Q&A: Manta Aircraft CEO Lucas Marchesini talks about its ANN series of hybrid-electric vertical and STOL aircraft

With more than 400 eVTOL air­craft con­cepts now cat­a­logued in the Ver­ti­cal Flight Soci­ety’s world direc­to­ry, sev­er­al com­pa­nies enter­ing the mar­ket are mov­ing away from 100 per cent elec­tric propul­sion and focus­ing on hybrid tech­nol­o­gy instead.

One of these com­pa­nies is Man­ta Air­craft. The Swiss start­up is devel­op­ing its fam­i­ly of hybrid-elec­tri­cal ver­ti­cal and short take-off and land­ing (HeV/STOL) air­craft.

Test­ing is cur­rent­ly under­way of a 1:3 scale demon­stra­tor, which is being used to test and assess the basic fly­ing char­ac­ter­is­tics. A final con­fig­u­ra­tion of the pro­to­type is expect­ed to start fly­ing in 2022.

Man­ta Air­craft’s two-seater mod­el, called ANN2, fea­tures eight elec­tric duct­ed fans and mea­sures just more than 28ft in length, with a 22ft wingspan. The ANN2 is focused more on per­son­al air mobil­i­ty, but the com­pa­ny is look­ing at oth­er appli­ca­tions, most notably the emer­gency response sec­tor. It can trav­el more than 600km with a cruise speed of 300km/h and a larg­er, four-seater ver­sion is also in devel­op­ment.

Speak­ing to eVTOL Insights, Man­ta Air­craft CEO Lucas March­esi­ni says the com­pa­ny is not focused on urban air mobil­i­ty or air taxis, but region­al and inter-region­al air mobil­i­ty. He spoke to us in more detail about its future plans for the mar­ket.

Q: Can you tell us more about the rea­sons why you chose hybrid propul­sion for your air­craft?

Lucas March­esi­ni: “We set our tar­get speed at the begin­ning to be 300 kilo­me­tres per hour and an impor­tant range, so to match this we went for a winged solu­tion with hybrid propul­sion about a year and a half ago.

“At the time, it was not so used because most of the air­craft were rotor­craft and using bat­ter­ies. It was impos­si­ble to reach this speed and range using that con­fig­u­ra­tion, and with winged air­craft you need about one tenth of the pow­er that you need from the rotor­craft to stay in the air. So we decid­ed to take a gas tur­bine which runs on biodiesel or bio-Jet A1, and it pro­vides part of the total pow­er that is required for the ver­ti­cal take-off and land­ing. And the rest of the pow­er is com­ing from the bat­ter­ies.

“So at this point, when we are cruis­ing we use the tur­bine at a rea­son­able range because oth­er­wise, we’d be using it at 15–20 per cent of the max­i­mum pow­er and that does­n’t make any sense. The game in the eVTOL space is to be able to lift as much weight as pos­si­ble. That’s very lim­it­ed because it’s not like an aero­plane where you can increase the length of the run­way by 100 yards and take off with a few kilos more. Here, you either take-off or don’t take off.

“That’s why we decid­ed to pre­pare our air­craft for a short take-off and land­ing oper­a­tion. It has land­ing gear which allows it to oper­ate on semi pre­pared airstrips, grass fields and so on. The idea is to make an air­craft for per­son­alised mobil­i­ty, not as an air taxi, but also to cre­ate a plat­form. We start­ed the con­cept with a sin­gle seater, which was just an exer­cise, and then we began devel­op­ing the two-seater which is the ANN2.  In the back­ground, we’re already work­ing on a four-seater mod­el.

Q: How is devel­op­men­tal test­ing going so far, and can you tell us what your planned roadmap to mar­ket looks like?

LM: “We’re already work­ing on the four-seater and have the one third scale demon­stra­tor built, which we began fly­ing in Decem­ber. The sec­ond one will be ready in the next two months. The scope is to study and devel­op the flight con­trol com­put­er, and to show how the air­craft behaves. We plan to com­plete the design of the ANN2 by the mid­dle of this year, so we can start to assem­ble the air­craft by the end of 2021.

