergency
Iron hand = Strikes against AAA emplacements
Jabo [Yabo] = German slang for fighter-bomber. the entire phrase is Jadgbomber
Jackal = FGC in a ground vehicle well behind enemy lines. Sometimes used as a spotter near enemy airfields to call contacts and direct fighters.
Jagdgruppen, JG, Joker Golf = German flying units
Jerry, Jerries = German aircraft
Jink = A mess of random maneuvers used to defeat a gun shot. e.g. "Hotel 4, lead, jink!"
Judy = You can see the correct target, are in a position to kill it, have appropriate weaponry on board, and need a quick situational check before you strike. i.e. "Nail 4-1, Whiskey lead, we are Judy". The FAC/recon will shut up while you get your bearings and start making attack passes. If they happen to see something of importance, they'll holler. Otherwise the freq is your's.
Jug = Nickname for the P-47. it looked like a milk jug turned on its side.
Joker fuel = You've got enough gas left to turn back and land at either the field you took off from, or the alternate field. Without dumping your external ord
Knife fight in a phone booth = A fight with any tight turning aircraft at low speed.
Knock it off! = Stop all air combat training, maneuvers, attacks, defensive moves, and form up for further instructions. Only used in training.
Low = Lower than you, used with o'clock calls
Lowdown = Asked when you need to know the "big picture" for a given area. Requesting this from a FAC will usually get you all pertinent tactical info in the area. Get out a pen to take notes and pray you have enough fuel; in a busy AO, you might be copying stuff for a while. Usually pilots will ask for the lowdown on either air or ground targets to keep chatter down.
Luftwaffe, luftie = German flying corps. The later is used to describe pilots of German aircraft
Miller time = The last man off target in an air-to-ground strike will say this when the final target is dead. If you were flying a rescue CAP, it means all survivors have been picked up.
Mud mover, ground pounder, gropo = Ground attack aircraft.
My fun meter is pegged = A highly sarcastic comment meaning you hate this
Nine Line = The "nine lines of info" needed before hitting ground targets. Usually only employed by jet-powered aircraft. The brief must contain the following info:
1. IP (initial point; either pre-agreed upon grid or large terrain feature)
2. Heading to the target
3. Distance to the target
4. Target elevation above sea level
5. Target description
6. Target coordinates (grid ref, lat/long)
7. How the target may be marked (crater, smoke, distinguishing terrain feature)
8. Location of friendlies (if any)
9. Egress direction
    In practice, it looks like this:
IP Tango, 186 for 12, elevation 1-5-0-0, three flak tracks, grid 6-8-7, multiple craters, no pals, West pull-off.

    Translated, that comes out to "Fly towards that big snow-capped mountain. Once you're over it, fly a heading of 186 for 12 miles. The target is at 1,500 feet, a trio of AA vehicles in map grid 6-8-7 just look for the cluster of craters. No friendlies are in the area, and after you make your run turn West."
    Any additional info can be included, such as the reason for a West pull-off or why the runs shouldn't over-fly the target (a bad idea, anyway!).
No joy = No visual on target/friendly. e.g. "Hotel 3, lead, no joy"
Nordo = Just say it, Nordo. Short for No Radio.
Outlaw = An enemy aircraft has closed to the point where Rules of Engagement (RoE) are satisfied. The call should include the number of outlaws, rough heading, altitude, and clock position as you see it. Almost always answered by flight lead with "Engage".
Padlocked = You can't take your eyes off the target without losing it. e.g. "Two, lead, come off high right and orbit"...."Neg lead, two is padlocked"
Plumber = A pilot who isn't fit to read a manual, let alone fly
Pogo = Change frequencies. Always stated: "112.5 pogo 118.9". Meaning change radio freaks to 112.5, if you don't get anything, try 118.9, and if that doesn't work, come back to the original channel. Classic brevity code, as you convey a whole sentence with a few words.
Pop = Again, classic brevity. "Flight, lead, pop!" is a short call indicating you should start a max-rate climb from weed-level up to at least medium altitude. Usually used when attacking ground targets.
Pucker factor = A measure of how scary something is by how tight your ass gets. Some pilots who hit the legendary "10" on the scale claim to have left fang marks in the seat
Play time, how long can you party = Asking how long you can stay over the area. A C&C bird or a FAC might ask "FAC, delta 2, how long can you party? over". He wants to know how long you can stay over the area before calling Bingo.
Pistol = Guns. "Full pistol" means a full ammo load for the guns
Posit = Position. The answer always includes a landmark or a grid reference to make getting there easier
Post hole = A diving spiral
Press = Continue the attack. To steal VP's example on SimHQ "Two, lead, tally visual press!" means "I see you, I'm supporting you, you're clear, keep up the attack"
Receiving fire = Someone shooting at you
Reference = Turn to the specified heading. e.g. "Flight, lead, reference 220"
REMF = Rear echelon mutherf*^$@%. Used to describe pilots who don't fly in combat or people who signed up to be clerks. Combat pilots will trade small war trinkets for favors that the clerks can pull off. Calling a pilot a REMF is a pretty big insult
Roger, roge = I understand
RNO = Results not observed. An actual call might go like this: "Delta 2, charlie 5, dumped one pair of 500s on-target, RNO." Usually followed by a request for a BDA
RTFM = Read the f&#$%^ manual!
