Special feature: Delivery by drone during the coronavirus lockdown
- Credit: Tim Cooper
Managing failures without a pilot, UAV corridors, and heavy lift drones. A Covid ‘check flight’ opens the door onto a whole new world | Words & photos: Tim Cooper
Madam was poring over a Skydemon screen. “Have you seen this?” she demanded, jabbing indignantly at a brand new bit of controlled airspace that emanated from Southampton, enclosing Lee on Solent within its 23nm radius. “It’s right down to the surface. Have they gone mad?”
I peered at the screen and harrumphed. I vaguely recalled a news item I had seen about a Covid-19 related drone delivery trial.
Medical supplies were to be transported across the Solent from Portsmouth to the Isle of Wight. The Tower at Lee confirmed this was the case, it wouldn’t prevent the “engine health flight” that was planned that glorious April day, they said. Tower added that the drone was sharing space in our hangar.
A blissfully traffic-free trip along the coastal motorway found us at Lee’s automated west gate. We dialled the code, the gate slid open and hey presto! we were onto the airfield without any human contact. Strange that this counts as a success.
There was little sign of life?the post-pestilence normal. Our Fuji FA 200, ‘MDAM’ would be glad to see us. What self-respecting flying machine wants to lurk in the back of a hangar on a day as perfectly glorious as this?
We drove the short distance from the gate to Tango Hangar, MDAM’s home. We were surprised to see two large vans, all bristling with antennae, parked on the small apron and surrounded by men in masks.
Intrigued, we parked on the grass at the end of the row of their cars and donned our own masks (we know whose is which because we have drawn smiley faces on them and Madam’s smile is bigger than mine). Spinner, the tiny Ugandan airport dog, perked up. She loves people. People mean treats.
A strange looking aeroplane, MDAM’s new hangar mate, was upon the apron. We waved at the masked men, and by sign language made clear that we were going to pull MDAM out of the hangar. It is peculiar how wearing a protective face mask changes our interactions with our fellow humans.
Our voices are muffled and unintelligible, our half covered faces impede our facial expressions (if I remember rightly, non-verbal communication accounts for ninety percent of our personal interaction). Perhaps we will eventually evolve, and those of us with expressive eyebrows will be better placed than those with expressive mouths.
Newbie in the hangar
MDAM’s new best friend, G-CLLU, is a strange looking, sizeable, silvery machine: two engines, one each side of a substantial lifting body; a set of high aspect ratio wings with a most intriguing array of segmented control surfaces outboard of the engines; a high-set horizontal tail surface bridging the two tall vertical stabilisers which are mounted upon the ends of each of the twin tubular booms which sprout from the back of the engines.
The rugged, trailing link main landing gear is steeply raked back. From the front ’LU has a cheery, anthropomorphic countenance?two cute smiley faces in lockstep?a cartoon Castor and Pollux.
Oh yes, I think, trust you to look cute. Deceiver. UAVs seem inhuman to me, because there is something emphatically missing?the human. This renders them sinister. A reminder that we’re not really needed; indeed, as you will read, the technology being developed in this particular drone is yet another step along that path.
Perhaps a quantum step. It shouldn’t really bother me?I always maintain that I wouldn’t fly were it not for aerobatics. But when I see UAVs up close and in the tin then I back-pedal. Manned flight?that’s where the glory resides. UAVs subtract the magic from flight, they are exclusively about utility. I like magic and poetry.
Madam and I had started to uncover and inspect MDAM when an energetic, masked man bounded over. He was as intrigued by our machine as we are about his. We showed him MDAM and let him sit in the cockpit. He whipped out his phone and took pictures of the cockpit.
“Forgive me”, he muffled through his mask, “I’m a bit of a cockpit wonk.” Jumping off the wing he cast a clearly knowledgeable eye over the Fuji, “strong wing, lots of volume for spars there,” he pointed out, and when Madam lowered the flaps for the preflight inspection he immediately observed, “Fowler flaps, great!”
I introduce Madam and myself. “I’m Jim,” he says, as we proffer elbows in the absence of proper but forbidden British handshakes. A raised elbow lacks warmth and human contact, and doesn’t allow us to form impressions the way a handshake does. I suppose it does preserve us from certain death, though.
Jim digs out a business card from a pocket and hands it over. Should I read it or wipe it down with an alcoholic wet wipe? I settle for reading it: University of Southampton, it says, Computational Engineering and Design Research Group. It doesn’t stop there, this card: Professor Jim Scanlan, FRAeS, Professor of Aerospace Design, Co-Director Rolls-Royce UTC in Design. Well, that explains how he knows what a Fowler flap looks like, then.