“It’s an aggres­sive time­line, but we’re cur­rent­ly on track. We have a small team of about 22 peo­ple, and plan to dou­ble the work­force but no more than that. A char­ac­ter­is­tic of Man­ta Air­craft is that most of us are com­ing from aero­space, but we also have some DNA from the auto­mo­tive and motor­sport sec­tors.

“We are work­ing with sev­er­al com­pa­nies on this project, includ­ing YCOM who are experts in advanced com­pos­ites and have all the know how to make the pro­to­types. We’re tak­ing the typ­i­cal motor­sport approach, which is that you would start work­ing on a vehi­cle in March and by Decem­ber it needs to hit the track. It’s real­ly fast, but that is part of our core busi­ness.

“We also have BSim Engi­neer­ing which spe­cialis­es in 0D and 1D sim­u­la­tions and helps us sim­u­late the air­craft sys­tems. We’re not invent­ing this inter­nal­ly; we want to take as much off the shelf as pos­si­ble. We focus on the aspects where we can real­ly add val­ue, and for the rest, we focus on part­ner­ships and agree­ments with the best in the field.”

Q: Are you able to talk about the safe­ty case for your air­craft?

LM: “Our plan to mar­ket is to be fast, but we know where the risks are with this tech­nol­o­gy and with cer­ti­fi­ca­tion. This is a well-known air­craft lay­out, and it helps to come up with some­thing that is already well known to the cer­ti­fi­ca­tion author­i­ties. They appre­ci­ate not to be in front of some­thing strange.

“It is known how a canard works and from the flight mechan­ics point of view we have no ques­tion marks there. And it’s safe, if the propul­sion sys­tem stops work­ing you can con­trol it and glide it to make a land­ing.

“Hav­ing a hybrid sys­tem also allows you to be safe in case there is a prob­lem with the gas tur­bine. The air­craft can fly in bat­tery-only mode with the bat­ter­ies it needs for take-off and land­ing, so it can fly to a near­by air­field. It can fly between 15–20 min­utes depend­ing on the alti­tude and air­speed. And more bat­ter­ies can be installed because there are more bays avail­able.

“And if you have trou­ble with the bat­ter­ies, then you can use the tur­bine pow­er­ing the motors; the air­craft is fit­ted with a bal­lis­tic para­chute. That’s the con­cept, the land­ing gear is strong and we have designed the struc­ture accord­ing to crash­wor­thy cri­te­ria.”

Q: Can you tell us the route you’re plan­ning to take in terms of cer­ti­fy­ing your air­craft?

LM: “We think that the cer­ti­fi­ca­tion at the end will be a mix of the cer­ti­fi­ca­tion for air­planes and rotor­craft. There will be require­ments for ver­ti­cal crash land­ings and require­ments in terms of ener­gy absorp­tion by the struc­ture. So we have to take into account that part, and that’s impor­tant.

“We are already in talks with the Euro­pean author­i­ties. A big mar­ket we are tar­get­ing is the USA, so we will also go to the FAA too. We think about the north and south­bound trav­el on the east and west coast, and our air­craft is able to do that.

“We have on board var­i­ous peo­ple who par­tic­i­pat­ed in the cer­ti­fi­ca­tion of var­i­ous air­craft and now the cer­ti­fi­ca­tion frame­work is becom­ing more defined; there are still some ques­tion marks there, and then we apply our best engi­neer­ing judge­ment.”

Q: What mar­kets are you tar­get­ing and how could your ser­vice look like once it is oper­a­tional?

LM: “We are tar­get­ing two mar­kets: one is the pri­vate own­er or a com­pa­ny which wants to have a four-seater air­craft to move peo­ple quick­ly to their loca­tions, because the air­craft can land on space mea­sur­ing 20 metres by 20 metres. So the tar­get is per­son­al and pri­vate trav­el and for those who want to use it to trav­el up to 200 miles away. They can take off from their gar­den if the avi­a­tion author­i­ties have their air­space which allows you to do that.

“The oth­er tar­get mar­ket is for insti­tu­tions which might need the air­craft to replace, in some cas­es, heli­copters. For exam­ple, rapid inter­ven­tion in the case of med­ical emer­gen­cies or nat­ur­al dis­as­ters. You can­not take a big pay­load, but with a four-seater you can take a doc­tor and equip­ment.

