Crossing oceans is challenging, fascinating and satisfying. The westward voyage of the Christopher Columbus-led three-ship fleet from Europe in 1492 established the first link between America and Europe across the Atlantic Ocean. Since then, people on both these continents have been looking at faster and more efficient connectivity across the Atlantic. The advent of aviation allowed the use of the third dimension. In June 1919, Captain John Alcock and Lieutenant Arthur Whitten Brown made the first non-stop aerial crossing of the Atlantic in a modified Vimy IV. They flew from Lester’s Field, near St. Johns, Newfoundland to Clifden in Ireland in 16 hours and 27 minutes. From that modest beginning, 99 years later, now, over 2000 manned aircraft cross the North Atlantic daily.
The aviation industry has come a long way since the first flight by the Wright Brothers in 1903. It has expanded in both military and civil aviation with manned and unmanned aircraft. Later this year, while the Royal Air Force, one of the first military aviation wings, will be celebrating its centenary, the aviation industry will be looking at two other significant milestones. First, in the manned aircraft category in civil aviation, the world’s longest commercial flight will be launched in October by Singapore Airlines between New York and Singapore. An Airbus A350-900ULR (Ultra-Long-Range) will cover this distance of around 9,500 miles in 18 hours and 45 minutes. This will relegate to second place the existing longest route of Qatar Airways from Auckland to Doha of 9,032 miles in 18 hours by Boeing 777-200LR. In the unmanned category, with an Unmanned Aerial Vehicle (UAV) crossing the Atlantic, a new chapter is about to begin.
Unmanned Trans-Atlantic Foray
On July 10-11, 2018 General Atomics Aeronautical Systems plans to make the first-ever trans-Atlantic flight of a Medium-Altitude Long-Endurance (MALE) UAV.5 Technological advancement in computing and communication facilitated the development of UAVs. Controlled from a ground station, the UAVs either fly a pre-planned path or can be dynamically controlled. For the trans-Atlantic mission, an MQ-9B Sky Guardian is scheduled to fly from Grand Forks, North Dakota, USA, to the Royal Air Force (RAF) Base Fairford in Gloucestershire, UK, located over 3300 miles away.
The prime challenges faced by Captain John Alcock and Lieutenant Arthur Whitten Brown in their venture 99 years ago related to the endurance of man and machine, as well as reliability and navigation over the sea without any ground reference points. That mission was accomplished by using a modified aircraft to carry extra fuel to increase range. Despite multiple component failures and airframe icing en route, they managed to reach Europe and landed in Ireland. They navigated by using a sextant and taking reference from the position of the sun and moon whenever visible in cloudy and foggy weather. These will not be issues with the forthcoming MQ9B mission. The MQ9B has already set an endurance record of more than 48 hours of continuous flight. It being unmanned, the human endurance aspect is well taken care of with the Pilot in Command (PIC) sitting in a comfortable cabin at the Ground Control Station (GCS). A well-established Global Position System (GPS) provides accurate navigational reference points. The MQ-9B with a ceiling of a 40000 feet and speed of 210 knots, has improved structural fatigue and damage tolerance. With robust flight control software, it is capable of operations in adverse weather including icing conditions. This will obviate the weather-related challenges faced by the first trans-Atlantic flight in Vimy IV. Being unmanned, the problem of disorientation in foggy and cloudy Instrument Meteorological Conditions (IMC) faced by aircrew is also completely eliminated.
The main challenge for the mission will be retaining communication between the UAV and the GCS. Although most of the systems on board a UAV work in an automated mode, it is essential that the PIC continuously monitors the health of the UAV’s on-board systems. This is achieved by the UAV relaying various parameters to the GCS. The PIC, after assessing the situation, can alter the mission profile by transmitting the requisite instructions from the GCS to the UAV. Thus, two-way communication between the GCS and UAV allows for dynamic control of the UAV. As a safety feature, almost all UAVs are designed to head towards a designated recovery base following a pre-planned path in case of a communication failure.
