Things that can be launched , fired or dropped from aircraft, whether it's a balloon, airship, fighter, bomber, or helicopter. Also includes equipment to make an aircraft more effective or countermeasures to air-to-air weapons and equipment to make an aircraft more effective. Note that this article does not include ground-launched or ground-fired anti-air armaments.
- It's time to get medieval, I'm goin' in for guns.- Dos Gringo's
The first form of anti-air combat, along with cans attached to wires (to foul an enemy's propeller), was small arms and then light machine guns. It started when scout planes, the only type used before the Great War in a combat role, would bring pistols or small rifles in case they met an enemy scout plane. Then some pilots started fitting light machine guns to their planes, and it escalated from there. Given that WW I-era planes had big wooden propellers mounted in front of the cockpit, firing through the propeller at first posed an obstacle, because if you fired your light machine gun (LMG), you'd put bulletholes in your propeller. Then a Gadgeteer Genius from The Engineer corps figured out a timing chain that linked the LMG mechanism to the engine, and fired only between strokes of the propeller.
From World War II onwards, for guns and cannons to be effective against enemy aircraft, bombers in particular, they needed to be either very large calibre like .50 cal or 20mm, or you need a bunch of fast-firing smaller weapons, such as the eight .303 Vickers K's on the Spitfire and Hurricane. This lead to the revival of rotary cannons as the fire rate to damage, or to even hit, an enemy increased dramatically. Plus with the rotating barrel approach, the non-firing barrels have time to cool, so they don't melt.
While some ground-attack aircraft used 40mm cannons for firing on tanks, analysis after the war showed that somewhere between 20mm and 30mm seemed to be optimum in this role, especially if they contemplated using them against large bomber aircraft that could take a lot of damage and keep flying. Most of NATO standardized on the ADEN (UK) or DEFA (French) high-cyclic 30mm autocannon for fighter aircraft, the mechanisms of which were copied from wartime German designs; the US went, after the Korean War, with an electrically powered 20mm Gatling gun that fires 100 rounds per second, still their standard today after more than fifty years of continuous use, with the caveat that some 2020s planes no longer have an autocannon. The Eastern Bloc went mainly with 23mm, then since around 1985, mostly 30mm autocannon of various designs.
At one point the US military (specifically, Secretary of Defense Robert McNamara) deemed guns outdated and built a series of jet interceptors (F-4 Phantoms) armed with only missiles, using AIM-9 Sidewinder and AIM-7 Sparrow guided missiles as their primary air-to-air armament, based largely on promises from the contractors that the then-new radar-guided air-to-air missiles under development would display unprecedented lethality and utility. After they took heavy losses in Vietnam to cannon-equipped MiG-19's and -21's, however (this due in large part to early AIM-7 radar-guided missiles being unreliable, and furthermore having been designed to be used beyond visual range—and indeed its guidance system required several miles of flight to pick up a stable reliable target lock—but in Vietnam the politically mandated rules of engagement required visual identification of every target, making the AIM-7 worse than useless, it was not only useless but also dead weight), they returned to adding Vulcan cannons as a backup weapon bolted on under the wings in "gun pods," and the F-4E variant that entered service in 1968 had the Vulcan cannon built in, with 1100 rounds of 20mm in its feed hoppers.note
These unguided weapons explode either when they hit something or when they've flown a certain distance. One of the most impressive of these is the Genie, a tactical nuclear rocket designed for shooting down bomber squadrons, though it is uncertain whether Soviet bombers approaching US airspace would have obliged by flying in conveniently vulnerable tight formations. note
They have been in use for decades, and some sources say the French experimented with them in World War I, but with mediocre results (it's dangerous to launch a rocket that exhausts vast plumes of white-hot flames from an airplane built of wood and cloth) at the time. During World War II, with the Germans making heavy use of them against Allied bombers, as their longer range and heavier warhead allowed for more destructive power with less risk. Some U.S interceptor aircraft designed in the 1950s carried launchers for large numbers of unguided 70mm rockets of a type normally used for air-to-ground use, instead of gun armament, on the theory that shooting down large Soviet jet bombers required more punch than even electric Gatling autocannon could provide.
With the advent of guided missiles, air-to-air rockets have been phased out, or retasked for air-to-ground use.
Infra-red guided missiles
- Fox Two!- Brevity code for firing one of these
AKA "Heatseekers", these are designed to home in on the engine exhaust of an enemy aircraft or just the heat generated by its friction. Before being launched, you need to have a lock on a target, indicated by a visual display and the characteristic tone (Beeeeeeeeeeeeeeeeeeeeeeeeeeepppppppppppppppppppp! or sometimes grrrrrRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR!) in the attacking pilot's headphones.
These weapons are short-range (as in, within visual range - less then 20, sometimes less than 10 kilometers), but they make up for this by being fire-and-forget (no additional guidance or action from the attacker), and, for a time, by being undetectable by the target — short of them (or their wingman) looking out the window and seeing an inbound missile — since they passively rely on the target's heat emissions rather than actively emitting radar.
Ironically, the exact same imaging method used to make these missiles undetectable is nowadays used to detect them: infrared-based missile approach warners pick up the heat signature a burning missile generates, identify it as belonging to a missile (as well as which make and model in more modern systems), and alert the aircraft's pilot.
