Replacing AWACs With UAVs?

10/27/2011  Neil Waghorn - defenceiq.com

As you’ve probably read before on Defence IQ, the use of unmanned aerial vehicles (UAVs) has exploded over the last decade and, according to the 2011 US Aircraft Procurement Plan, the number of platform types is set to almost double by 2021. These platforms have evolved from being additional pieces of equipment to an essential tool in today’s military operations, and in keeping with this evolution, the mission capabilities of these machines have gradually expanded.

The Predator, for example, has evolved from being a surveillance vehicle, to gaining a laser targeting ability, before finally having an offensive capability in the form of Hellfire missiles. With the advance of the UAV role, especially within the surveillance field, it is worth assessing the potential impact of unmanned platforms on airborne early warning and control (AEW&C) capabilities.

Among the most easily recognisable aircraft in the world, due to its large rotating radar dome attached to the top of its airframe, the E-3 Sentry  has been the airborne warning and control system (AWACS) of choice for a variety of nations since 1977. Over the course of this long history, the E-3 has undergone multiple upgrades to ensure that it remains at the forefront of technical capabilities. As UAV technology progresses, however, the E-3 may not be able to keep up.

One proposed upgrade to the E-3 is the Mission Crew to Ground programme. This programme would transfer the control capabilities out of the E-3, and, according to the Federation of American Scientists, ‘allow more sensor growth in volume and weight on-board the E-3 for enhanced surveillance task’. It would also allow command and control to be centralised, allowing for the faster, more efficient sharing of information and control. The reduction of the crew of an E-3 from around 18 (mission dependent) down to ‘Communications Technician, Airborne Radar Technician, and the flight crew’ will significantly reduce the exposure of highly trained servicemen to potential danger. This removal of command capability will convert the E-3 into a solely AEW aircraft, such as the E-2 Hawkeye (albeit one with vastly increased range and variety of sensors).

If this programme were to progress, with the E-3s becoming sensor platforms, it would be necessary to weigh the advantages to the continued use of the E-3, as apposed to multiple smaller platforms such as UAVs or other manned aircraft.

The former USAF state secretary, Michael W. Wynne, raised several import questions about the survivability of large ISR assets such as AWACS aircraft in his article for ‘Second Line of Defence’. Wynne stresses that in a combat scenario against enemy aircraft, large assets ‘won’t last the first 10 minutes of the exchange’. Wynne argues that large assets should be replaced by smaller manned aircraft such as F-22s or 35s, commenting on the fiscal investment necessary to keep the larger aircraft in use. From his perspective, smaller, more survivable, multi-role aircraft would be a better investment of limited funds. There are several problem with using F-22s or 35s to perform AEW. One of which, is the large number of aircraft required to cover the area that an E-3 could monitor (an E-3 has a range in excess of 300nm). Fighter aircraft have a shorter fuel capacity than the 11 plus hours of an E-3 and would require inflight re-fuelling.

An alternative to Wynee’s suggestion of using F-22s would be the use of UAVs such as the Global Hawk. These unmanned platforms would allow the collection of ISR from assets with endurance that surpasses the E-3, (according to Northrop Grumman, the Global Hawk ‘can fly 1,200 miles to an area of interest and remain on station for 24 hours’). The use of UAVs would also, as mentioned, neutralise the risk to pilots. If fighter aircraft were used to replace E-3s then there would potentially be a number of pilots flying over enemy territory exposed to ground threats. UAVs could conduct these operations without endangering their lives.

The survivability of a UAV is arguably higher than an E-3, due to its relatively smaller radar profile (the E-3 is 46.6 meters long, as opposed to a 13.5 meter long Global Hawk) and higher ceiling (Global Hawk can fly at 65,000 feet, while the E-3 is 29,000 feet). As UAV technology advances, and the concept of Combat UAVs become a practical reality, it may be that a UAV ISR platform may be able to defend itself, increasing its survivability further still.

A US Congressional Budget Office paper, ‘Policy Options for Unmanned Aircraft Systems’, suggests that, although large AEW aircraft can ‘provide surveillance of large areas of sky or ground, their sensors have typically not been appropriate for the type of surveillance and targeting needed in counterinsurgency operations, which focus on individuals or small groups’.  Although a decade of insurgency in Afghanistan has made COIN highly topical, it is prudent to remember that conventional warfare still exists. UAVs may provide an option to provide ISR for COIN and conventional operations. Due to the relative low cost compared to large ISR aircraft it may be possible to assemble a variety of UAVs, configured to operate different mission types. Indeed, with the current focus on open architecture and the modular nature of equipment, this may be a practical way to retain a capability to cover both regular and irregular conflicts.

It has been proven that an E-3 could control multiple UAVs. Not long ago, an E-3 successfully took control of three ScanEagle UAVs. The control of UAVs from airborne vehicles has successfully been achieved by a variety of vehicles including the Apache helicopter and Tornado. If the E-3 retains its C2 capabilities, then the E-2 can potentially use UAVs to extend their range, covering a region that would have previously required several manned aircraft. While this reduction in number of aircraft will offer advantages such as exposing less crew to danger, the advantages do come with a large risk.

If the entire AEW scope is delegated from three AWACS platforms to a solitary manned aircraft and a host of UAVs, and the AWACS encounters difficulties which results in it not being operational – an electronic failure, enemy action or a catastrophic engine failure – then a wide area will be forced to rely on other early warning systems. If the UAVs are dependent on the AWACS, then the solitary AWACS platform aloft has become a critical node for the enemy to target. By having several AWACS aircraft in theatre, there is the capability to provide coverage if one aircraft is lost, albeit less efficiently.

As UAV technology rumbles forward, it may well be that UAVs eventually replace manned aircraft altogether. Science fact or science fiction, it is certain that UAVs will continue to be integrated into all levels of aerial operations, just as the rise of the unmanned machine continues to carve its domineering presence into all aspects of military service.