H55 Successfully Completes All Regulator-Required Propulsion Battery Module Certification Tests

H55 has com­plet­ed the indus­try’s first reg­u­la­tor-required and author­i­ty wit­nessed propul­sion bat­tery mod­ule cer­ti­fi­ca­tion test sequence, address­ing a crit­i­cal gat­ing fac­tor the com­pa­ny says has con­strained the com­mer­cial­i­sa­tion and financ­ing of elec­tric air­craft pro­grams.

Com­plet­ed in Decem­ber 2025, the EASA-super­vised cam­paign pro­vides cer­ti­fi­ca­tion-lev­el evi­dence that com­mer­cial lithi­um bat­tery cells can be inte­grat­ed into avi­a­tion propul­sion bat­tery sys­tems capa­ble of safe­ly con­tain­ing worst-case fail­ure sce­nar­ios, espe­cial­ly fire prop­a­ga­tion.

André Borschberg, Exec­u­tive Chair­man and Co-Founder of H55, said: “H55 was cre­at­ed with a sin­gle objec­tive: to make elec­tric avi­a­tion cer­ti­fi­able, not just pos­si­ble. From the out­set, that meant design­ing sys­tems around avi­a­tion safe­ty stan­dards and pre­vent­ing fail­ure while opti­mis­ing per­for­mance.

“This mile­stone val­i­dates that choice. Elec­tric avi­a­tion can be engi­neered to meet the same cer­ti­fi­ca­tion dis­ci­pline and safe­ty expec­ta­tions as con­ven­tion­al air­craft. At H55, dis­ci­plined, focused ambi­tion is what trans­lates cer­ti­fi­ca­tion into real mar­ket adop­tion and scal­able com­mer­cial impact.”

About the Test Cam­paign

To exe­cute this 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

From Val­i­da­tion to Scal­able Cer­ti­fi­ca­tion

The test cam­paign was con­duct­ed in a cer­ti­fied pro­duc­tion facil­i­ty using ser­i­al-con­form­ing hard­ware (not pro­to­types) man­u­fac­tured through val­i­dat­ed process­es. It con­firms H55’s abil­i­ty to engi­neer and man­u­fac­ture propul­sion bat­tery sys­tems built to cer­ti­fi­ca­tion stan­dards on reg­u­la­to­ry-approved man­u­fac­tur­ing lines and sup­ply chains.

H55’s unique, patent­ed Ener­gy Stor­age Sys­tem design embeds mon­i­tor­ing, redun­dan­cy, and haz­ard mit­i­ga­tion at the cell lev­el as foun­da­tion­al prin­ci­ples, ensur­ing con­tain­ment of extreme fail­ure con­di­tions con­sis­tent with avi­a­tion safe­ty require­ments.

This approach estab­lish­es a repeat­able cer­ti­fi­ca­tion path­way for H55’s bat­tery tech­nol­o­gy, rather than advanc­ing a sin­gle air­craft pro­gramme. 

By defin­ing a cer­ti­fi­ca­tion-grade bat­tery mod­ule ref­er­ence frame­work, H55 mate­ri­al­ly reduces adop­tion risk for air­craft man­u­fac­tur­ers, oper­a­tors, insur­ers, and investors by enabling actu­ar­i­al risk assess­ment based on author­i­ty-val­i­dat­ed fail­ure data rather than pro­gramme-spe­cif­ic assump­tions. 

With cer­ti­fi­ca­tion evi­dence able to com­pound across a wide range of air­craft plat­forms, cap­i­tal, engi­neer­ing resources, and indus­tri­al capac­i­ty can expand with­out pro­por­tion­al increas­es in pro­gramme-lev­el uncer­tain­ty.

The sys­tem foun­da­tions estab­lished through H55’s first con­form­ing propul­sion bat­tery sys­tem now sup­port accel­er­at­ed devel­op­ment and reg­u­la­to­ry progress for both ful­ly elec­tric and hybrid-elec­tric air­craft. 

The data, infra­struc­ture, and cer­ti­fi­ca­tion-stan­dard evi­dence pro­duced through this cam­paign under­pin mul­ti­ple ongo­ing cus­tomer pro­grammes, includ­ing the BRM B23 Ener­gic, CAE’s tran­si­tion toward all-elec­tric pilot train­ing plat­forms, and the hybrid-elec­tric Dash 8 demon­stra­tion pro­gramme with Pratt & Whit­ney Cana­da.

With more than 20 years of elec­tric avi­a­tion expe­ri­ence, six elec­tric air­craft designed, built, and flown, and over 2,000 ful­ly elec­tric flight hours accu­mu­lat­ed with zero bat­tery-relat­ed inci­dents, H55 brings the oper­a­tional depth required to exe­cute cer­ti­fi­ca­tion-grade pro­grammes — not mere­ly com­ply with them.

Clear­ing the Cer­ti­fi­ca­tion Bot­tle­neck to Enable Scal­able Com­mer­cial­i­sa­tion

Elec­tric avi­a­tion scales on cer­ti­fi­ca­tion. By com­plet­ing this reg­u­la­tor-approved propul­sion bat­tery mod­ule test cam­paign, H55 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.

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. 

With propul­sion bat­tery-mod­ule cer­ti­fi­ca­tion risk now addressed, elec­tric avi­a­tion moves from spec­u­la­tive devel­op­ment to a cer­ti­fi­able indus­tri­al cat­e­go­ry — reshap­ing how pro­grams are eval­u­at­ed, financed, and insured.

Rob Solomon, Chief Exec­u­tive Offi­cer of H55, added: “This achieve­ment marks a struc­tur­al inflec­tion point for elec­tric avi­a­tion. By com­plet­ing the first EASA-agreed bat­tery mod­ule test cam­paign, H55 has addressed the most crit­i­cal tech­ni­cal bot­tle­neck on the cer­ti­fi­ca­tion path, mate­ri­al­ly reduc­ing risk for air­craft man­u­fac­tur­ers, oper­a­tors, insur­ers, and investors.

“By pro­vid­ing mon­i­tor­ing, active and pas­sive pro­tec­tions of every indi­vid­ual cell, H55 trans­forms the propul­sion bat­tery from a ‘black box’ of latent risk into an actu­ar­i­al­ly trans­par­ent asset, estab­lish­ing cell-lev­el mon­i­tor­ing as the non-nego­tiable thresh­old for both reg­u­la­to­ry type cer­ti­fi­ca­tion and fleet insur­a­bil­i­ty. What’s most excit­ing, is the engine-like busi­ness mod­el this enables for H55.

“In par­al­lel, through a joint mul­ti-author­i­ty Cer­ti­fi­ca­tion Man­age­ment Team, EASA and the U.S. Fed­er­al Avi­a­tion Admin­is­tra­tion (FAA) have com­mit­ted to mutu­al recog­ni­tion of agreed means of com­pli­ance for ongo­ing pro­grams. Test results will be trans­ferred to the FAA, pro­vid­ing a basis for sup­port­ing and accel­er­at­ing H55’s U.S. cer­ti­fi­ca­tion activ­i­ties and mar­ket pres­ence.”