INTERVIEW: H55’s Andre Borschberg on Safety, Certification and the Reality of Electric Flight

Fol­low­ing H55’s announce­ment yes­ter­day (Mon­day), eVTOL Insights Exec­u­tive Edi­tor Jason Pritchard was giv­en the oppor­tu­ni­ty to speak with the company’s co-founder André Borschberg, who talked more about the lat­est mile­stone in its bat­tery cer­ti­fi­ca­tion pro­gramme, why safe­ty must come before speed and how col­lab­o­ra­tion will define the future of elec­tric and hybrid avi­a­tion.

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As part of its test cam­paign, H55 pro­duced more than 100 test arti­cles drawn from its approved and audit­ed prod­uct con­fig­u­ra­tion.

The six-month effort cov­ered envi­ron­men­tal, safe­ty, func­tion­al, and per­for­mance con­di­tions under worst-case fail­ure modes, includ­ing author­i­ty-wit­nessed ther­mal run­away tests with­out prop­a­ga­tion. Col­lec­tive­ly, these results con­firm readi­ness for cer­ti­fi­ca­tion and indus­tri­al deploy­ment, includ­ing:

• Com­ple­tion of the cer­ti­fi­ca­tion cam­paign for propul­sion bat­tery mod­ules
• Con­fir­ma­tion that H55 remains the only organ­i­sa­tion hold­ing both EASA Design Organ­i­sa­tion Approval (DOA) and Pro­duc­tion Organ­i­sa­tion Approval (POA) for elec­tric propul­sion sys­tems
• Pro­duc­tion of series-man­u­fac­tur­ing-con­form­ing propul­sion bat­tery mod­ules
• Com­ple­tion of the first EASA-val­i­dat­ed cell char­ac­ter­i­sa­tion cam­paign for cer­ti­fied propul­sion bat­tery sys­tems
• The safe­ty demon­strat­ed dur­ing test­ing com­plet­ed in Decem­ber 2025 is now being doc­u­ment­ed into final test reports, which H55 is sub­mit­ting to EASA for for­mal accep­tance in Q1 2026

After sev­en years of inten­sive devel­op­ment and test­ing, Borschberg believes its work could help unlock the next phase of elec­tric avi­a­tion.

“We start­ed deal­ing with elec­tric air­planes at Solar Impulse,” Borschberg explained, ref­er­enc­ing the his­toric solar-pow­ered flight around the world com­plet­ed in 2016. “But after that achieve­ment, we decid­ed to con­tin­ue devel­op­ing this tech­nol­o­gy with a strong focus on two things: cer­ti­fi­ca­tion and safe­ty.”

Accord­ing to Borschberg, the bat­tery remains the most crit­i­cal, and most chal­leng­ing, ele­ment of elec­tric and hybrid air­craft.

“What­ev­er solu­tion you choose, ful­ly elec­tric, hybrid, or even fuel cell, the bat­tery is always there,” he said. “And it’s the most dif­fi­cult part to con­trol, because it’s where the high­est risks are, espe­cial­ly when it comes to fire.”

Sev­en years to reach cer­ti­fi­ca­tion readi­ness

By com­plet­ing this reg­u­la­tor-approved propul­sion bat­tery mod­ule test cam­paign, H55 says it has mate­ri­al­ly reduced the pri­ma­ry con­straint that deter­mines which elec­tric avi­a­tion tech­nolo­gies can com­mer­cialise. For­mal demon­stra­tion of con­tain­ment under worst-case fail­ure sce­nar­ios mate­ri­al­ly reduces reg­u­la­to­ry and insur­ance expo­sure, unlock­ing repeat­able, cer­ti­fi­able deploy­ment across air­craft pro­grams, while ensur­ing air­craft-lev­el safe­ty.

With this achieve­ment, H55 is tran­si­tion­ing from val­i­da­tion to scale. A sin­gle, cer­ti­fi­able Ener­gy Stor­age Sys­tem archi­tec­ture can now be deployed across mul­ti­ple plat­forms, allow­ing cer­ti­fi­ca­tion evi­dence to com­pound as rev­enue poten­tial expands with­out pro­por­tion­al increas­es in devel­op­ment cost, sup­port­ing repeat­able deploy­ment across fleets and air­craft life­cy­cles rather than one-off pro­gramme deliv­er­ies.

H55’s new­ly val­i­dat­ed bat­tery pack has been designed ini­tial­ly for Part 23 fixed-wing air­craft, typ­i­cal­ly seat­ing between two and 19 pas­sen­gers. The cer­ti­fi­ca­tion cam­paign required not only a ful­ly mature prod­uct, but also a pro­duc­tion-ready man­u­fac­tur­ing line, some­thing Borschberg says is often under­es­ti­mat­ed across the indus­try.

