SureFly personal helicopters using drone simplicity to disrupt aviation industry
Image credit: SureFly
Forget flying cars: ditch the compromise and trade up to a personal helicopter. That’s the spin for SureFly, a disruption in aviation tech that could change the world of personal transport.
Helicopters have an image problem: they are seen as complicated, difficult to fly and not generally as safe as winged aircraft. Ohio-based electric truck manufacturer Workhorse is set to change all that with its SureFly personal helicopter that’s as easy to fly as a drone and is stacked with redundant safety systems. CEO Steve Burns says “helicopters have not changed substantially in their 78-year history; we are trying to reinvent the helicopter”.
Cynics may dismiss this as hype: isn’t this dream of personal aerial transport all a bit Buck Rogers? And what’s a truck manufacturer doing at the Paris Air Show, displaying an oversized drone? The thing is, today’s entrepreneurs have no issues with crossing industry boundaries; why else would Elon Musk feel empowered to build electric cars and launch rockets to the International Space Station?
Founded about a decade ago, Workhorse has been selling electric vehicles for four years now, says Burns: “UPS has hundreds of our delivery vehicles on the road and we’ve taken more than 5,000 orders for the W-15 pickup truck.” The great thing about being an electric truck maker as opposed to an aircraft manufacturer, he says, is that “it allowed us to break all the rules!”. The company does, however, have some experience with aerial vehicles, having developed the HorseFly UAV for home package delivery, a system tested by UPS in February.
So let’s unpick that claim of reinventing the helicopter, based on the issues of complexity, operating difficulty and safety.
A typical helicopter rotor head looks incredibly complicated, largely because the pitch of the blades must be adjustable to control lift and, for steering, the blades must angle back and forth as they rotate (to produce more lift on one side of the craft than the other, which executes a turn). And because the rotor blades produce a torque that would tend to rotate the helicopter about the vertical axis, copters need a tail rotor to counteract it. As implied above, SureFly has fixed-pitch props and works like a drone in that steering is achieved by simply changing the rotation speed of the individual rotors to vary lift. Meanwhile, rotor pairs rotate in opposite directions to counteract torque.
The pilot flies the vehicle with a joystick, in what is probably a fairly intuitive fashion, and the onboard computer does the rest. It’s a standard “fly-by-wire design”, explains Burns, with a processor making decisions “hundreds of times a second”.
“Anyone familiar with a drone will find it very easy to fly,” adds Burns. Instead of all the preparation required for a conventional helicopter, “it’s like instant-on and fly” with controls and instrumentation pared down to “a joystick and an iPad”.
A generator powered by premium unleaded petrol is used to charge batteries in-flight, thus eliminating the need for long recharge times on the ground, which means that the vehicle can be ‘turned around’ quite quickly, much like a diesel-electric hybrid car.
As for safety, engineers will appreciate the SureFly’s redundancy design in that four out of eight rotors and one of two battery packs can fail and it can still fly. If the petrol engine – which acts as a generator for battery charging – fails, the craft has five minutes of battery power to allow it to land safely. If that should fail there is a ballistic parachute, ejected from its container by a pyrotechnic charge. The carbon-fibre structure is specified for a “24g hard landing”, according to Burns.
So what is the target market? Currently, it includes anyone from farmers tasked with crop spraying to high-end city commuters. A graphic released by the company shows a SureFly hopping from one city building top to another, though airport-to-downtown would be an equally valid journey. In fact, according to Patrick Conners, Workhorse Group manager for manned aircraft, the most efficient flight trajectory is reckoned to be a “vertical lift to altitude followed by a gradual linear descent”, because “much more thrust is required to fly forward”.
This operational procedure is adequate, as the flight ceiling is only 1,200m and the average flight is predicted to be “less than 10 miles”. With a top speed of 70mph, it could fly considerably further, but the wingless design is optimised for short hops.
SureFly was unveiled at the Paris Air Show in late June, so it’s too early to make firm sales predictions but, when interviewed mid-week, Burns confirmed that they’d been “taking orders since Monday”.
Other potential customers include emergency responders and “the military”, so it’s clear that SureFly is not relying on existing private aircraft pilots and owners of super-yachts. That said, the target price of “under $200,000” seems remarkably affordable for those with a reasonably high disposable income – especially considering that the Aeromobil ‘flying car’, also on display at the show, sells for a cool $1.2m. Although SureFly is being marketed as a two-seat vehicle, clearly it could be adapted to carry cargo instead.
According to Burns, ground testing is almost complete and flight testing is planned for later this year, with Federal Aviation Administration certification expected in 2019. Technically, SureFly is described as an eVTOL (electric vertical take-off and landing) aircraft. In practice, Burns expects it to be “classified as a light sport aircraft...accessible to someone with a license obtained with about 20 hours flying”.
Future goals for the company include a winged eVTOL version with tilting rotors for longer ranges and an entirely autonomous variant that could carry two fare-paying passengers. This may well be a leap too far for some, but it is all part of the current conversation about autonomous vehicles. The development of the unmanned drone or UAV, with applications from ‘plaything’ to ‘bomb delivery system’, has disrupted the aviation industry. The convergence of drone technology and passenger vehicles represented by SureFly’s reinvention of the helicopter could do the same.
Power: 200hp (150kW) gasoline generator with lithium-battery backup
Weight: Kerb weight 500kg
Max. take-off weight 680kg
Top speed: 112kph (70mph)
Flight ceiling: 1,200m (4,000ft)
Flight-duration capacity: 1 hour
Target price: “under $200,000”