| Unmanned Cargo Aircraft; from anywhere to everywhere
It is a great pleasure to write this editorial, because of the reason why I got this opportunity: the start of a regular feature about Unmanned Cargo Aircraft (UCA) in Aircargopedia. The timing is appropriate. The first urban delivery drones are in operation by Aha in Iceland, and Astral Aviation in Kenya is preparing the first service with large UCA next year. It is good that there now is a publication that informs its readers about the fast-moving world of UCA. In this editorial I will first go into the potential of, and challenges for, UCA, and then address some specific issues that Mr. Ghosh asked me to: the possibilities of converting current manned aircraft and Unmanned Aerial Vehicles (UAVs) into UCA, the consequences for the job security of pilots of manned aircraft, and the 'Tunnel in the Sky' concept for integrating UCA in controlled airspace.
Before proceeding, I should mention that there are basically two types of UCA: small 'drones' like those being developed by Amazon and utilized by Aha for delivering small packages (from books to pizzas) over short distances in a mostly urban environment, and large, longer range UCA that can fly, for example, between China and the United States with loads of a few hundred pounds up to 10 tons or more. The latter is where my expertise lies. I will not further discuss urban delivery drones.
The Potential of UCA
The most important advantages and limitations of unmanned cargo aircraft versus other means of transport concern cost and productivity. The most obvious cost advantage is the saving in crew costs. A UCA needs a 'pilot', henceforth called a controller, but this person does not fly the UCA directly; he or she gives general commands concerning course, altitude etc and hence can monitor multiple UCA simultaneously. Since crew numbers for cargo aircraft are largely independent of size, it follows that cost savings are proportionally the largest with small aircraft.
A second advantage is that no pressurized cabin is needed. Even if some cargo does need pressurization, this may well be catered for by small specialized containers, and in any case a complicated and maintenance-intensive air-conditioning system can be eliminated. A further advantage also has to do with the construction of the UCA. The ideal shape of an aircraft from a fuel efficiency point of view is a flying wing - just a wing with no weight- and drag-inducing fuselage or tail.
However, a wing is not deep enough to accommodate passengers or crew, unless it is made very big and heavy. Since most cargo can be transported in relatively small containers, a flying wing with just a small thick section in the middle can in theory be an excellent UCA. Such a 'blended wing body' ideally uses up to a quarter less fuel than a conventional 'tube and wing' aircraft.
There is another advantage of UCA over manned aircraft that pertains to fuel efficiency. The controllers of the UCA on the ground can be relieved whenever necessary, so there are no crew-related limits to the duration of a flight. This makes it possible to choose a cruising speed that is optimized for striking the optimal balance between cost and speed of cargo delivery. A lower speed means less fuel cost. Also, flying at a lower speed than, for example, a Boeing 777 cargo aircraft, means that, instead of a turbofan engine, a turboprop engine can be used, which consumes less fuel than a jet engine for the same thrust.
One can think of further cost advantages of UCA, but the ones mentioned above are the most important.
As far as can be judged at present, the biggest advantage of UCA in terms of productivity is the fact that no crew scheduling is needed. No crews and UCA need to be brought together for a flight, and, perhaps more importantly, UCA can be assigned to unscheduled flights at a moment's notice without positioning a crew for subsequent flights. A typical problem with air cargo is that cargo streams between locations are sometimes asymmetric: more cargo is flown from A to B than from B to A. It may be possible to fly from a home base to a number of other destinations and from there back to the home base, optimizing loadfactors.
Of the many challenges that UCA face, I will pick two: lack of insight in the market and ensuring safety
Since there are no operational UCA yet, the claim of any manufacturer that 'his' UCA is what the market wants has yet to be proven. Producers of UCA have no way of knowing whether their aircraft will be a success. That is of course the case with every new product, but UCA suppliers have no similar products already on the market that could provide clues. Small companies often do not have the resources to survive a failure and thus are reluctant to commit to development of hardware without at least some orders. Potential clients, on the other hand, want to see UCA in operation or at least in test before buying them. At present, we know of two organizations, both members of the Platform Unmanned Cargo Aircraft, contemplating or planning regular UCA operations. But the introduction of UCA will be slow.
Potentially, unmanned aircraft very likely can be as safe, or safer, than manned ones. However, there are three challenges that have so far been identified.
The first challenge is that the safety of UCA, and of UAVs in general, that are now in large-scale use is not representative of the safety that is required or can be obtained. Many present-day UAVs are cheap and expendable; the level of redundancy required of manned aircraft is simply not cost-effective. Yet, if UCA are to be flown above populated areas with no more restrictions than manned aircraft, they will have to have an equivalent level of safety.
Even when safety requirements are clear in theory, the danger exists that, in large-scale UCA operations, safety hazards surface that have not been, and probably could not have been, foreseen without knowledge about the way the use of UCA develops over time.
The last challenge to be mentioned here is that aviation is so safe that even if and when UCA become as safe as manned aircraft it will take many years to accumulate enough statistical data to prove the point.
Modification of presently available aircraft
From the above, we can conclude that the competitive advantage of UCA is greatest on relatively 'thin' routes, and that the absence of a cockpit crew means much more than a reduction in salary cost. What does this mean for the possibility of converting presently available manned or unmanned aircraft into UCA?
