Unmanned Combat Air Vehicles

UCAV's

"What the heck are UCAV's," you say! They are Unmanned Combat Air Vehicles, hence UCAV. They are intended to be unmanned aircraft that can participate in combat by carrying weapons, or do armed reconnaissance, operating over hostile target areas. They are the culmination of over 50 years of remotely controlled and self controlled (autonomous) aircraft. They have some interesting properties, some great aspects and some terribly stupid aspects. Interestingly, few of the features they promote are new, few of their problems a surprise.

A World Of Hurt

Air combat has always been a tough sport - People get killed. UCAV's are claimed to be the new way to stop pilots from getting killed, at least on the offensive side of things. Air defense systems are extremely tough to punch through with out great risk to the pilots of the attacking aircraft. In the post-Cold War era there are many countries that have been able to access ex-Soviet technology (and a few that got NATO tech too), to build effective air defense tiers and put the US's E.W. boys and girls onto perpetual overtime.

Systems like the E-8 JSTARS make the detection and plotting of these air defenses somewhat easier, but the actual task of taking the defenses out is still a nail biting activity. HARM missiles, once the scourge of the air defense operator, have been largely made ineffective by operating techniques (switching radar's off, or only switching them on for very short periods, additionally radar's can be operated in passive mode, using another transmitters' output to do its scans) and improvements to the repair side of the operation (radar antennas are relatively mass-less things, and older soviet designs only had metal and simple traveling wave tubes to damage). To counter this has been a growing emphasis on double strikes, the first disables the radar mast with a Shrike, HARM or similar. A follow-up operation then drops a real iron bomb on the target, the iron bomb has of recent been mainly laser guided, but we assume the use of GPS munitions will not be far off. This second strike can be timed to do most damage, not only to the radar installation, but to the repair crews too.

Airforces the world over have been trying to find ways to penetrate air defense systems with less bloodshed on the attacking side of the equation. Stealth was a major change in tactics, though even that technology has its limits, as was seen over Yugoslavia. The lose of highly skilled pilots is politically unsavoury to the US electorate, so means to limit the pilots' exposure, and prevent such loses, have been under way for many years.

Cruise Missiles

When the V1's first hit Britain in 1944, it was the first use of Cruise missiles. These missiles were fairly good at hitting targets in a known area, they reduced the aggressors exposure to danger and they were the right price. The Tomahawk and ALCM missiles are the latest versions of these versatile weapons. They can be made to go through the most dangerous air defenses while carrying a varied and substantial war load. Though the most recent versions were not really cheap, cheap, they were MUCH less expensive that stealth fighters. Of course a cruise missile is on a one way trip to destiny - there is no reuse - so their cost in comparison to traditional fighter bombers (used for multiple missions over 20 or 30 years) is slightly skewed.

Cruise missiles have been given some intelligence, not much, but some. They can be made capable of detecting attack and taking evasive action. They can be given targeting data right down to the moment of launch. They can even be given multiple targets, such that the first is bombed and the second is hit by the missile itself. These sorts of usage techniques and experience with reconnaissance drones during the Vietnam war, where drones were used in many roles including the carrying of weapons, has lead to the UCAV concepts we see today. However, there are differences.

One of the other influences in UCAV design has been that of the replacement of the pilot; during the 70's studies of such self-piloted, autonomous, vehicles were carried out. The studies showed that a self-piloted vehicle was going to be extremely complex, heavily dependant on computer power, and thus quite expensive. On top of which was the feeling that the thingsimply would not work - even a minor failure, one not anticipated by the designers or software architects might cause the vehicle to crash. But one thing that came through was that without a human on the vehicle, it could be made to maneuver at much higher G's and hence possibly be able to evade most pursuers, possibly even anti- aircraft missiles.

By the mid 1990's it had become apparent that the Military thought they had enough computer power to handle the control issues. They felt that the materials technology was in place, and that cheaper stealth technology could be used to give the unmanned air vehicle a high probability of success. Again, studies of how such a vehicle could be controlled showed that autonomous control was still out of the question, there were too many variables to plan for, and the aircraft was not going to be cheap if they were all accounted for, so a pilot was put in the loop. To add value to the proposition of keeping a man-in-the-loop was the failed cruise missile attack on an Afghan terrorist stronghold: the targets had moved-on 2 days prior to the attack, this could have been averted, the weapons returned unused, undetected if the operator had visual confirmation of the targets condition.

UCAV Concepts

The US Air Force is not the only player in this field, the US Navy is heavily involved as are a number of European nations. The projection of power from a carrier is an important strategic need, and men being shot down while flying Navy fighters is no more acceptable than Air Force pilots being shot down. However, there was an initial feeling that the needs were vastly different. The Air Force had initially looked at the concept of an unmanned interceptor, the Navy just wanted a bomber. The Air Force had to back off its position as it bumped right into the major problem with remotely piloted vehicles: radio or satellite bandwidth. A fighter was going to need lots of bandwidth to send back its sensor information and any camera imagery that could be generated. A small fleet of such fighters would swamp all available communications resources.