The communication equipment on board the initial generation of UAVs had severe limitations in terms of antenna size and power. Therefore, the maximum effective range for controlled UAV operations was within a few kilometres of the GCS. But with better sensor technology and miniaturisation of components, operations became possible within the Line of Sight (LOS) range. It is possible to control the UAV directly from the GCS up to 200-300 km. With another UAV acting as a Radio Relay, the range could easily be extended beyond 400 km. In the mountains, terrain may disrupt the LOS leading to loss of communication between the GCS and UAV. Additionally, to retain LOS, UAVs are required to operate at medium to high altitude. But, at these altitudes with a very large area in direct LOS, intentional or accidental interference from other ground-based transmitters could disrupt the UAV operations.
To overcome the range related limitations, Satellite-Based Communication (SATCOM) for UAV control was conceptualised, tested and operationalised. This entailed that the two-way communication between the UAV and GCS takes place via a communication satellite. The limitation of LOS was overcome and restrictions of distance between the controlling GCS and the UAV made redundant. Another major advantage of using SATCOM was relative immunity of the UAV from ground-based intentional or accidental interference owing to the location of its antennas on the upper airframe.
But UAV SATCOM came with its own set of limitations. The large distances between the GCS, Satellite and UAV have increased the travel time of radio signals. This has made dynamic control of UAVs more difficult. The time lag restricted options during a reactive scenario in a fast-changing operational environment. Secondly, the relatively small bandwidth available for uplink and downlink for SATCOM between the GCS and UAV restricts the exploitation of the mission payload on board the UAV and its feedback (normally a video). Thirdly, only a very limited number of UAVs can be controlled within the footprint of the beam pattern of a given communication satellite. This is to ensure that the requisite bandwidth in a non-interfering radio frequency is available to UAVs for operations. Notwithstanding these limitations, SATCOM is a desirable component in medium/large UAVs for military applications. Even older UAVs are being retrofitted with SATCOM to exploit its advantages. For the trans-Atlantic flight, the MQ-9B’s ground control station will use Inmarsat’s Swift Broadband SATCOM to communicate and control the aircraft. The same system will be used in the UAV’s final configuration for capabilities such as automatic take-off and landing.
In the recent past, the focus of UAV technology has been on developing UAV Swarms with multiple very small UAVs coordinating with each other to optimise the task using artificial intelligence. Such technology, when fully developed and deployed, will provide a tactical solution to military commanders. It will allow the achievement of tactical objectives with minimal collateral damage. However, long-distance UAV flights with multiple sensors will continue to enhance their relevance by providing battle space overview to the military commander. Such long-range missions are best deployed for surveillance tasks, exploiting their low signature and long endurance. A vast area can be kept under periodic surveillance without moving the hardware associated with the GCS. This allows a high degree of flexibility in operations with requisite secrecy. Additionally, it permits sea surveillance without the need to deploy a ship based GCS. Such systems, when weaponised, provide an additional offensive capability for Time Sensitive Targeting (TST) at a very low operational cost. This aspect is best summed up by Defence Advance Research Project Agency (DARPA) programme manager Jean-Charles Ledé who, after a long endurance test of a UAV, said, “This record-breaking flight demonstrated the feasibility of designing a low-cost UAV able to take off from one side of a continent, fly to the other, perform its duties for a week, and come back – all on the same tank of fuel. This capability would help extend the footprint of small units by providing scalable, persistent UAV-based communications and ISR coverage without forward basing, thereby reducing personnel and operating costs.”
This long-range UAV operation capability is of immense value for countries like India with significant maritime interests. The Indian Navy, with its mission based deployment of ships and a small fleet of maritime surveillance aircraft, monitors activities in the country’s area of interest in the Indian Ocean. The addition of long-range surveillance UAVs will expand the area under surveillance. UAV missions could be seamlessly controlled by GCS located on the mainland or on Island territories or even on ships. Enhanced Maritime Domain Awareness (MDA) will not only assist the security apparatus but could also provide the requisite information to partner countries in the Indian Ocean Region (IOR). The faster speed of UAVs, as compared to surface vessels, allows quick relocation for surveillance in the area of a developing situation with respect to security or natural calamity. Surveillance of island territories or mountainous terrain could be carried out by the UAV without the need to relocate the GCS. To augment current UAV capability, India is looking at various options in terms of importing equipment on one hand and developing indigenous systems on the other. The quantity and quality of UAVs in India are set to increase. With increasing numbers, the demand for electromagnetic spectrum allocation and utilisation for UAV operation will increase. If not optimised, this could become a show stopper. While a lot of research and development effort is being devoted to platforms and on-board sensors, communication experts need to innovate so that simultaneous operations by a large number of UAVs could be conducted within the available bandwidth.