Conversion of large planes like Boeing 747s or Airbus A330s has, in my opinion, limited utility. Salary cost are a relatively small proportion of total cost for such aircraft, and the large payload, long runways needed and long turnaround times defeat the flexibility that makes UCA competitive. Converting smaller planes like Cessna Caravans into UCA is certainly possible, but I doubt whether it is worth the development cost. The modifications to the flight control system with its mechanical linkages may not always be straightforward, and certification costs may be prohibitively high. If UCA prove to be successful, standardized conversion sets may become available, but my hopes are not high for this. Simple purpose-built UCA like the Singular Aircraft FlyOx, with their integrated ground control stations, may appear on the secondhand market in 10-15 years as alternatives to converted manned aircraft.
What about UAVs built for other purposes? The number of types of UAVs is very large, but some general remarks can be made. A UCA should have a cargo volume of at least 300-500 liters (assuming a specific cargo weight of 0.3 kg/liter). The cargo hold should be close to the center of gravity, should have no internal obstructing parts and must be easy to reach for loading and unloading. It should also be able to withstand structural loads imposed by the cargo. Pressurization is not needed, but some form of temperature control may be required. Many UAVs are built for surveillance, inspection or photography, and carry their sensors in the front. This will make the sensor bay unsuitable for cargo, even if it is large enough. When the payload bay is situated in the middle of the aircraft it is often not easily accessable for cargo, because of the small size of access hatches, because the landing gear is in the way or because ground clearance is too little. Generally, I would conclude that only UAVs that have cargo transport 'designed into them' as one of their possible applications are suitable for use as UCA.
What fate awaits pilots?
It is to be expected that UCA will initially be used in markets where there is no competition from manned aircraft. After all, the advantage of UCA is that they can be profitable on routes where manned aircraft are too expensive. So, initially, pilots need not fear the loss of their jobs. When UCA get more common they will likely be used for tasks like intracontinental package transport. This does threaten pilots' job security and may prevent them from accumulating the flight experience on small aircraft they need to qualify for jobs at major airlines. However, the number of 'pure' cargo flights is limited. Only about 10% of large civil aircraft are dedicated freighters; about half the volume of airfreight is transported in the bellies of passenger aircraft. This means that the influence of UCA on the job market for pilots is likely to be much more limited than the ups and downs in pilot demand caused by the economic well-being of the air transport market at large. Furthermore, the introduction of UCA will progress so slowly that the present generation of pilots will not have to worry much about it. However. UCA will likely be followed by unpiloted passenger aircraft. These will, in my view, have a much bigger impact on pilot demand. It is conceivable that in 30-50 years civil aviation will be largely unpiloted. I do not say 'unmanned', for the need of a cabin crew will remain. It is likely that eventually the era of the traditional airline pilot will come to an end.
Tunnel in the Sky
A major barrier to the introduction of UCA is the problem how to integrate them into controlled airspace. Until standardized 'sense & avoid' equipment is certified worldwide and procedures like protocols for communicating with air traffic controllers are developed, UCA will be confined to dedicated airspace. A possibility to have UCA operating on predetermined routes is the 'Tunnel in the Sky', concept, coined by former Airbus engineer Julian Hasinski. This comprises a virtual block of airspace, stretching from origin to destination, with a diameter of, say, a quarter of a mile or so. All traffic except UCA is banned from this tunnel. This concept provides a simple way of separating UCA from manned aircraft in controlled airspace. It is insufficiently flexible to accommodate large numbers of UCA, but very useful during the introductionary phase.
The theoretical advantages of UCA over other modes of transport for specific applications like unlocking isolated regions are undeniable, but still need to be proven in practice. There is hesitation from potential users like airlines to invest in UCA, and established aircraft manufacturers are still wary of entering this market. I believe that smaller, innovative firms, some of which are members of the Platform Unmanned Cargo Aircraft, will be instrumental in introducing innovative designs that will maximize the potential of UCA. By setting up a regular feature covering UCA, aircargopedia.com can provide a worthy contribution to making relevant actors aware of the potential of this new form of aviation.
For more information on unmanned cargo aircraft, visit www.platformuca.org
Hans Heerkens Ph.D is assistant professor at the University of Twente (Netherlands) and does consultancy work on the aviation industry and decision making for the Dutch Ministry of Economic Affairs, the Hague Institute for Strategic Studies and others, focusing on the interplay between technological, economic and management issues. He has made a large number of contributions on the aviation industry and decision making in national and international journals. He is chairman of the Platform Unmanned Cargo Aircraft (PUCA). Some relevant publications are:
1: Heerkens, H. (2013). The future of unmanned flight. Airneth. Online publication: http://www.airneth.nl/news/details/article/the-future-of-unmanned-flight/
2: Heerkens, H. (2015). Safety in commercial aviation. In: Svensson, S., and Steenhuis, H. (2015): The global commercial aviation industry. Abingdon: Taylor & Francis. ISBN: 978-0-415-81821-6.
3: Heerkens, H. & Tenpelman, F. (2016). The military potential of unmanned cargo aircraft. In: Armed Forces for 2020 and beyond. Vienna, Bundesministerium für Landesverteidigung und Sport, 55-71.
For online publications about unmanned cargo aircraft, please refer to the website of the Platform Unmanned Cargo Aircraft: www.platformuca.org