PAUL LEWIS / WASHINGTON DC & GUY NORRIS / LOS ANGELES

UAVs came of age in Afghanistan and are no longer regarded as decorative trinkets - commanders are beginning to see them as indispensable weapons of war

Unmanned air vehicles (UAV) have been a battlefield asset for 20 years, ever since Israel deployed the tiny Scout over the missile-infested Bekaa Valley in Lebanon - and arguably longer if drones employed during the Vietnam War are included. With each successive conflict, the role of UAVs has evolved, from naval gunfire support during the 1991 Gulf War to real-time satellite relay of video over Kosovo in 1999. Afghanistan marked the formal debut of armed UAVs and has given warfighters a sneak preview of what tomorrow's dedicated unmanned combat air vehicles (UCAV) and armed rotorcraft (UCAR) promise to offer.

Lt Col Douglas Boone, deputy chief reconnaissance systems division, USAF Directorate of Information Dominance, says: "If you looked at UAVs back in Bosnia and Kosovo, a lot of operators felt they were neat little trinkets. I think what they've found now is that UAVs are an integral part of air warfare - they have air tasking orders and commanders are asking: 'Where are my Predators?' They are no longer looking at them as some kind of science project - they're saying these are valid weapons of war."

The operational success in Afghanistan of the General Atomics RQ-1B Predator and the larger Northrop Grumman RQ-4A Global Hawk is proving an invaluable learning experience, lessons from which are already being fed back into these new systems, thanks to a spiral acquisition process designed to fast-track new capabilities into frontline service. The conflict is being closely studied by the US Department of Defense (DoD) as it formulates longer-term plans for developing and fielding the US Air Force's planned UCAV-AF by 2008, and the US Navy's UCAV-N and US Army's UCAR, both by 2015.

In the immediate aftermath of the 11 September attacks, Predator, along with its smaller Central Intelligence Agency cousin the Gnat 750, was the first intelligence, reconnaissance and surveillance platform on station in Central Asia as part of Operation Enduring Freedom.

In addition to directing "hundreds of strikes" against al-Qaeda and Taliban forces for a range of USAF and USN aircraft, the laser designator-equipped Predator also fired an undisclosed number of laser-guided Lockheed Martin AGM-114 Hellfire missiles against surface targets, data on which is still classified.

The decision to equip Predator with a designator was an outcome of the Kosovo conflict, where manned aircraft arriving over an area were unable to find targets detected by the UAV only minutes before. In 2001, there followed a series of experimental Hellfire firings from Predator to determine whether the slight lag in satellite communications between the controlling ground station and UAV would affect its ability to keep a laser locked on a target and hit it with Hellfire. Of the 16 missiles launched, 12 were direct hits and three very near misses.

"What we started to figure out in the early days of this war was that the nearest fast mover might be 20min out, and it would be nice to have this Predator capability. We had enough data from last summer to do it," says Boone. The next logical step in developing Predator had been a planned software modification by Raytheon to give the UAV a moving-target capability, but this follow-on phase of testing was overtaken by the war and has not officially been rescheduled.

The decision to acquire the larger, more capable MQ-9A Predator B comes as a direct consequence of the Afghanistan conflict. The vehicle has been designed from the outset to be armed and can carry up to eight Hellfire missiles, compared with two on the RQ-1B. The new UAV, however, is intended to operate at an altitude of around 45,000ft (13,700m), for which Hellfire is not ideal. Before being installed on RQ-1B, the US Army had never fired the missile above 2,000ft.

Weapons evaluation

The USAF is still evaluating sensors and armament for MQ-9A, but there are already a number of candidate weapons, including the Lockheed Martin Low Cost Autonomous Attack System, the 227kg (500lb) variant of the Boeing GPS satellite-guided Joint Direct Attack Munition and planned 113kg Small Diameter Bomb. With a gross take-off weight of around 4,545kg, the aircraft can carry up to 340kg internally and up to 1,360kg of external stores on six hardpoints.

When it comes to choosing which and how many weapons to install on a UAV, several issues are raised, including the need to balance this with other mission requirements and to ensure affordability. Predator B's principal role will remain that of a loitering reconnaissance platform positioned between the lower-flying RQ-1B and higher-altitude RQ-4A. The emphasis is therefore on lightweight weapons with which to target and destroy time-critical targets of opportunity.

In the case of Global Hawk, the decision has been taken not to arm it. Although the UAV can carry a 900kg payload, increasing to 1,360kg with the version due to be delivered in 2004-05, there are few weapons that Global Hawk could effectively employ at its 65,000ft-plus operating altitude. Furthermore, adds the USAF, as a benign system like the earlier LockheedU-2, it will enjoy easier access to overseas bases and airspace. What Global Hawk has demonstrated in more than 1,000h of operations over Afghanistan is the value of persistence.