Once detected, the defending aircraft can drop flares and try to trick the missile into tracking those instead. The success rate depends on the technology level of the missile (with early models being fairly easy to spoof), but any defense requires that the defender be aware of the missile in the first place. In situations where a pilot knows they are likely to be targeted by heat-seeking missiles — such as having an enemy behind them in a dogfight, or descending low enough to be targeted by man-portable missile launchers (MANPADS) — they may launch flares regularly as a preemptive countermeasure while they work their way out of the dangerous situation.
They are standard on all fighters today and many a strike aircraft. They come in five Technology Levels:
Can only be fired from a narrow (30 degree) area behind the target. This is fairly hard to do and requires a firing solution very similar to that of a firing solution for gun armament, though with the advantage of greater range. The earliest versions were created just after the Second World War and their circuitry was all vacuum tubes, no transistors. Their use in combat had mixed results at best. Under perfect circumstances they could be very deadly, but were also very unreliable because they were prone to losing target lock if, for instance, the reflection of the sun from the surface of a calm ocean happened to pass through the missile's sensor's field of "vision." They were also very vulnerable to flares and other countermeasures.
- The original AIM-9B Sidewinder
- The K-13/AA-2 "Atoll" the Russian copy, and many other 1960s-1970s Soviet air-to-air missiles, up through the IR-seeking version of the big AA-7 "Apex," had sensors like these.
These can be launched from a larger angle, but you still need to be behind the target. Tend to be smarter and more agile than earlier versions.
- The AIM-9 series starting with the -9D (for the Navy) and -9E (for the Air Force) that used cooled seeker heads for improved tracking. The -9D used compressed nitrogen, while the -9E used electric cooling.
- The R-60/AA-8 "Aphid" from the USSR, found on aircraft like the MiG-23 interceptor, also at least theoretically mountable on some models of the Mil-24 "Hind" helicopter gunship
Sensitive enough to detect and get a reliable lock on the leading edges of the wings, which are heated by air friction from flight at jet speeds, they can be fired at the target from any angle provided you have a good shot. It's much harder to avoid too.
- The US AIM-9L, known as the "Wish Me" by Harrier pilots in the Falklands because it was so effective, they just needed to "wish" the target dead. Current mass production version is the AIM-9M, said to be just a little smarter and more agile than the L.
- The IR-guided version of the Soviet AA-10 "Alamo" was believed by Western experts to be in this class. This is a good place to note also that the Soviets in many instances designed air-to-air missiles with a certain "chassis" of solid rocket fuel engine, fuselage, and warhead, and then manufactured both a heatseeker and a radar-guided version, to offer their pilots greater tactical flexibility; typical loadouts might be two IR-homing plus two radar-homing.
The problem with the older missiles is that you need to be pointing your nose at a reluctant target. With these, coupled with a Helmet-Mounted Sight, you just need to look at a target (up to 60 degrees or so off your centre-line) and fire.
- This technology was developed by the US in the mid-1970s as a result of analysis of air combat in Vietnam, analysis of existing systems, and large-scale wargames and then abandoned for decades as it was felt to be too expensive to be practical, except for some small-scale trial use by the US Navy in the late 1970s.
- The latest version of the AIM-9 Sidewinder, the AIM-9X, has off-boresight capability, with a full 90 degree search cone..
- The R-73/AA-11 "Archer", which entered Soviet service in 1983, is at least theoretically capable of use in this mode, but has never been used in combat, and at least some reports suggest that very few were ever manufactured.
- R-73s scored many kills during Eritrean–Ethiopian War, though one must those that such missiles were probably old stocks.
- The latest model of the Israeli Rafael Python, the Python 5, also has off-boresight capability, up to 100 degrees.
Can see "images" rather than single points of heat and can go for the more vulnerable targets rather than the exhaust. Considerably "smarter" than earlier designs, they are at least theoretically much less vulnerable to countermeasures like flares.
- The US/UK/Australia joint design AIM-132 ASRAAM, as carried by the Typhoon.
- The US AIM-9X.
- IRIS-T built by a German-led consortium.
- The French Mica-IR, designed for the naval version of the Rafale jet, is reported by some sources to have this capability
- The Israeli designed Python-5 allows the Pilot to designate an point of impact (or greatest fragmentation impact) on the target aircraft, including the cockpit.
Radar Guided Missiles
- "Fox One!"
These missiles guide in on the radar reflections of a target and come in varying forms. Although longer range (typically beyond visual range, or "BVR"), they have the disadvantage that any pilot equipped with a functional Radar Warning Receiver (RWR) will almost always know some combination of the following details:
- The launching platform (airplane or surface installation), its approximate model and capabilities, the direction it's in, and its approximate range (based on signal strength);
- The exact moment of launch(es), since most fire control radars change to a distinctive mode at the moment of firing;
- The bearing and approximate distance of the missile itself, if/when the missile switches to its own radar.
Radar-based missiles are defended against using chaff, a cloud of small metallic particles that creates a much stronger yet much more confusing radar return than the airplane itself. This is very commonly used in combination with turning to put the launcher to the direct right (3 o'clock) or left (9 o'clock) of the plane, and (if lock cannot be broken) turning hard towards the missile at the last available moment. Flying laterally helps reduce returns from radars that depend on the doppler effect of the plane moving forward or away from the radar, and also requires that the missile "lead" the plane to account for the fast lateral movement. Turning hard at the end requires that the (now low on fuel) missile quickly cancel that lead and fly at the plane head-on, and it must do so in the very brief window before it passes behind the target plane and becomes useless.