I sense a story here. I can see the byline and headline: By our Special Correspondent, from Somewhere In Southern England; Boffins Test Top Secret Gubbins In Battle With Killer Disease.
So I explain to Professor Scanlan that I sometimes contribute to Mr. Whiteman’s organ, and ask if I might be allowed to write about MDAM’s new chum. Jim is a keen PPL, and a reader of Pilot.
So yes, that would be fine, but on condition that he can see the copy before it goes to press. He tells me there is rather a lot of confidential technology lurking in ‘Lima Uniform’ some of which is commercially sensitive. I break a golden rule of journalism and agree.
The Isle of Wight Covid-19 trial
On the day that we met Jim the country was in Covid-19 lockdown. UK airspace was effectively empty.
A proposal to experiment with ULTRA quickly to deliver critical medical supplies across the Solent was accepted, and a planned exercise was brought forward with the blessing of the Department of Transport, which said, ‘…the Transport Secretary also committed to fast track the launch of a new trial using drones between the mainland and St Mary’s Hospital on the Isle of Wight, helping ensure it is equipped to tackle the virus.
This follows £28m awarded by the government earlier this year to Southampton and Portsmouth councils to carry out drone trials of this kind as part of a wider future transport zone trial’. Excerpts from a press release on the University of Southampton’s website further explained what was going on.
‘Solent Transport… is advancing part of its four-year drone project, which will look to develop an air traffic management system to oversee the safe movement of both manned and unmanned aircraft in shared airspace’.
Jim Scanlan’s credentials are impressive. Jim worked at both BAE and Airbus. When at the latter he was involved with the A380 project, and with the A320’s wing design. He went on to become Head of Manufacturing Research at BAE. He remains closely involved in industry, despite his move to academia, and is particularly closely involved with Rolls-Royce.
Jim’s work with UAVs developed over the last decade while at Southampton University. He decided that he wanted to change the way that his aircraft design students were taught.
So he implemented a new teaching strategy that involved his pupils on a practical level?their courses given new focus by designing, building and flying their own machines.
Jim says, “the UAVs just got more sophisticated,” as he glances at Charlie Lima Lima Uniform?which is known as the Windracers ULTRA (Unmanned Low Cost Transport). ULTRA is the latest in a line of UAVs to come out of Southampton University.
Low cost, heavy lift drone
ULTRA is certainly a serious machine. All 350kg of it. ULTRA was created in response to design brief that calls for an aircraft that can carry 100kg of cargo for 1,000km at a low cost.
Windracers Ltd, a British not-for-profit company, provided the money for the project, which has been running for three years. Windracers’ brief has the object of delivering humanitarian aid to austere locations. Indeed, one of the options for delivering its cargo is by air drop?ULTRA is able to fly low and slow and accurately, and twenty feet above the drop zone open its ‘bomb bay’ doors and drop a package of cargo without damage.
Jim pointed out that when transporting sacks of grain to South Sudan from Nairobi or Entebbe using an Antonov, say, the transport costs exceed the value of the cargo. The low cost aspect of the project has informed the design throughout.
A good example of this philosophy is ULTRA’s engines. When I asked Jim the difference between the machine he is developing and UAVs designed for military use his response was startlingly simple: “two zeros at the end of the price”.
So when it came to choosing engines?and remember this 350kg aircraft is designed to travel the equivalent of Oxford to Edinburgh and back again?Jim turned to America’s Briggs and Stratton, best known in UK for powering lawnmowers.
Their V-twin Vanguard engines are sold with a three year warranty, and have mean times between failures measured in thousands of hours. That is certainly very close to the durability and reliability of a certified aircraft engine but at a much lower price point.
Throughout our discussion Jim referred to his, “very sobering experiences of single points of failure”. As I understand it, Jim’s philosophy is that, wherever possible, multiple cheaper components provide a better pathway to preventing total failures than the incorporation of more expensive single components.
So ULTRA has two off the shelf engines of established reliability rather than the single, certified Rotax engine that you will find on a Predator drone. Much of the test flying that sunny spring day was experimenting with single engine flight.
The engines have been modified by Jim’s team of boffins (British scientists really do have to be called that) so that the engines can be remotely controlled using a FADEC system, but other than that there didn’t appear to be any major mechanical tweaks to the engines which drive small?but quite noisy?Czech-made wooden propellers.
The engines produce about 25bhp each. I formed the impression that while Jim was clearly taking the drivetrain seriously, his main focus was elsewhere in ULTRA.
