Our old Kingston colleague, Lambert Dopping Hepenstal, FREng, addressed the Association on October 11th on the topic of unmanned aircraft. Chairman Chris Roberts introduced the speaker saying that after gaining a degree in electronics and electrical engineering at the University of Surrey in 1972 Lambert joined the Avionics Department at HSA Kingston working on the Hawk and Harrier GR5. In 1985, together with John Farrow and Mick Mansell, Lambert was moved to Warton where he managed the systems Development of the Tornado and Typhoon, ran the BAe Military Aircraft research programme and was involved in the development of the Joint Strike Fighter. He was appointed BAE Systems Corporate Technology Director, Engineering Director for military aviation, programme director for the ASTREA (Autonomous Systems Technology Related Evaluation and Assessment) unmanned air vehicle programme and in 2013 retired as BAE Systems Engineering Director, Systems and Strategy.
Lambert said that the UK pioneered the field of pilotless
aircraft with the Tiger Moth-derived DH Queen Bee of 1935. Some 380 of
these anti-aircraft target machines were built. In 1952 the UK and
Australia collaborated on the long serving jet propelled Jindivik
Terminology has varied. The CAA (Civil Aviation Authority) used ‘unmanned aircraft systems’, the MoD (Ministry of Defence) used ‘remotely piloted aircraft systems’, and the popular press used ‘drones’. Industry didn’t like that but it was adopted by the IATA and is now in general use.
Military drones have been around for 10 - 15 years and now range in size from the Army’s tiny 10 x 2.5 cm Black Hornet miniature helicopter and 6m wingspan Watchkeeper to the 20m wingspan RAF Reaper. Military drones operate in segregated air space free of any civil population or in war zones. Operating civil drones presents a bigger challenge as they must operate in all air space. Originally envisaged as unmanned aircraft the development of small inexpensive drones, resulting from the rapid advances in battery and motor technology and miniaturised sensors and computers, was not anticipated. These small drones, typically weighing 4 - 5 kg, have proliferated there being some 1 million operating the US today with 5 million predicted for 2021. This disruptive technology has been a game changer in aviation. In the UK they started out being used for TV and film work but now have a large number of surveillance applications including those by estate agents and construction companies, as well as recreational use by the general public.
What is the attraction of drones? Removing the pilot from the aircraft means he can’t be killed or injured in a crash, endurance is increased as it is not limited by life support systems caoacity, flexibility of design as there are no shape constraints due to a pilot, and his systems do not have to be housed so, for instance, better aerodynamics can be achieved through increased slenderness. Drones can operate in environments which would be dangerous for a pilot such as fire fighting, nuclear accident investigation, oil refinery flare stack inspection, volcano and ash cloud investigation, maritime search missions in any weather conditions, long term search thanks to long endurance, very high altitude pseudo-satellite tasks, and crop spraying which is a high risk occupation for the pilot. Air-to-air refuelling of airliners by drone is being considered as this would allow the airliner to take off at low weight thus reducing air pollution. Parcel delivery is under study by Amazon as is aircraft external inspection, eliminating the need for staging, by easyJet. Agricultural crop surveys allow accurate fertiliser application. In fact new uses are being proposed all the time.
Some degree of autonomy is needed but this brings challenges of safety, ethics, regulation, insurance, legal responsibility and public perception, the latter being coloured by the ‘killer drone’ phrase used by tabloid newspapers. In other fields autonomy has been accepted. The Docklands Light Railway has been operating driverless for 30 years, and in modern ‘tube’ trains the driver only operates the doors. Rolls-Royce is proposing autonomous maritime freighters and driverless cars are a Press obsession. The speaker’s opinion was that these are “a long way off” because of the numerous difficulties; in comparison autonomous aircraft are “a doddle”!
Autonomous aircraft must integrate with manned aircraft; they can’t be segregated so they must appear to ATC (Air Traffic Control) to be like manned aircraft (transparency) so must follow the same rules (equivalence).They must be no less safe than manned vehicles. The public expectation is for driverless cars to be 100% safe even though driven cars are not. Ultimately the driverless car will be safer than the driven one. The same expectation will apply in the air; the first crash will get a huge reaction.