“You can­not cer­ti­fy a pro­to­type,” he stat­ed. “You have to cer­ti­fy some­thing that is already in pro­duc­tion. That means you must ful­ly devel­op the prod­uct and the pro­duc­tion line before you even start the cer­ti­fi­ca­tion tests.”

That real­i­ty, he added, explains why the process took sev­en years.

“You nev­er suc­ceed the first time. We had sev­er­al iter­a­tions before reach­ing this point,” Borschberg said. “But today, we have a bat­tery pack that is extreme­ly safe for avi­a­tion.”

A dif­fer­ent approach to fire safe­ty

One of the most notable aspects of H55’s tech­nol­o­gy is its approach to ther­mal run­away and fire con­tain­ment. While many man­u­fac­tur­ers aim to con­tain fires at the bat­tery mod­ule lev­el, H55 chose a more gran­u­lar strat­e­gy.

“Most peo­ple try to con­tain fire with­in the bat­tery mod­ule,” Borschberg explained. “That means every­thing inside the mod­ule can burn. As a pilot, I would not be very pleased to have a tita­ni­um box behind me reach­ing 1,000 degrees.”

Instead, H55 focused on con­tain­ing fail­ures at the indi­vid­ual cell lev­el.

“We delib­er­ate­ly trig­ger cells to burn and then demon­strate that there is no prop­a­ga­tion,” he said. “To do that, you need a very deep under­stand­ing of cell behav­ior — charged, uncharged, explod­ing, burn­ing. It’s extreme­ly com­plex.”

This phi­los­o­phy, he believes, is fun­da­men­tal to mak­ing elec­tric avi­a­tion viable at scale.

“Fire con­tain­ment is crit­i­cal for all appli­ca­tions,” Borschberg said. “If you get that right, you estab­lish the foun­da­tion for safe­ty.”

Fixed-wing first, eVTOL next

While much atten­tion in Advanced Air Mobil­i­ty is focused on eVTOL air­craft, Borschberg sees fixed-wing avi­a­tion as the log­i­cal start­ing point for cer­ti­fied elec­tric flight.

“A fixed-wing air­craft is sim­pler to cer­ti­fy,” he not­ed. “Espe­cial­ly when you take an already cer­ti­fied air­craft and mod­i­fy it with elec­tric propul­sion.”

H55 is cur­rent­ly work­ing close­ly with man­u­fac­tur­ers and oper­a­tors — includ­ing in the flight-train­ing sec­tor — to sup­port first cer­ti­fi­ca­tions and deliv­er­ies as ear­ly as next year in both Europe and the US.

“For us, the pri­or­i­ty now is to help man­u­fac­tur­ers cer­ti­fy their air­craft using our tech­nol­o­gy,” Borschberg said. “We’re not just devel­op­ing sys­tems — we’ve been fly­ing elec­tric air­craft since 2009. That expe­ri­ence is crit­i­cal.”

He added that data gath­ered from cer­ti­fied gen­er­al avi­a­tion air­craft will play a key role in unlock­ing more com­plex plat­forms.

“This will help author­i­ties gain con­fi­dence,” he said. “If you want to bring large lithi­um bat­tery sys­tems onto trans­port air­craft, you must prove — with real data — that they are safe.”

Col­lab­o­ra­tion over ver­ti­cal inte­gra­tion

Look­ing across the wider elec­tric and eVTOL land­scape, Borschberg believes the indus­try is begin­ning to reassess ear­ly assump­tions around ver­ti­cal inte­gra­tion.

“Many projects tried to do every­thing them­selves — cells, bat­ter­ies, motors, flight con­trols,” he observed. “That was under­stand­able in the begin­ning, because there were few expe­ri­enced sup­pli­ers.”

But he ques­tions whether that approach is sus­tain­able.

“The task is immense. It takes too much time and mon­ey, and it’s very dif­fi­cult to be the best at every­thing,” Borschberg said. “I believe more com­pa­nies are real­iz­ing that part­ner­ing with spe­cial­ists is the faster path for­ward.”

H55, he hopes, can play a cen­tral role in that ecosys­tem.

“The bat­tery will remain a core ele­ment of elec­tric and hybrid air­craft,” he said. “By stan­dard­iz­ing this part and bring­ing cer­ti­fied solu­tions, we can help accel­er­ate the entire indus­try.”

As elec­tric avi­a­tion con­tin­ues its slow but steady pro­gres­sion toward com­mer­cial real­i­ty, Borschberg remains both real­is­tic and opti­mistic.

“We’ve all been frus­trat­ed by the pace,” he admit­ted. “But reach­ing this mile­stone is a big step — and I tru­ly believe it can help move the indus­try for­ward.”