These missiles ride a radar-beam towards a target. The beam is controlled by the launching aircraft, which must keep the beam on the target for the entire flight of the missile. As most aircraft will not obligingly fly straight and level once they realize they are being targeted, and the launching aircraft is also likely to be maneuvering wildly to avoid counterattack, this is a very unreliable system and these missiles were soon surpassed. On air-to-air weapons, These are mid-1950s technology.
- The Soviet K-5/AA-1 "Alkali"
- The US AIM-4 Falcon.
- There were also tail-chasing infrared homing and semi-active radar homing versions of the AIM-4 Falcon, a small number of which were used in Vietnam. Their performance in combat was extremely unimpressive, and they were dropped from production in favor of the newer AIM-7 and AIM-9.
These missiles home on a radar reflections from a target aircraft that is being "painted" with the radar system of the jet fighter that launched the missile (tactics were developed for one aircraft to illuminate the target while another fired the missile, but it is uncertain whether this was ever tried in actual combat, and this general category of guidance system is now obsolescent). This does of course require the firing aircraft to retain a lock on it, which is by no means easy if the target aircraft is maneuvering. This generation of radar-guided missiles was the first to have circuitry included that made them smart enough to home in on a radar jammer. These were introduced around 1960 and have been obsolescent since the advent of reliable active radar homing missiles in the mid-1980s.
Note that this homing scheme is still relevant and commonly used in Surface-to-Air Missiles fired from ships and land sites. The chief disadvantage as an air-to-air guidance scheme (that the attacker has to follow the target around while "painting" it with radar) is not an issue for a large land installation or ship that has large radars that can look in any direction, and it allows for cheaper and simpler missiles to be used to the same effect. That in turn allows each site to have more missiles available for the same space and money.
- The US AIM-7 Sparrow (early versions like the AIM-7D and AIM-7E used in Vietnam were mediocre performers, the late-production AIM-7M some US Air Force and US Navy fighters used in the 1991 Gulf War were much better performers, not only because the technology had improved, but also because they were no longer being used under restrictive rules of engagement requiring pilots to hold their fire until they were so close to the target that the missile could not lock on) The "Aspide" manufactured in Italy is an improved copy built under license, still in service.
- The short-lived AIM-9C version of the normally IR-guided Sidewinder missile, intended for the F-8 Crusader as it couldn't carry the AIM-7. Most were rebuilt into AGM-122 anti-radiation missile in the 1980s.
- The Soviets had a radar-guided version of the AA-2 "Atoll" using this technology.
- Soviet AA-3 "Anab"
- Soviet AA-4 "Awl"
- Soviet AA-5 "Ash"
- Soviet AA-6 "Acrid"
- Soviet AA-7 "Apex" (this and the AA-6 were very large, heavy radar-guided missiles carried by jet interceptors, intended for use against large American bombers; they were by far the most common missiles of this class produced, at least in Eastern Bloc service)
- Soviet AA-10 "Alamo" had a radar-guided version with this technology, along with an all-aspect IR seeker version
- Britain's Skyflash is another enhanced Sparrow clone, still in service today.
- "Fox Three!" (or with a distance attached, e.g. "Fox Three Long!")"Pitbull!" (called once an AIM-120 has switched to the missile's own guidance)"Maddog!" (called when launching an AIM-120 without a lock and letting it lock on the first target it sees)
These missiles have their own radar seekers on board to carry out the final intercept, allowing them to be launched from long distances and left to do their job (leading to them being termed as "fire and forget" missiles). With some aircraft, one plane (or an AWACS) can light up the aircraft and guide missiles from multiple aircraft in before the missiles go active. This sort of guidance system is also very common on anti-ship missiles.
- The US AIM-54 "Phoenix," developed in the early 1970s, noteworthy for having an effective range well in excess of 100 nautical miles, possibly the longest-range air-to-air missile ever produced. It and the F-14 "Tomcat" jet fighter that carried it were developed concurrently. As far as can be determined, it was never used in combat by the United States. This site asserts that the Iranian Air Force scored several kills with the AIM-54 Phoenix during the Iran-Iraq war, including MiG-25s and one occasion where a single missile destroyed three of four MiG-23BNs flying in close formation.
- The US AIM-120 AMRAAM, also called the "Slammer". It was developed in the late 1980s, and while it entered service just a touch too late to see action in Desert Storm, come Operation Southern Watch one year later it proved to be as lethal as the contractors had promised the AIM-7 Sparrow would be thirty years before. Current production version is the AIM-120C with an effective range of 30+ miles, and AIM-120D, with a 65+ mile effective range, is currently in the testing and evaluation stage of development. Smart, agile, and highly lethal, it appears to be everything they promised radar-guided air-to-air missiles would be back in the 1950s.
- Soviet AA-9 "Amos," similar in role to the AIM-54 Phoenix.
- Russian AA-12 "Adder," though publicly available information about it is almost entirely speculation and rumor, at least in the West; some sources describe it as comparable or superior to the AIM-120—indeed, the Adder is sometimes nicknamed the "AMRAAM-ski".
- The under-development Meteor system for the Eurofighter Typhoon
- The French Mica-R air-to-air missile developed for the naval version of the Rafale has this technology.
- The Russian Vympel AA-X-13 "Arrow" is reputed to have an operational range of up to 215 nautical miles (dependent on the shot profile). It was designed to target an enemy's AWACS, JSTARS or Airborne Refuelling Aircraft without having to fight through the accompanying fighter escourt. In a similar vein in the Novator K-100 (formerly K-172 AAM-L), which is being developed by Russia and India.