The low cost philosophy extends into the airframe design. In some ways ULTRA resembles a Sonex kitplane?expanses of flat surfaces for the fuselage, and almost no double curvature anywhere.
The tail booms are straight, carbon fibre, tubular sections and the only compound curves?the wingtips and the engine cowlings?are moulded composites that can be series produced quite cheaply, simplifying production. Take a good look at the beefy trailing link landing gear for instance. I don’t think any of it comes from the Cleveland catalogue?more motor bike... and nothing necessarily wrong with that.
In addition to being cheap and simple to produce, ULTRA is purposely robust, and if needs be, simple to repair in the field. In fact, the aim of the Windracers funders, and of Jim’s University of Southampton team, is to produce a UAV that costs the same as a delivery van.
I needn’t emphasise to Pilot’s readers, used as we are to the cost of our addiction, that this is a most extraordinary ambition.
The delivery van analogy can be seen in the form of the airframe. Jim explains, “most cargo bulks out before it weighs out,” so the centre section of the vehicle (yes, vehicle?it is a UAV) is a voluminous aerofoil lifting section, with a cargo capacity about the same as an hatchback car.
Unmanned failure management
All this is not to say that ULTRA is a simple flying machine. Far from it. Jim, who does not strike me as given to making rash statements, really astonished me when he told me that ULTRA “has easily the world’s most sophisticated autopilot, for which there is a patent pending”.
There are packages of technology on ULTRA that are at the forefront of avionics development. This is the stuff that really fires up Jim and his team of three very talented ex-students; Joe Roberts, Tom Reed, and Alex Horlock.
Which brings me to what they called ‘the Byzantine generals’ problem’?OK, I’d never heard of it either. I spent an age reading about the Byzantine generals’ problem on the web. Definitely worth a read?it is quite fascinating, if brain twisting.
Essentially it is a scenario in computer science in which components are talking to one another, and in which one or more components lie about their state to the other components. The point of the exercise is how the right decisions should be made in the face of unreliable information.
The subject, then, is systems architecture. Think of the 737 MAX scenario, in which the angle of attack sensors disagreed, and in which the central system made fatal decisions about the true state of the aeroplane.
Airbus uses triple redundancy but, Jim points out “all they have done is to transfer a single point of failure to that system”.
A system in which there is a master controller making the decisions has a single point of failure, while a masterless system, Jim explains, “allows democratic control of systems, and eliminates the single points of failure”. Jim says that he just “happened to discover a more elegant way of doing things”.
How does this play into ULTRA? Well, take a very close look at the wing’s segmented control surfaces. Have you ever seen anything like it?
Jim explains that critically activated actuated systems (the current systems architecture philosophy) are vulnerable to single points of failure whereas, in what he terms “over-actuated systems”, multiple redundancy allows the systems themselves to act in a non-hierarchical way to determine the true state of the system. Jim calls this approach “sensor fusion”.
The extremely low price of sophisticated sensors nowadays makes this new design philosophy a realistic and economical goal.
Jim’s mantra is, “if in doubt fit lots of redundancy”. Look at that wing again and you will see what he means?multiple, identical control surfaces, each with a sensor reporting its current state.
Compare this to a wing with just one aileron and one flap each side, and you will get the gist of Jim’s multiple redundancy philosophy. In a UAV there is no human on board to look out of a window and make decisions if things go wrong.
On May Day the CAA announced a formal temporary Danger Corridor for Windracers ULTRA. This is just the start. CAP 1915 was promulgated on the same day. This document sets out CAA requirements, guidance and policy for UAV BVLOS (beyond visible line of sight) operations.
Although the document is ostensibly a response to the Covid-19 pandemic, it seems clear that this blueprint for UAV operations is the signal that we in our small aeroplanes are just going to have to accept that drone operators will be sharing airspace with us from now on. The genie is not going back into the bottle.
Madam, midway through MDAM’s ‘engine health flight’ checked her SkyDemon and was reminded that Southampton’s expanded, down to surface ATZ had become activated while she was airborne. Rudely awaking Solent ATC, which had no other traffic, she was told to switch frequency back to Lee and coordinate the return of her half hour sortie with the Tower.
This was dead easy, but the UAV BVLOS corridor that was introduced just a few days after this flight by the CAA is certainly going to be easier to work with than a gigantic and prohibitive ATZ.
My conclusions are threefold: UAVs are a fact of life and GA is just going to have to deal with this; second, Professor Jim Scanlan with his “more elegant way of doing things” is a man to watch; and finally, if you are a very appealing little dog and you ask nicely, boffins will feed you sausages.