“You can also use the air­craft for patrolling or sur­veil­lance of a ter­ri­to­ry. For exam­ple, in the Alps there are many hydro­elec­tric pow­er sta­tions and if there is an issue you have to get there quick­ly. This air­craft can be used by a tech­ni­cian to fly there and land eas­i­ly.

“This can be done with heli­copters, but the total cost of own­er­ship for our air­craft is fore­cast­ed to be one-tenth of a com­pa­ra­ble heli­copter which flies at the same speed and has the same range. You could replace the heli­copter with our air­craft for some mis­sions, and at a much low­er cost.

“It might be the emer­gency ser­vices such as the police or fire­fight­ing ser­vice, which might use it when tack­ling for­est fires or search­ing mis­sions for exam­ple, and we’re also work­ing to install sen­sors on board the air­craft too.”

Q: You men­tioned ear­li­er about the advan­tages of hybrid propul­sion. Why are we not see­ing more air­craft devel­op­ers take this approach?

LM: “I think there was this wish­ful think­ing of hav­ing every­thing green, silent and all-elec­tric, so you could fly from one place to the oth­er with­out any noise or pol­lu­tion. With the bat­tery tech­nol­o­gy of today that is not pos­si­ble. You can fly rotor­craft for 20 min­utes and then you need one to two hours to recharge the bat­ter­ies.

“I did a cal­cu­la­tion when we start­ed this project. There was some dis­cus­sion inter­nal­ly that every­one was doing rotor­craft and bat­ter­ies, but for our mis­sions it is not fea­si­ble. If you have a fleet of air taxis like the cur­rent most seen rotor­craft in a city and want to oper­ate them 18 hours a day, and you can fly them for 20 min­utes but then have to recharge them for one to two hours, you will want to have a bat­tery pack swap sys­tem.

“So in one day, for oper­at­ing a fleet of 100 air­craft for 18 hours per day, you would need to recharge around 4,000 bat­tery packs. Then you won­der who will recharge these packs, what infra­struc­ture will you need for these packs and at what cost. They will last less than 200 days because of going above the 600 cycles, cur­rent typ­i­cal lim­it for the LiPo bat­ter­ies beyond which they lose 20% of capac­i­ty, hence lim­it­ing the dura­tion of each flight.

“And then you have to con­sid­er you may have two min­utes to go to the recharge sta­tion or bat­tery swap sta­tion and then come back. So oper­a­tional­ly, you might only have 10 min­utes of flight. To have some­thing which works on bat­ter­ies today or in the future, you need big infra­struc­ture.

“If you land on top of a sky­scraper, you will need to bring the bat­ter­ies for swap­ping there. How do you bring 200–300 kilos of bat­ter­ies up and down? With the cur­rent build­ing lifts?

“These are things which have shown us that the infra­struc­ture needs to be real­ly big, and we decid­ed we want­ed to make an air­craft that does­n’t need this. So as an extreme mea­sure, you could land the ANN2 near a gas sta­tion, fill up with diesel or biodiesel and then take off again. If we want to offer a sys­tem that does not depend on the build­ing of large infra­struc­ture, we have to find a solu­tion which is eas­i­ly usable.

“The hybrid solu­tion allows you to just fill up the tank with fuel and the tur­bine recharges the bat­ter­ies. I believe more in hydro­gen than bat­ter­ies for long to mid-range flights, but it will take time — maybe in the next five years we’ll see some­thing. I think the most sen­si­ble choice for our mis­sions today is to take a gas tur­bine, which is very light and the pow­er-to-weight ratio is incred­i­ble.”

Q: Any­thing else you’d like to add, Lucas?

LM: “We’re talk­ing with sev­er­al indus­try part­ners which will man­u­fac­ture the air­craft and we’d like to have man­u­fac­tur­ing in the USA as well as Europe. There are sev­er­al which are very will­ing to build the air­craft and have up to 80 years of aero­nau­ti­cal expe­ri­ence. We would­n’t be able to catch up with them on that shall we want­ed to set up a man­u­fac­tur­ing facil­i­ty, so it makes sense to us to bring them into the loop. That was the miss­ing piece from our vision.”