While jetcraft have yet to be shooting each other out of the sky with Star Wars-type lasers/whatnot, this shows use on a large airborne craft (read: modified jumbo jet) for shooting down ballistic missiles on their way up, and in theory could work against an aircraft too by detonating its fuel and weapons load.
Of course, in order to hit an ICBM in boost phase, you'd need to station your YAL-1 quite near its point of launch, something about which your putative enemy's interceptors might have a point or two to raise — and since "YAL-1" is a fancy name for "converted Boeing 747 wrapped around a big-ass laser", odds are you're going to have some trouble keeping it in one piece long enough to justify the extremely large amount of money you've spent on it. Despite its partisans' desperate search for other potential applications — such as the half-baked idea of using it to shoot down other aircraft, pretty much all of which are more agile than the YAL-1 platform — the program was cancelled in 2011 for the costly boondoggle it was, and good riddance.
In general, directed-energy weapons are to the military what true general artificial intelligence is to computer science: both are fifty years in the future right now, just like they were fifty years ago, and just like they'll still be fifty years from now.
'Iron' means there's nothing really special about these. You release, the bomb falls, and (hopefully) it blows up what you aimed it at. The first ones of these, at least according to The Other Wiki, was from unmanned balloons sent over Venice. Not many hit. Then again, this was 1849.
Most bombing was done by letting the ordnance drop and just free-fall down to the target. Very difficult to avoid, but also difficult to aim—this is why the main methods were either to divebomb (ride the bomb a slight way to the target in a dive, centering the target in the gunsight before releasing; can be very accurate, especially if the pilot waits until the last possible moment to drop the bomb and pull out of the dive, but also extremely dangerous to the pilot) or to carpet bomb.
The former limits it to high-performance (and low payload) aircraft; the latter tends to be hit and miss and miss and miss and hit and miss, which can get messy if you only have a single thing to destroy. On the other hand this can be a useful tactic if you have a known location for a large enemy unit on the ground; in Korea the US used B29 bombers to carpet-bomb Chinese units massing for human wave assaults, and since Vietnam has used the term "ARC LIGHT" to describe this use of heavy bombers to carpet-bomb the very bejesus out of enemy units on the ground, the term having originated with the semi-secret project to study the feasibility of using B52 bombers, designed originally to carry nuclear payloads, to haul many many tons of conventional "iron bombs," instead (30+ tons with some modifications).
Anything that helped with bombing was vital; according to at least one source, the USAAF's 'Norden' bombsight had one of the highest levels of secrecy, although it didn't quite live up to its initial hopes. The sheer inaccuracy of bombing with these things at night due to navigation problems (only one in five bombs ended up within five miles of the target) was a major factor in the British decision to area bomb German cities.
The third method is the "lob-toss", which involves chucking the bomb while in a climb. This was once regarded as only really accurate enough for nuclear delivery, where it also serves the purpose of giving you more time to clear the area. These days, however, with modern avionics and CCIP/CCRP HUD bomb sights universal since the 1980s in modern close-support and strike aircraft, a "toss" delivery can be very nearly as accurate as dive-bombing, even with "iron bombs." With smart bombs, this kind of delivery is usually good enough for the bomb's guidance system to take over and do the rest.
Another reason they are called 'iron bombs' is because most of their weight is from the steel casing, with less than half from the actual explosives. The aim of these bombs are not usually to kill from the explosion (though it is handy against armoured targets, or when the objective is to destroy, for instance, a vital bridge, or to make craters in the runways of an enemy air base) but to kill and wound from shrapnel which can be deadly from several hundred metres away.
Since 1965 some Western air forces have used "low drag bombs," a variant type of "iron bomb" that has a long, slender, pointed casing for maximum streamlining and minimum air resistance. This reduces drag on strike aircraft that are carrying them on external racks or hardpoints, permitting slightly higher speeds. They also fall faster with less air resistance once released, making them more accurate because they are less affected by wind; additionally they allow aircraft to dive-bomb accurately at shallower angles than older designs required.
There are also "retarded bombs." No, this isn't a comparison to smart bombs. These have some kind of parachute or balloon system built in to slow their fall, to allow the attack aircraft dropping them more time to get away; these are for very, very close, very, very low level work, for missions done at such low altitudes that the blast and shrapnel of the bomb would endanger the aircraft dropping it. They first appeared around 1970, in the form of the "Snake Eye" system, a set of fins that could be bolted onto an existing bomb that would open up like an umbrella as it was released by the aircraft.
To put things quite simply, incendiary bombs set things on fire. They are useful for destroying structures and against personnel.
A specific variant is napalm, a mixture of an incendiary substance and a gelling agent, which causes it to stick to targets. Napalm bombs are inexpensive containers of nastiness that an aircraft drops on target, lacking any particular guidance system other than the skill of the pilot, is napalm, basically gasoline or jet fuel mixed with a chemical gelling or thickening agent, put in a container with a fuzing mechanism designed to ignite it on impact as the contents splash out. Cheap, effective, and politically controversial, it was created during the Second World War and has been in very common use ever since.
