By Dr Peter Layton
Editorial Note: In the second part of a two-part article, Dr Peter Layton explores the evolution of the armed unmanned aircraft from its first use in the Second World War through to the First Gulf War. The first part of this article can be found here.
In retrospect, during the Cold War, the dice were stacked against armed unmanned aircraft. Improving aircrew survivability in a major war – the primary requirement – involved operating in a very hostile, sophisticated air environment in the presence of extensive jamming that could defeat the data links necessary to control unmanned aircraft. Furthermore, the computers, aircraft systems and onboard sensors needed to make such an aircraft work were all big, cumbersome, unreliable and costly. Even when cost was not an issue as in the case of Advanced Airborne Reconnaissance System project of the late Cold War, the unmanned aircraft designs ended up being very large, technically challenging, of doubtful effectiveness and somewhat inflexible in operation.
In the 1990s the stars radically realigned to favour armed unmanned aircraft. In the early 1990s, armed violence erupted in Yugoslavia. The conflict was slow paced with a need for protracted surveillance rather than episodic reconnaissance, but none of the existing systems seemed quite right. Manned aircraft lacked persistence while satellites had predictable orbits and known overhead times, could not easily be repositioned to survey new areas and were impacted by bad weather. Meeting the new requirements driven by the wars in the Balkans was however eased somewhat by the air environment now being permissive with little threat from air defences. In the winter of 1992, the US Joint Staffs and the Office of the Secretary of Defense initiated a quick reaction program for a long-endurance unmanned aircraft. First flight came within six months of contract award, and a year later the General Atomics Predator unmanned aircraft was in operations over Bosnia.
Seemingly quick, the Predator’s rapid entry into service exploited some 15 years of DARPA experiments, trials, partial successes and utter failures. The overall airframe design was point-optimised for the particular mission with a slender fuselage with pusher configuration, long sailplane-like wings, inverted V-tails and a ventral rudder. The engine was a horizontally-opposed, liquid-cooled, four-stroke, geared piston engine with a minimal frontal area that offered high power at a moderate rpm, very low fuel consumption and very low vibration. The Vietnam-era unmanned jet aircraft saved weight by not being fitted with an undercarriage but were difficult to launch and recover. Predator’s used a tall, lightweight fixed undercarriage that gave considerable ground clearance. This design meant that the Predator had a maximum speed of only some 120kts, but they could loiter for almost a day flying at 70kts at an altitude of 12-15,000 ft. This performance was adequate – if not sparkling – for the new requirement for long persistence albeit useless for the earlier Cold War type missions where survivability was critical.
In design terms, the airframe and engine were skillful but somewhat primitive having more in common with the 1944 TDR-1 unmanned aircraft (see Part One here) than a 1990s military aircraft. The real innovations that addressed the big technological challenge – how to fly and operate an unmanned aircraft in combat for 24 hours or more without on-board humans – lay in the electronics. Computer advances now allowed dramatic increases in computing power, speed and reliability while communication advances connected the Predator literally to the world, changing everything.
Controllability was addressed using a purpose-built flight control computer more powerful than that used in the F-16 fighters of the time. This made the Predator stable in flight in all weathers and easy to control remotely especially during the problematic take-off and landing phases. Navigation was addressed using the satellite-based Global Positioning System (GPS). Earlier unmanned aircraft had significant navigation problems with Vietnam era aircraft often missing their planned target by some 10-12 kilometres. GPS was a real breakthrough that provided an off-board, ubiquitous, highly accurate navigation method. However, it was new communications technology that made armed unmanned aircraft practical.
Over its first few years of operational service, the Predator system took advantage of and was integrated into, the rapidly advancing online world. It broke away from being dependent on line of sight control with the fitment of high bandwidth satellite communication data links. This has made the armed unmanned aircraft both remarkably flexible and remarkably useful.