The basics requirements of autonomy are: to sense the environment, to calculate around that so decisions can be made and then actuate steering and speed control. Connection to the infrastructure via a secure communications system is essential. Decision making must be autonomous without the ‘pilot’ on board. There will be propulsion and electrical issues and new sensors will be needed. Very good guidance, navigation, collision avoidance and air traffic management are needed.
Legislation and policy changes will be needed to cater for safety, certification and qualifications of the ‘pilot’ supervisor on the ground. Communications radio frequencies are allocated to users every four years by the World Radio Conference. There is no spare space in the spectrum so frequencies will have to be bought from existing users.
All current regulations are framed round pilots who can see, hear, smell and feel - and he is not there; so new regulations are needed. The UK was at the leading edge in this field when in 2001 the CAA produced document giving guidance for the regulation of unmanned aircraft which has been adopted in principle world-wide and the IATA (International Air Transport Association), FAA (Federal Aviation Agency) and the ICAO (International Civil Aviation Authority) all have working groups. The ICAO provides the international view which is passed on to regions and in Europe this is the IATA who then pass their view to the nations, the CAA in the UK case. This applies only to state bodies such as the police and military and only for drones of 150 kg or less.
The IATA envisage three categories: open (low risk) with a minimum set of operational rules enforced by the police; specific operation (medium risk) authorised by the national aviation authority; and certified (higher risk), comparable to manned aviation, licensed by the national aviation authority who will approve maintenance, operations and air traffic management.
Having covered the philosophy of drones Lambert then described the ASTREA programme which started in 2006, before the explosion of small drone numbers so was aimed at reasonably large aircraft. The programme, which Lambert managed, was a £10m industry and government funded joint industry (including BAE Systems, EADS, QinetiQ, Rolls-Royce, Thales, Cobham) and university (including Cranfield, Loughborough, Aberystwyth) programme. The objective was to examine the whole unmanned autonomous operational concept and utilised synthetic environments, simulation, rigs and a flying test bed with two safety pilots on board which flew several missions in UK air space without any human intervention. The aircraft used was Jetstream 31 G-BWWW, Dunsfold’s old communications aircraft, modified to fly as an unmanned aerial vehicle.
BAE Systems’ experience in military drones started simply in 2000 with the Soarer hand-launched glider which was the first flight test of autonomous controls. Then, with Cranfield, came the Kestrel, and in the 2004 the modular jet powered Raven or Corax of 19 ft span. The HERTi in several versions based on a Polish sports glider fitted initially with a BMW motor cycle engine but later replaced with a Rotax light aircraft piston engine, was flown in Australia as the CAA would not allow it to fly in the UK. The large Mantis UCAV (unmanned combat air vehicle) twin R-R Model 250 turboprop powered aircraft, larger than a Jetstream, also flew in Australia. The Taranis of 2012, an Adour powered Hawk sized UCAV, has demonstrated fully autonomous operation from taxi through take-off, flight, and landing to parking. The Ampersand was an autonomous autogiro based on the RotorSport UK MT-03, and the Demon of 2010 had Coanda effect controls.
Finally, looking to the future Lambert saw “millions” of small drones doing multitudes of aerial tasks; autonomous technology allowing single pilot airline operations saving billions annually; light freight, postal and re-supply services; long haul freight using airship platforms; city air taxis and flying cars. The latter have been unsuccessful in piloted form because of the ungainliness of carrying wings on the ground and running gear in the air. The Airbus Pop-Up project addresses this by adopting autonomous air and land modules which are brought together only when needed. In the military arena Lambert predicted more combat drones including the current Anglo-French BAES-Dassault feasibility study, heavy lift airships, air-to-air refuelling, pseudo satellites and hypersonic drones.
The vote of thanks for this outstanding talk was given by Martin Pennell.