These were first put into service around 1965, just in time for Vietnam. The FAE is deceptively simple. Imagine a half-ton canister of propane, liquified petroleum gas, or something similar. Imagine putting shackle points on it so that it can be slung on an attack aircraft's bomb rack. The canister will need to be modified, of course. Instead of detonating instantly when it gets to the ground, it has valves on it to release the contents and mix them with air in the appropriate proportions for rapid combustion, plus a time fuze to give the payload time to mix with air for a few seconds, plus a detonator or incendiary device of some kind to initiate the reaction, the reaction in this case being an enormous explosion that can kill everyone inside an underground tunnel complex beneath it by overpressure, or clear an instant helicopter landing field in triple-canopy jungle; they're also quite useful for clearing land mines. The designs have been refined over the years but the basic concept remains the same. Instead of a solid high explosive filling, they use a mixture of flammable vapor and air, or in some newer Russian designs, small particles of highly flammable solids in air, to create the big bang boom.
Everyone became an expert on this from coverage of the first Gulf War in the United States. It's Older Than They Think; folks seriously started looking into guided munitions after the Spanish Civil War and the Germans used radio-guided glide-bombs with some success in World War II. This is basically the idea of somehow getting the bomb itself to adjust where and how it falls based on what the aircraft is doing. Typical targets for "smart bombs" may include anything from the foundation of a bridge to a single individual armored vehicle to an enemy command post building.///
As discussed, there are a few different common guidance schemes for smart bombs:
Laser-guided bombs work by detecting the reflection of a laser beam that's shining on the target's location, very similarly to the way a semi-active homing air-to-air missile functions. The bomb has a set of fins that adjust its course until it hits. These are very precise and have been used to great effect in several wars since the 1980s, but they do come with the drawback of both requiring an aircraft to remain in the area to keep the target illuminated by the laser, and giving away that aircraft's presence and position to an enemy with the right equipment to detect the laser.
A command-guided bomb is guided by someone in the launching aircraft or nearby, who using a joystick or other controller steers the missile onto the target. Early command-guided bombs were more like radio-controlled gliders filled with explosives more than anything else; the operator had to literally look out the window of the launching aircraft, watch the bomb go, and try to steer it into the target. Later systems use infrared or television cameras mounted on the bomb to allow the operator to steer the weapon from its perspective. As with laser guidance, this requires someone to remain in the vicinity of the target for the weapon's entire flight.
This is a passive homing system where the operator uses the bomb's own television camera to lock onto a particular shape in the missile's field of view, which it attempts to hit once launched. It's targeted like a command-guided system but is "fire and forget". Early electro-optical seekers developed during The Vietnam War had a black-and-white TV camera and used an analog contrast seeker to detect the outlines of shapes to lock on to, while current-generation ones use digital image recognition software to home in on their target. The downside (at least for earlier models) is that the guidance system can be easily confused if the target is partially obscured, unevenly lit up, painted in a weird pattern or just shows up from a funny angle, which was why it was mostly supplanted by...
This is basically the same as the Electro-Optical system but the camera involved uses infrared radiation (heat) instead of visible light, and therefore is much less likely to be foiled by camouflage, darkness, smoke, or fog. As such, they're more useful, but more expensive, than an electro-optical system, although rapid advances in electronics tech eventually helped them win out in most contexts. The imaging infrared (IIR) guidance described above is a mix between the EO and IR systems, using digital image recognition to figure out what kind of object it's actually looking at.
Satellite GuidanceA new wrinkle from the Yanks is satellite-guided bombing, which comes in surprisingly inexpensive bolt-on kits for iron bombsnote . As long as they have the right target location, it gets hitnote (Sadly, this is still subject to human error—the Chinese embassy in Belgrade was hit by one of these due to an out-of-date map. The bomb did its job, but garbage in, carnage out.) GPS guidance is slightly less accurate than laser guidance, but the tailkits are cheaper than laser-seekers and the plane does not need to keep a laser pointed at the target.
Bunker buster bombs
These bombs are used specifically to destroy hardened structures. They have delay fuzes that explode them some time after penetrating objects, for maximum effect. They were developed during World War II, and have been in use ever since.
Another flavour of bunker-buster relies less on mass and more on sheer speed for target penetration: rocket-propelled bombs, initially a German specialty. Those things fall for a while, then a rocket motor ignites that launches them further downwards, through and under their intended target. Their casings are particularly thick to help them survive the impact, and the payload explodes after tunneling through. This kind of weapon is also very much still in use, with specimens ranging from the relatively small intended to be dropped in large numbers for destroying runways to the ludicrously large, guided ones meant to definitely kill a single bunker.
These occupy a place somewhere between "iron bombs" and "smart bombs" in both technology and application. It is basically a bomb casing that is designed to split open fifty or a hundred meters in the air over the target and discharge hundreds or thousands of "submunitions," basically grenades. They are extremely useful against dug-in infantry, and, with slightly larger shaped-charge submunitions, can damage or destroy even armored vehicles in the target area, as a tank's armor is generally thinnest on the roof. This idea is also Older Than They Think, having first been developed by the Soviets between the World Wars, copied by the Germans during the war, then developed further by all parties in the postwar era. Politically controversial because they tend to litter the area with duds which can render an area dangerous to civilians well after the end of a conflict. A notable example of its infamy was the massive drama created when Carlos Cardoen, a Chilean entrepreneur owner of Cardoen Weapons, sold this type of weapons to Saddam Hussein, though he argued that the transaction was well known for the US and it was done before the second Gulf War.
Some types of cluster munition can be used to lay minefields from the air, using land mines that arm themselves shortly after reaching the ground.