Remote Split Operations endowed remarkable flexibility. A small team at a forward airbase launched a Predator using a line-of-sight wireless link and then transferred control to operators located anywhere globally who used satellite communications links. These remote operators then flew the long-duration operational part of each sortie, changing crews throughout the mission as necessary. After the mission, the Predator was handed back to the small forward deployed team which landed the aircraft and turned it around for the next mission. This way of operating meant the forward team was small, requiring only very limited support and minimising the people and equipment needed to be deployed.
The second aspect – that of being remarkably useful – was made possible using modern communications technology that allowed data from the unmanned aircraft to be sent worldwide in near-real-time.
By the late 1990s, sensor technology had considerably advanced allowing relatively small high-quality daylight and night television systems to be made for an affordable cost. Moreover, these, when combined with a laser rangefinder and the onboard GPS navigation system, allowed an unmanned aircraft to now very accurately determine the location of the object being looked at. Such pictures and the position data though were of limited use if access to them had to wait for the aircraft’s return to base. Now with high-bandwidth satellite communication systems, full-motion video tagged with its accurate location could be sent to distant locations. Multiple users worldwide could access real-time imagery of events as they occurred.
The impact of this was that not just the aircrew controllers could see the video and make use of it. Now local land, sea and air commanders could have instant access to the imagery allowing more active command and control of assigned forces. High-level commanders and government ministers at home could also gain an appreciation of the tactical events unfolding. These live feeds from the world’s battlefield were compelling viewing; the term ‘Predator Porn’ was coined – you cannot take your eyes off it.
As importantly, imagery analysts and other exploitation specialists at locations worldwide could now bring their expert skills to bear to provide instantaneous advice on niche aspects to the complete command chain, including the operators controlling the Predator. The satellite communications links allowed many skilled people to be ‘onboard’ the unmanned aircraft flying in some distant theatre of operations, making its operations much more useful than a manned aircraft traditionally could be.
The final technological piece in the armed unmanned aircraft jigsaw came together with the fitment of air-to-ground weapons. On operations in the Balkans in the 1990s, Predator’s provided imagery that was used to cue manned aircraft to essential targets, so they could deliver weapons on them. This worked well but sometimes the manned aircraft were not readily available and hours might elapse before they were overhead. This delay meant that hostile forces could group and attack civilians or friendly forces before defensive measures could be taken. To overcome this, lightweight, small-warhead Hellfire missiles were fitted to the Predators that could be fired by the remote aircrew controllers against time-urgent targets. The range of weapons that could be fitted greatly expanded in later Predator developments but the fundamental constraint of needing to be lightweight to allow the unmanned aircraft to fly long-duration missions remained. Manned aircraft were still necessary for the battlefield situations and targets that required large warhead weapons.
In the early part of the 21st Century, armed unmanned aircraft finally came of age. This occurred with the coming together of several factors. Firstly, in the operational circumstances of the time, the air environment was much less hostile allowing simple aircraft to survive and potentially undertake meaningful roles. Secondly, there was now a pressing operational need for persistent surveillance; a task manned aircraft were unable to meet. Thirdly, aircraft technology has sufficiently mature to allow an unmanned aircraft to be controllable, navigate successfully, carry suitable sensors and incorporate satellite communications equipment. Lastly, in the internet age, once a video stream was received anywhere, it could be sent worldwide to allow anybody with an authorised computer terminal to access and use it.
After more than half-century of development, the aircraft was the easy bit. It was the electronics onboard and overboard, the ground controlling equipment, the complex support base and the large numbers of skilled staff involved at every level that made the whole operation work. It was not surprising then that defence forces pivoted to talk less of unmanned aircraft and towards terminology such as Unmanned Air Systems. Predators and their ilk were a system of systems, mostly ground-based but with one element that flew.
Dr Peter Layton is a Visiting Fellow at the Griffith Asia Institute, Griffith University. His PhD is in grand strategy, and he has taught on this at the US National Defense University. He is the author of the book Grand Strategy.
Header Image: An MQ-1 Predator, armed with AGM-114 Hellfire missiles, on a combat mission over southern Afghanistan, c. 2008. (Source: Wikimedia)