"The ability to have a UAV parked over a bad guy and leave it there and never give him a break is a very powerful tool. Persistence is critically important and the Office of the Secretary of Defence's vision is to extend this capability. We're looking at technology to increase the endurance of current UAVs and at options that could provide us with an even longer-endurance UAV," says Dyke Weatherington, DoD deputy UAV planning task force.

This includes the use of more efficient JP4/8-based heavy-fuel engines, which would have the benefit of simplifying logistical support, reducing airframe and system weight, and combining UAV motherships with smaller vehicles, such as the recent Predator/Finder test.

Future concepts

Longer-term attention is focused on the USAF Research Laboratory's Sensor Craft concept and NASA Helios solar-powered flying wing. The latter is payload restricted, but a better potential application of the propeller-driven vehicle could be as a communications relay node.

When it comes to arming UAVs, the planned Boeing UCAV-AF will be the air force's weapon of choice. In the light of Afghanistan and the success of Predator, the decision was taken earlier this year to accelerate the programme and begin fielding an operational system by 2008. It is now not a question of whether the current USAF/Defence Advanced Research Projects Agency (DARPA) programme can meet this schedule, but whether it can do the job. "The issue is: can the X-45B demonstrate the level of autonomy necessary to do the mission and is it the right size platform?" says Weatherington.

The planned X-45B, compared to the X-45A now flying, has already grown in wing span from 10.3m to 14.3m to get the demonstrator closer to the proposed A-45 operational vehicle's goal of carrying a 1,635kg weapon load to 1,200km (650nm). It could grow more as UCAV evolves from the initial Block 10 suppression of enemy air defence role and new weapons are added, including a planned Block 30 directed-energy capability. The concern is that there will be an exponential growth in the price of the UCAF-AF, originally pitched at one-third the cost of the Joint Strike Fighter.

Survivability

Even at a conservative estimate of $12-15 million a copy, UCAV-AF will cost three to four times more than today's Predator, and at that price the air force can no longer afford to continue losing UAVs at the rate of 100 per manned aircraft crash. Enhanced system reliability and survivability will therefore be a critical requirement for both UCAV-AF and UCAV-N, driving up costs further. The USN's requirement for UCAV-N is perhaps even more challenging in that it is asking for a single-engined, 12h-endurance vehicle, capable of operating initially in a reconnaissance and ultimately in an armed-strike role.

The US Army is facing similar challenges as it embarks on a joint effort with DARPA to demonstrate the UCAR. "There are a lot of questions that need answering," says Col Waldo Carmona, US Army Applied Aviation Aviation Technology Directorate (AATD) commander. "What will be the right balance between situational awareness, survivability and the cost of making UCAR survivable? We can't wait until UCAR is flying for answers, they need responses by 2006."

The AATD is planning experiments on a series of past and present vertical take-off and fixed-wing UAV testbeds at its Fort Eustis facility to help it find some UCAR solutions, as well as assess the UAV needs of the army's Future Combat System. They will include the Frontier Systems A160 Hummingbird, the Sikorsky shrouded- rotor Cypher II and the SAIC Vigilante, while AATD is negotiating with Northrop Grumman to test the US Navy's stalledRQ-8A Firescout as well as Bell's Eagle Eye tiltrotor. It is also converting two Bell AH-1s into armed UAVs for weapons testing.

The focus of army testing will include optimising UAV missions and weapon packages, teaming of manned and unmanned platforms, and battlespace management. The US Army has an effort under way to arm some existing UAVs, including equipping its TRW/Israel Aircraft Industries (IAI) Hunter with the Northrop Grumman Brilliant Anti-Tank munition and/or the General Dynamics/ IAI Lahat laser-homing anti-tank weapon.

Video feeds

One issue that has been raised by the army during the recent conflict has been its inability to take direct video-feed from Predator, with data instead having to be routed back via command and control centres, resulting in delay. "Guys flying the UAVs are not able to pass data directly to people in the forward area," says Carmona. "What the army and all the services have learned is that we need to get the data to the warfighter as soon as possible."

One suggestion has been to pass control of UAVs from a regional centre to a forward area for local tasking and hand it back once completed. For vehicles such as Predator, which require a sophisticated ground-control centre, this is likely to prove impractical. The answer lies perhaps in better development of a joint concept of operations, ensuring that a common set of technical standards is in place to allow different services to interface with one another and other UAV systems. This will also allow quick and reliable access to still pictures, video and signals intelligence.

"All UAVs today have a unique propriety method for their ground system control and formatting and fielding of data. If someone else wants the capability to even know where a UAV is, let alone run it, they're going to have to buy vendor A's software and embed it. If we can develop a single air-vehicle interface, then I don't care what's behind that interface at the vehicle level, so long as we get away from the stove-pipe architecture we have today," says Weatherington.

Source: Flight International