There are essentially two forms of deploying cluster munitions. The first is simple: fly a plane over the battlefield, push the launch button, and the weapon just drops a number of submunitions behind the plane. This is the easiest way to deploy the weapon, but also the riskiest for the pilot involved, since they need to be "in the line of fire". As a result, the second form was developed: the stand-off weapon. This is basically a missile that flies to a particular guided point, then does what the old dispenser would do: drops a lot of submunitions. This is much less deadly to the pilots involved (some SOW weapons can be launched from miles away, and there are even cruise missile variants, taking the pilot out of the equation entirely), but requires much more accurate technology.
Since 2000 we have seen the advent of cluster bombs with smart submunitions, which have sensors allowing them to seek out and destroy armored vehicles as they fall from above. These have been used in combat and appear to be every bit as lethal—and expensive!—as that sounds.
In 2008, the Convention on Cluster Munitions was signed in Dublin, banning signatories from using them, although many major states — notably the United States, Russia, and China — aren't signatories.
Unguided rockets are commonly found mounted to helicopters or light attack aircraft, you just aim at the target and let off a salvo of explosive rockets. They are most often used to shoot up lightly armed ships and road convoys, as well as to give fire support for the infantry when carrying out an airmobile assault. Prior to smart bombs and air-to-ground guided missiles, they were once the weapon of choice for close support aircraft, as the larger rockets had a chance to at least damage even the largest, heaviest tanks. They were a favored choice for ground-attack and close-support missions, as an aircraft that might only be able to carry a single 500-pound bomb could have racks under the wings for six or eight rockets. Rockets also pose less of a danger to friendly troops on the ground as their warheads are relatively small and so have smaller bursting radii.
They are typically mounted in cylindrical launcher pods, which are usually aerodynamically shaped to reduce drag.
Newer developments in technology have allowed for unguided rockets to be turned into guided micro-missiles, further improving their combat capability. Considering that the Hydra 70 pods on an Apache helicopter hold 19 projectiles each, and the Apache can carry three or four of those, the implications are obvious.
Airplanes and helicopters can provide quite a lot of dakka. This can be a strafing run from a Sopwith Camel's machineguns, up to the machinegun/cannon combo mounted on later Spitfires, then through the 30mm GAU-8 Avenger that the A-10 is built around. And then some—the AC-130 gunship ("don't think of it as an airplane, think of it as a flying castle of doom)" flown by the USAF currently mounts a 25mm Gatling cannon as its small gun. Also on board are a 40mm former ground-to-air cannon (now air-to-ground) and a 105mm howitzer plus extremely sophisticated sensors and fire control computers allowing it to find targets on the ground with great efficiency and engage them accurately.
These aren't limited to blowing up planes. Almost all the guidance systems above can be used to chuck a missile at something on the ground you don't like. One of the more fun variants is the homing antiradiation missile, meant to find and home in on radar antennae used by antiaircraft missile installations—especially radiation-filled radar sites. The USAF calls this sort of thing 'Wild Weasel' and the US Navy calls it 'Iron Hand.' Other air forces tend to use terms like SEAD ("Suppression of Enemy Air Defenses"). Since the aircraft is basically going for as close to a Scope Snipe as you can get with radar-seeking and radar-tracking missiles, some units adopted 'YGBSM' as a semi-official motto: 'You Gotta Be Shitting Me!' It used to be the case you could switch off your radar and make the missile "go stupid", but modern missiles can remember the location of radar sites, so your best option is to run for your lives.
The anti-shipping role requires someone to actually find the target, something that involves ships, submarines, other aircraft or satellites; it tends to be rather dangerous to just fly out and look for it and hope for the best, as naval vessels tend to be absolutely bristling with surface-to-air missile launchers and have bigger, better, more powerful, higher-performance radars than anything that's readily portable on the ground or in the air. Flying low to hide from radar amid the "ground clutter" doesn't work so well at sea, either.note And of course naval vessels also tend to bristle with anti-ship missiles also; analysts have called modern naval vessels "eggshells armed with sledgehammers," but that is perhaps a discussion topic for a different page.
Anti-shipping missiles (no, not that kind of shipping!) themselves tend to be very large, in some instances basically smallish robot airplanes in their own right ("cruise missiles" is one term for these), with very large warheads, for obvious reasons; these typically skim only a few feet above the surface of the ocean at just under the speed of sound or are launched from 150 miles plus and fly at stratospheric height. Sometimes "cruise missiles" are also used against land targets, such as airfields. Some "cruise missiles" and anti-ship missiles in the Cold War era had tactical nuclear warheads. This was an area far more studied by the Soviets than the Americans, who had the naval aircraft to do closer-ranged attacks.
From the 1930s onward, attack aircraft have been able to carry and launch torpedoes at ships, though these days it's much more likely to be a naval helicopter than a jet attack aircraft that makes the launch... and torpedoes don't just go in a straight line just under the surface of the water any more. From the 1960s on, torpedoes have had built-in sonar guidance systems that allow them to track down even submarines under the surface. Indeed, given the relatively short range and low speed of a torpedo travelling underwater (80km/hr is said to be barely possible for a few designs), compared to a guided anti-ship missile flying through the air (800km/hr is not out of the ordinary) and general fragility of the system—they must be lowered rather gently into the water—torpedoes launched by aircraft have since the 1960s been very much a specialized tool used almost exclusively for antisubmarine warfare. During the Second World War, a specialized type of attack aircraft, a "torpedo bomber," had to make a low, slow run in a straight line just above the ocean surface—an extremely risky tactic, as naval vessels even back then bristled with antiaircraft guns and tended to be protected by fighter aircraft as well—arm the torpedo, drop it into the water pointed at an enemy ship no more than a few hundred meters away, and hope that it hit the target. Nowadays hovering helicopters lower sonar search devices into the water and then send a homing torpedo (and homing torpedoes have existed since World War II, but were expensive experimental weapons then, with crude vacuum tube sensor circuitry and even preset search patterns encoded as punched holes on rolls of paper like a player piano; the homing torpedo did not come into its own as a weapons system until the 1960s) on its way when they have a likely target, which will almost always be a submarine.