Romeo Foxtrot = Rat f#@$. Higher ups getting into and commanding combat assaults. Usually ends up killing more good guys than bad guys. Send them to my tactics page for help.
Romeo Tango Bravo, RTB = Return to base
Romeo triple delta = Really deep doo doo, a very bad situation
Scram = Find a hole in the fight and run like hell for friendly territory. Usually given when the flight lead sees a gorilla and has no choice but to call Scram or get everyone killed.
Scrub = A rather low and very slow aircraft, typically a C-47 trying to sneak in under radar.
Secondary/secondaries = Explosions that follow the initial detonation of air-to-ground ordnance. Usually due to fuel/ordnance being in the lethal blast radius of a bomb/rocket landing close by.
Sidestep = Change from primary to secondary. "Sidestep vox" means change to the second frequency. "Sidestep bandit" means attack the guy's wingman/leader, "sidestep alternate" means land at the back-up airfield.
Shack = Direct hit
Shooter = Designated hitter in the "shooter eyeball" element. e.g. "Two, lead is with you eyeball/shooter, number two shooter, call the shot". Lead is flying the eyeball position (high and off to the side for better visual), #2 is the shooter. With lead holding high and away he can get down to help two if two gets into any trouble. Plus, two can get info from lead as to what/where things are happening.
Shopping = Looking for a target. A CAP flight would call it as "Nail 4-1, Cheez-whiz lead, we're shopping for bogies today". A smart-ass FAC would then answer "Roger and good morning K-Mart shoppers! We've got a blue-light special north-east of Alpha-11 on bogies today".
Shotgun = The point in the mission where you've reached a certain ammo/weapons status. Most often, Shotgun is called when you've expended air-to-ground ord and still have enough bullets for a short dogfight. Quite often a mission will RTB once the Shotgun point is reached, especially if you're expecting enemy aircraft on the way home. Can also be called in a dogfight if you get low on, but not run out of, bullets. Similar to calling Joker fuel.
Sierra Hotel = Shit hot!
Sliceback = Break into a decending turn (usually a 180) to this heading. e.g. "Four, two, sliceback 330!"
Skip it = Request to engage denied. Always followed by other instructions
Skunk = Unidentified contact on the water. Ships, PT boats, life rafts, fishing boats, freighters, and canoes are all Skunks until you find out just who owns 'em. Once you find that out, they might be reclassed as targets.
SLUF = Short little ugly f*^$@%. A nickname for the F4-U Corsair.
SNAFU = Situation Normal: All F&#^!@ Up
Snap = Turn to this heading right now. e.g. "Flight, lead, snap 270"
Snuggle = Aircraft in very tight formation e.g. "Flight, lead, time to snuggle up"
Spuds = Bombs. Also known as eggs
Status = What are you doing? e.g. "Two, lead, status"...."Two engaged offensive with three bandits!"
Step on the ball and trim it up = Fly correctly, and quit screwing around
Step on it = Hurry up
Stranger = Unknown (bogie) aircraft that is not part of the action.
Switch = Changing targets from one enemy aircraft to another for some reason
Tail end charlie = The last man in formation, a good place to be when going to a fight, a bad place to be when coming home. Good when you're going to a fight because you still have time to run and not get spotted. Bad when you're coming home because the enemy will kill you first, or you'll be the last one landing with the least amount of fuel.
Tally = Visual on enemy formation/aircraft/ground target. Saying "Tally ho! Bandits!" is redundant
Tally on xx bandit\tango = I see xx enemy aircraft. Used with o'clock calls
Taking hits = Someone putting holes into your plane
Tango uniform = Tits up, something got broke
Tin horn, green horn, newbe, Gregory green ass = Slang for new pilot
Tumbleweed = No visual, no tally, and no info about the situation. e.g. "Lead, three is tumbleweed"
Visual = I see friendlies/you
Wailer = Jet planes. a.k.a banshees, screamers, zoomies
Warm fuzzies = The feeling of security a pilot gets from an aircraft, or some feature of the aircraft
Weeds = Really low altitude. e.g. "Two, four is in the weeds offensive with one bandit"
Weed whacker = Prop planes
What luck = Typically called by flight lead to find out how everyone did. Your response should include any kills, recon data, or visual sightings.
What state = Info call requesting your ammo/fuel state and damage if any. e.g. "Four, lead, what state?"...."Four has full pistol, 90 mikes fuel, no dents". Fuel info can be given as either minutes remaining or gallons remaining. Saying you have "half tanks" or something similar doesn't tell flight lead how much longer you can stay in the air.
Whiskey charlie = Who cares?
Whiskey delta = Weak dick, a pilot who refuses to engage the enemy, fails too often, or just plain sucks. Calling anyone this is the height of insults
Wilco = will comply
Winchester = You ran out of ammo appropriate to a specific type of target. If you were attacking tanks and dropped all your bombs, you'd call "Nail 4-1, Cheez-Whiz lead, we are Winchester spuds".
Words = Mission info. e.g. "Joker 3-3, Hotel lead lookin for words"
Zapped = Someone or something got blown up or shot down E.G. "I zapped that guy"
Zeke, Zekes = Japanese A6M Zero
Zipper = Another word for "roger"
Zippo = Fireball, usually used to describe an enemy aircraft on fire. "Zippo comin' down" is a call that means an enemy aircraft is on fire and spiraling down towards the rest of the group. You might want to get out of the way after looking up. Also nickname of the Japanese Zero, it caught fire very easily.