How Audi’s electric sports utility provided a lift – and lift-off – for a remarkable Kiwi-developed unmanned aircraft with sky’s the limit potential.

WITH an XXL-sized radio-controlled model glider on its roof, the car turns into the wind then starts off down the grassy strip … at point just above average human sprinting speed, the craft releases and lifts gracefully skyward.

It all sounds so easy – and looks that way, too, in the accompanying video; the moment when an electric Audi sports utility was employed to launch the Kea Atmos Mk 1 in Canterbury recently.

It was just the second test flight for New Zealand’s first solar-powered stratospheric aircraft, whose 12.5 metre wingspan and a sub-40kg weight lending visual fragility bely the robustness and quality of a high-tech design ultimately tasked to gather high-resolution aerial data for extreme weather events, environmental monitoring and precision agriculture.

That Kea’s latest bird flew without hitch when released from the Audi e-tron Sportback S line loaned by the region’s Audi dealer, Archibalds in Christchurch, was realisation of very careful planning and brought great relief. ‘Simplicity’ was anything but.

The early morning flight from the airfield at Springfield on March 14, captured on video and in photos, was a brief, low altitude foray.

Christchurch-based Kea Aerospace has a loftier goal for Kea Atmos.

The end game is to build a global fleet of solar-powered crew-less aircraft that will fly in the stratosphere for months, soaring higher than commercial airliners.

High altitude flights to realise that optimal 15,240 metre ceiling are planned this year to take-off from Tawhaki, on the Kaitorete Spit, around 50 kilometres south of Kea’s home base.

No surprise, NASA has interest in the ambition of a Kiwi crowd specialist at building and flying a range of electric-powered aircraft and high-altitude balloons.

Their previous opus has been the X10, which flew in February of 2022 for 36 hours non-stop and proved perpetual flight capability at low altitudes.

Kea Atmos goes further, explains Kea Aerospace chief executive officer, Mark Rocket. It’s the first solar-powered stratospheric aircraft designed and built in the southern hemisphere.

Says Rocket: “It’s an incredible challenge to make the aircraft as lightweight as possible to fly in less than 10 percent of the air density we have at sea level, but at the same time it has to be tough enough to handle flying through the fast jet streams.”

MotoringNZ has a healthy fascination in aviation, but its cars we like all the more, so naturally there were questions, starting with: Why an electric Audi?

Phillip Stott, Kea’s chief operating officer, spoke to that one, explaining it went beyond the obvious use of two kinds of electric machine.

“Between the Audi e-tron EV and the Kea Atmos, there are obvious synergies of these two innovative, electric, zero emission vehicles.

“ (But) the reason we were interested in an Audi SUV was because I had figured that a sports utility vehicle might have a slightly softer suspension.

“This is desirable, as we are launching from a grass airstrip, not tarmac, and while the launch speed is only 36 kilometres per hour, we do not wish to expose the lightweight aircraft to unnecessary jolts or vibrations.”

How was the car configured for this?

“Archibalds equipped the e-tron with a roof rack, placed 1.2 metres apart and at a level height. Engineers at Kea Aerospace then built a launch rig, specifically designed for the Kea Atmos Mk 1,” says Stott.

“This rig was equipped with arms that would support the aircraft’s wings while on the ground, but which would then release and drop out of the way just before the aircraft takes flight. This can be seen in the video.”

What were the specific demands for launch? We assume wind direction is important but was there also a set speed?

Stott and Rocket provided a combined response.

“We had maximum headwind and crosswind limits, just like a manned aircraft.

“ … the Kea Atmos Mk1 is a very fragile aircraft, solar-electric powered, optimised for stratospheric flight, with very tight performance characteristics.

“Launch speed was calculated based on wing performance, the weight of the aircraft and a slight head-wind.

“For this specific launch the speed was 29 kilometres per hour … too slow and the aircraft may stall, too fast and the airframe could be destroyed!

“The e-tron's cruise control function was pretty useful in this regard, in that while stationary the target speed could be pre-set and following a touch on the accelerator the vehicle would very smoothly accelerate up to the target speed.”

How did the actual release work (was it a person in the car with a remote?)

Says Rocket: “A person standing next to the pilot on the airstrip, released the clamped aircraft by remote control as the e-tron drove past at the target launch speed.”

What were the potential pitfalls?

Many, agree both men: “Potential pitfalls and risks included the performance of the aircraft being as designed and expected, the calculated launch speed being correct, plus small changes in the prevailing breeze, both in direction and intensity during the 20 second launch run.

“We were able to largely mitigate the variation in breeze by preparing the aircraft the day prior and then launching as soon as possible after sunrise, before significant breeze developed.

However, they added the biggest potential pitfall was actually the human interactions during the launch run.

“… in particular the final two seconds and transition to flight where the e-tron driver achieves the target speed, the co-driver activates a green light on the launch rig, the remote aircraft pilot on the side of the airstrip sees the green light and instructs the controller of the launch rig to release the clamped aircraft by remote control, with the pilot then applying the required power setting to achieve forward flight.

“We are learning and refining our processes all the time and while we practiced extensively, there is also likely scope to simplify some aspects of the launch process in the future.”

How did the relationship between Kea and Archibalds come about - were you all known to each socially, or through business?

Mark Lincoln, marketing manager for Miles Group, into which the Archibalds’ franchise falls, took that one.

“Phillip Stott contacted us directly as a fellow Christchurch business and the home of Audi in our region.

“It then transpired that I actually know one of Kea Aerospace’s directors, Mark Rocket, as I used to work for Mark a number of years ago.”