American AirLand Battle doctrine during the Cold War envisioned use of large number of helicopter gunships heavily laden with, for some designs, up to sixteen long-range antitank guided missiles, for use not only as highly mobile antitank missile platform but also to go deep behind the forward edge of the battle area and attack Warsaw Pact second-echelon units before they got to the front. (However, the deep attack concept only was done at the tactical rather than operational level and Apache gunships with their Hellfire missiles weren't deployed in Europe until late 1987.) The Soviets also built helicopter gunships and armed transports but they were general purpose battlefield close air support platforms akin to a rotary Il-2 Shturmovik, as the antitank task fell upon other ground-based systems.
There have been, of course, multiple generations of antitank guided missiles, and many designs can be set up to be launched from aircraft as well as from vehicles. The earliest were wire-guided, circa 1960 (gunner squints into binoculars and attempts to steer the missile into its target with a tiny joystick on the first types, on later types gunner only has to hold the crosshairs on the target to make the missile home in on it). Then laser-guided designs appeared around 1980, requiring only the latter, hold-the-crosshairs-on-target guidance by the gunner, and can also be fired in indirect mode, in which the firing aircraft or vehicle lobs them over an intervening obstacle, such as a ridge line, while someone on the other side illuminates the target with a laser, allowing the firing unit to engage without a direct line of sight. Each of these systems had the disadvantage that the gunner could only control one missile at a time, reducing his practical rate of fire significantly—some have such long range that it could take half a minute or more to get from the launching aircraft to the target. Since the early 1990s, true fire-and-forget antitank guided missiles have been available, allowing, under ideal conditions, the gunner to engage targets as fast as he can get a positive target lock and send them on their way; these missiles are smart enough to do the rest themselves.
Guidance systems for air-to-ground guided missiles vary. Current trends for fire-and-forget systems are to imaging infrared TV cameras and high-resolution millimeter-wave active radar systems, interpreted by a small cheap onboard computer, but every imaginable system has been used. Laser guidance has the disadvantage of requiring target illumination but by the early 21st Century it has become very inexpensive indeed, at least for Western air forces.
And for fixed-wing aircraft specifically, in the early 1970s, the US Air Force and US Navy got the AGM-65 "Maverick" air-to-ground missile, early versions of which were television-guided by the operator. Over time the design got newer and better guidance systems, and larger, more effective warheads to the point where current versions (the AGM-65G) are fire-and-forget weapons with a range of many miles, sensors that can function in total darkness, a warhead that is comparable to the high explosive filling of a 500-pound iron bomb, and which is smart enough and versatile enough to follow moving targets, like an individual truck or tank, or to lock onto a particular building, or a parked aircraft, or track and strike a manoeuvring ship, as examples. Many other nations have weapons of approximately comparable capabilities in inventory, at least on paper. Some are much lighter and smaller, like the Brimstone (UK), allowing attack aircraft to carry significantly more of them, though the smaller ones, of course, lack the humongous warhead of something like an AGM-65G.
When training with bombs, sometimes an aircrew will use inert practice bombs. They weigh around the same, filled with roughly concrete, and are meant to act about the same, although without the environmental problems that blowing up a quarter-ton of explosives would bring, such as having to send people out to do the ticklish job of digging it up and destroying it if it turns out to be a dud. This still leaves some impressive craters. Then someone realized that if you can laser-guide a quarter-ton of concrete onto, say, a building, then what do you need explosives for? As an added advantage, this tends to kill fewer innocent bystanders.
Yes, the USAF is so obsessed with precision guided munitions that it laser-guided ROCKS. Wile E. Coyote would be proud.
Radio Detection and Ranging. Send out a radio pulse, find out when and how it gets back, and show a blip roughly where it is. It's pretty good at finding a chunk of metal flying through what's normally empty sky, although early radar wasn't as reliable. Radar's useful at sea, too, as big metal ships tend to stand out from relatively flat expanses of water. This started on ground to help detect incoming planes, but was developed so the planes could have a decent set. Not to mention AWACS aircraft that carry a BIG radar.
This was invented by the British and Germans in the late 1930s, pretty much independently and proved decisive in the Battle of Britain. The US independently developed this technology for naval use just before the war.
Anti-radar and Stealth
There's a few things you can do about the enemy having radar finding all your aircraft.
You can of course just sit there and take it, hoping to outperform the defences they can toss at you. A B-52 is very findable on a radar, but if it stays out of reach and keeps pelting cruise missiles at you, then you'll still have problems. The SR-71 Blackbird was meant to simply outrun interceptors and incoming missiles. The U-2 reconnaissance aircraft was believed to be capable of flying higher than any known existing Soviet surface-to-air missiles around 1960, but this turned out to be incorrect.
Then you could try to make the radar not work. Blowing it up is ideal (see the earlier Wild Weasel mention), but if that's not available, you can at least make it useless. Whether dumping chaff at a radar-guided missile or using jammers to mess up the radar signal, you're going to still be seen but not well enough to actually get hit. Hopefully.