Military operations are undertaken with restrictions imposed on the use of the airspace by other operators. Under this controlled environment, UAVs have carved out a niche for themselves. Therefore, the strength of UAVs in armed forces across the world is growing at a very fast pace. For non-military purposes, their use is restricted to very small predefined spaces for a short duration with prior clearance in most parts of the world. For greater utilisation over long range, UAVs still have a long way to go. In the absence of a human on board, they need to be equipped with collision avoidance systems. Besides, they have to be certified for airworthiness in all classes of civil airspace. Developments in the field of Artificial Intelligence will play a major role in this regard. Once the requisite certification is achieved for non-segregated civil airspace operations, UAVs will outnumber manned aircraft in the world. The planned trans-Atlantic flight in July 2018 by MQ9B is a first major step in that direction.
1.New York Times, June 16, 1919, available at http://www.aviation-history.com/airmen/alcock.htm, accessed on June 27, 2018.
2. ICAO NAT EFFG, North Atlantic FIR Traffic Forecast, 2017, available at https://www.icao.int/EURNAT/EUR%20and%20NAT%20Documents/NAT%20Economics%20and%20Forecast/NAT%20FIR%20Traffic%20Forecast-2017-04-26.pdf, accessed on June 28, 2018.
3. “World’s longest flight to be launched by Singapore Airlines,” The Guardian, May 30, 2018, available at https://www.theguardian.com/world/2018/may/30/worlds-longest-flight-to-be-launched-by-singapore-airlines, accessed on June 27, 2018.
4. Eric Rosen, “The 10 Longest Flights in the World by Distance,” Forbes Travel, March 26, 2018, available at https://www.forbes.com/sites/ericrosen/2018/03/26/the-10-longest-flights-in-the-world-by-distance/#7e1c2ad348a1, accessed on Jun 27, 2018.
5. General Atomics Aeronautical, Press Release, “GA-ASI To Fly First Trans-Atlantic Flight of a MALE RPA,” June 25, 2018, available at http://www.ga-asi.com/ga-asi-to-fly-first-trans-atlantic-flight-of-a-male-rpa, accessed on June 28, 2018.
6. Kishore Kumar Khera, “Has the Time Come to Replace Manned Combat Aircraft With Armed Unmanned Aerial Vehicles?” IDSA Comment, August 16, 2017, available at https://idsa.in/idsacomments/replace-manned-combat-aircraft-with-armed-unmanned-aerial-vehicles_kkkhera_160817, accessed on June 28, 2018.
7. Note 5.
8. Report on Capt. John Alcock and Lt. Arthur Whitten Brown, Aviation History Online Museum, available at http://www.aviation-history.com/airmen/alcock.htm, accessed on June 28, 2018.
9. Note 5.
10. The specifications of MQ9B RPA are available at http://www.ga-asi.com/mq-9b, accessed on June 28, 2018.
11. Note 5.
12. Darren Quick, “Jet fuel-powered UAV completes record 56-hour flight, with plenty left in the tank,” New Atlas, January 9, 2017, available at https://newatlas.com/vanilla-aircraft-va001-uav-endurance-record/47295/, accessed on June 28, 2018.
13. “India fastest growing market for unmanned aerial vehicles,” The Economic Times, March 26, 2018, available at https://economictimes.indiatimes.com/news/defence/india-fastest-growing-market-for-unmanned-aerial-vehicles/articleshow/63466658.cms, accessed on June 29, 2018.
14. Note 6.