The Air Force and the Navy have begun to look at similar concepts for UCAVs. As strike aircraft they will not need the vast communications resources, but they will still stress what is available, they will be able to be flown into airspace that is far too dangerous for a piloted vehicle, and lastly they will need to be aircraft that can be reused, not just some throw away cruise missile concept.

Bandwidth

The engineering technical issues of how to build the UCAV are relatively straight forward, its the computational issues that will play the decisive part. The new UCAV's now being shown, will be able to autonomously fly to a target area, take synthetic aperture radar imagery and transmit it back to a base station, have it interpreted, targets finalized and the strikes planned. This still requires significant communications bandwidth, and also will put a great deal of emphasis on loiter time and stealth capabilities. Can the UCAV's live up to the needs and the technical challenges?

Operating a UCAV on the other side of the globe is going to require extensive use of satellite communications. The available bandwidth in this medium is going to severely restrict operations, limiting the number of UCAV's that can be airborne at any time. At present most of the military communications bandwidth is consumed, used by the intelligence community just trying to do its job. It might be possible to compress some of this data, it might also be possible to cause pauses in such traffic to make way for UCAV operations, but without significant improvements in satellite and ground based communications systems UCAV's will remain a curious military toy.

Changes (10/17/2000)

Things are moving here in a hurry. Along with US interest in these devices is the news on at least 2 European ventures (UK, EADS). Also, there has been renewed interest in the concept of using UCAV's as reconnaissance craft, rather than combat craft - harking back to the Vietnam origins of the species.

Neither of these activities addresses the critical issue of communications with the vehicle. Both initiatives want long range, low human impact and operation in arenas that might be heavily jammed. Not expanding communications and not working out what to do with jammed or intercepted communications, will make operation of these vehicle problematic in the very environments they were designed to operate in. Though civilian communications bandwidth is increasing, it is worth noting that this is not particularly secure bandwidth, and not consistent across the globe, making its use by the military awkward, at the least.

More Changes (06/01/2001)

Global Hawk has flown on several long duration flights and shown that in the reconnaissance role, UAV's have a role to play. These flights have also illustrated the need for more payload in the system. The airforce will likely rue the day they cancelled the Dark Star project, with its much greater lift loads and stealthier body.

The airforce has armed and used a Predator UAV to destroy armored vehicles. These tests were seen as critical to show that a UAV could be used as a platform to observe from, then put in a position that it could strike at targets as they appeared. While the tests were limited (some 3 missiles were fired it seems), they seem to have gone off without a hitch.

The Airforce seems to be getting cold feet about the use of UCAV's. Quite why is unclear, but it may be that strategic thinking and budgets don't provide the means to develop or employ them.

GPS has been used to allow an aircraft to land on a Carrier, hands free, in an initial step towards giving the Navy the ability to land UAV's on carrier decks without requiring ground controllers. The Navy seems more intent on UCAV's than the airforce, possibly because they may be the first on the scene in any conflict and don't want to expend manpower on fully deployed air defense systems that have not been 'softened up'.

Experience (01/15/2002)

As a consequence of the 9/11 terrorist activities UAV's have been used extensively in Afghanistan. In the unarmed mode they have proved invaluable, in-fact they have been sorely missed when they have been shot down or crashed (at least 2 Predators and a Global Hawk have gone down). In the armed mode, the recently tested Predator has proved to be useful, though there are only a handful available.

If lessons are being learned, it is probably that more UAV's are needed, they are excellent platforms from which to do surveillance, however the sensor packages that are needed are going to require a drastic update. It seems that some Air Force operators have had trouble with the Predators standard Visual systems, while other Synthetic Aperture Radar sensors have proven to be excellent.

Price

The one thing I am not finding is discussion of the cost of these aircraft. Many of the vehicles are substantial devices, the latest demonstrated by the French as big as a conventional fighter. This makes the construction processes, the materials use, and systems infrastructure comparable to some of the cheaper fighters. This is not cheap-cheap, just less expensive that say an F/A-18 ($55-65M). These are going to be expensive aircraft to lose, both in monetary terms and tactical terms - if they become a significant part of our fighting forces.

Recently the Pentagon has been trying to reduce the price of Global Hawk. The stated cost is $15 million per plane, but that does not include sensors. Including the sensor suite, the cost could be as much $30 - 40 million. At these prices, lose rates must be low, reliability high, to justify the fleet.

Some UCAV Links

Terms

UCAV	Unmanned Combat Air Vehicle. A man-less plane that may be semi-autonomous capable of carrying and launching weapons and acting to gather its own reconnaissance.
UCAV	Uninhabited Combat Air Vehicle. I believe this form (semantic in nature) is intended to indicate that while the plane is unmanned it is still operated by a remote pilot, there are less autonomous features.
UAV	Unmanned Air Vehicle. This is the type of small craft that has been available the last 20 years. It mounts a camera or surveillance sensor and is remotely piloted.
UCAR	Unmanned Combat Air Rotary. Helicopter form of a UCAV.