The SR-71 mentioned above helped show another property. Properly made and shaped, some aircraft can look less threatening than others. This being the Cold War USAF, a lot of money was poured into the idea. The result: 'stealth'. Various tricks like shaping, radar-absorbent materials, and other stuff that I'm not cleared for. You have to keep one thing in mind though. Stealth is low observability, not an Invisibility Cloak. In practice it drastically reduces detection range of radars which can leave huge gaps in the defense grid, through which a stealth plane can slip through. In air combat the opponent also likewise has to come a lot closer before his radar can lock on. The only aircraft known to use it, so far, are these:
- F-117 Nighthawk. Called a stealth 'fighter', it's really just a ground attack aircraft. In service since the late 1970s, it started out as a top-secret black project initiated for the specific purpose of building stealthy military aircraft. It achieved that goal, and the plane would later be revealed to the public, and take part in the various wars of the 1990s and early 2000s with great success. However, one Nighthawk was nevertheless shot down during the Kosovo War, the circumstances of the event still remaining a topic for debate. Sadly retired in the late 2000s.
- B-2 Spirit. Called a stealth 'bomber', the Spirit really is a strategic heavy bomber, capable of striking anywhere in the world (with tanker support), passing through air defenses as if they were not there, and unleashing major destruction. The thing's cost is upwards of 2 billion US dollars apiece (literally, more than worth its weight in gold), and it's meant to really not look like any other bomber, whether you're looking at it with radar, infrared, or just your eyes. Visually, it appears to be a big black flying wing. On radar, it appears to not exist, unless you're using the ADF's Jindalee Radar that can detect it via the disturbances it leaves in the air behind it. So far, it has lived up to its purported capabilities in all its deployments, and the only B-2 loss until now has been due to a peacetime crash.
- F-22 Raptor. This one's a real stealth fighter, although it's hard to say how good it is. There aren't
many that can match it yet, and the US is pretty reluctant to talk about how well it works too. Just check out its description here to get some idea of what this bird is like. Sadly, only 187 were ever built, the last of which rolled off the production line in December 2011. It however is quite literally the Super Prototype of the...
- F-35 Lightning II. If the F-22 is the Cool Plane equivalent to Elite Mooks, then this is Demonic Spiders for enemy ground forces. Not as good a dogfighter as the F-22, the F-35's hat is ground attack similar to the F-117. It's real boons however are its VTOL capability, advanced ECM suite and comparatively lower cost when compared to the F-22: the US military ordered more than 2400 planes. Unfortunately, the project is plagued with delays (introduction in 2016 at the earliest) and overspending (the current projected costs of the program are 323 billion dollars).
- Sukhoi PAK FA T-50. It is intended as Russia's answer to the F-22 but it's still in the early prototype stage. According to the designers, it's less stealthy than the F-22 but more nimble.
- Chengdu J-20, another prototype stealth fighter design but this one's from - surprise, surprise - China. Its Chinese name fittingly translates as "Annihilator Twenty".
- Possibly the unmanned RQ-170 Sentinel, dubbed "The Beast of Kandahar" after appearing in photos on blogs and only recently confirmed as existing by the USAF.
Electronic countermeasures and electronic counter-countermeasures (ECM and ECCM)
Flares are what they sound like and are used to decoy IR-guided missiles. Note that newer generations of IR-guided missiles have become smarter and are less likely to be fooled by flares than they once were.
Chaff consists of strips of aluminium foil cut to a certain length (it's a formula involving radar frequency and the wavelength of the frequency that particular type of radar you're targeting uses) and chucked out in clouds from planes or ships to lure off radar-guided missiles, causing a cloud of thousands of phony "blips" to be created from the radio reflections thus created, at least until the aluminum foil bits fall to the ground.
And there are radar jammers, which are basically high-powered radio transmitters using the same frequency as your enemy's radar, which (you hope) will overwhelm his signal and cause interference, perhaps temporarily blind or even, if you are having a very lucky day, burn out his radar equipment. They have been standard equipment on ground-attack aircraft for decades now. However, radar-guided surface-to-air and air-to-air missiles have since the 1970s usually incorporated circuitry that allows them to home in on an active jammer, so leaving it turned on all the time is generally regarded as unwise. Ground-based radar jammers are likewise very likely to get a visit from aircraft carrying antiradiation missiles—see the section on anti-radar tactics above.
And many modern radars are "frequency agile" or "frequency hopping," meaning they jump from frequency to frequency many times per second according to a complex pattern that - they hope - airborne jammers can't figure out and jam.
Warning Systems and Electronic Support Measures (ESM)
It's useful for a pilot to know when someone's locked on to him or her. Radar Warning Receivers (RWR) and Laser Warning Receivers (LWR) can tell you if a radar or a laser has locked on to you with an audible tone in your headset.
More advanced RWRs (which are also mounted to ships) are systems that can tell you what type of radar is scanning or locked on to you, which generally narrows down enemy type a lot.
Unfortunately, RWRs and LWRs are completely useless when faced with Infra-Red (IR) weaponry such as the AIM-9 Sidewinder and R-27T Alamo.
The latest aircraft can use something called data fusion: put simply, they can collect information from other aircraft and use it to their advantage. For example, Plane A might spot an enemy aircraft (Plane B) and relay the data to Plane C, who can then engage the target using appropriate techniques.