Overair shares video which confirms start of propulsion testing for its Butterfly eVTOL aircraft

Overair has con­firmed it has begun the full-scale propul­sion sys­tem test pro­gramme for its But­ter­fly eVTOL air­craft, which rep­re­sents a sig­nif­i­cant mile­stone ahead of the com­pa­ny tar­get­ing its first flight by next year.

Some of the most impor­tant attrib­ut­es of an eVTOL air­craft are safe­ty, com­mu­ni­ty accep­tance, and eco­nom­ic pro­duc­tiv­i­ty in real-world con­di­tions, each of which is large­ly dic­tat­ed by the vehi­cle’s propul­sion sys­tem.

Overair says its vec­tored thrust design and opti­mum speed pro­pellers will allow But­ter­fly to fly safe­ly in unfore­seen cir­cum­stances and diverse weath­er con­di­tions, all with high­er pay­load capa­bil­i­ties. The achieve­ment of this test­ing will help Overair con­firm its design choic­es ear­ly in devel­op­ment.

Jim Orbon, But­ter­fly Pro­gram Man­ag­er at Overair, said: “Achiev­ing our full-scale propul­sion test goals is an excit­ing mile­stone for the But­ter­fly pro­gram. Not only does it allow us to val­i­date our design choic­es and cor­re­late our sim­u­la­tion results to real-world data, but it also proves the team’s tech­ni­cal capa­bil­i­ties and abil­i­ty to exe­cute our devel­op­ment plans. But this mile­stone is a means to an end.  Next stop, full-scale pro­to­type, with long-lead-time parts cur­rent­ly under­way.”

The propul­sion test com­pan­ion video was filmed in the South­ern Cal­i­for­nia desert, where the sys­tem is being eval­u­at­ed in an envi­ron­ment that sim­u­lates some of the most demand­ing aero­dy­nam­ic con­di­tions antic­i­pat­ed in real-world oper­a­tions. The video cap­tures the team sub­ject­ing the pro­peller blades and hub com­po­nents to forces that will be expe­ri­enced dur­ing flight oper­a­tions, as they val­i­date Overair’s flight dynam­ics sim­u­la­tion soft­ware tools.

The devel­op­ment of flight con­trol sys­tems, tilt­ing mech­a­nisms, and the cab­in inte­ri­or are the next pri­or­i­ties for Overair as it tar­gets a first pro­to­type flight by 2023 and con­tin­ues to advance But­ter­fly­’s FAA cer­ti­fi­ca­tion with the goal of enter­ing com­mer­cial ser­vice in 2026.

Based in San­ta Ana, Cal­i­for­nia, Overair’s grow­ing team is har­ness­ing decades of mil­i­tary air­craft inno­va­tion to design, man­u­fac­ture, and oper­ate all-elec­tric ver­ti­cal take­off and land­ing air­craft. With a path to FAA cer­ti­fi­ca­tion in 2025, Overair is ded­i­cat­ed to mak­ing the world a small­er, clean­er place for every­one using But­ter­fly, the most robust, effi­cient, and qui­et air­craft in its class.

Overair’s vec­tored thrust design is aero­dy­nam­i­cal­ly effi­cient and takes the best advan­tage of the com­pa­ny’s unique tech­nol­o­gy inher­it­ed from Karem Air­craft. The com­pa­ny says its But­ter­fly eVTOL air­craft lever­ages Overair’s pro­pri­etary propul­sion design with very large pro­pellers rel­a­tive to oth­ers, while also rely­ing on high­ly effi­cient wing-borne flight for cruis­ing over longer dis­tances. 

As a result of their size, But­ter­fly­’s pro­pellers can spin slow­er dur­ing var­i­ous phas­es of oper­a­tion (hov­er, tran­si­tion, cruise), which makes them qui­eter and draw less pow­er from the bat­ter­ies. Thanks to sub­stan­tial pow­er and con­trol mar­gins, these large pro­pellers pro­vide unmatched effi­cien­cy — an incred­i­bly impor­tant attribute when fly­ing high-tem­po urban routes in var­ied envi­ron­ments.

The propul­sion test­ing fol­lows on from the com­pa­ny announced the expan­sion of its Cal­i­for­nia head­quar­ters at the end of 2021, while Bris­tow Group con­firmed it is work­ing with Overair on its But­ter­fly air­craft as part of a part­ner­ship that includes a pre-order for up to 50 air­craft.