WATCH: AltoVolo to produce full-scale HyperTOL demonstrator after successful testing of Sigma prototype

Alto­Vo­lo has begun pro­duc­tion of the full-scale demon­stra­tor of what it has described as the world’s first Hyper­TOL (Hybrid Per­for­mance Take-Off and Land­ing) air­craft.

Due for com­ple­tion at the end of this year, it fol­lows the suc­cess­ful test­ing of its high per­for­mance Sig­ma pro­to­type. The com­pa­ny also plans to make sev­er­al key strate­gic announce­ments and unveil an upcom­ing pub­lic exhi­bi­tion in the com­ing weeks.

Alto­Vo­lo is tar­get­ing full type cer­ti­fi­ca­tion for the Sig­ma, where it will be in the com­mer­cial air­craft cat­e­go­ry which allows for the most expan­sive use cas­es in both urban and region­al envi­ron­ments. Sport Pilot cer­tifi­cate hold­ers will be able to oper­ate the Sig­ma with just 25 hours of train­ing, but they will be restrict­ed to fly­ing only in fair weath­er con­di­tions and dur­ing day light hours in most cas­es. 

The lim­i­ta­tion of the Sport Pilot license, which allows car­ry­ing only one pas­sen­ger, part­ly informed the deci­sion to con­fig­ure Sig­ma as a two-seater air­craft rather than a three-seater. With reg­u­la­to­ry VTOL require­ments evolv­ing rapid­ly, espe­cial­ly for small­er air­craft man­u­fac­tur­ers, hav­ing close ties with cer­ti­fy­ing bod­ies in Europe and the US is prov­ing  to be invalu­able for time­ly pro­gres­sion towards approvals.  

Design Inno­va­tions 

One of the most notice­able shifts in AltoVolo’s think­ing is a move from elec­tric duct­ed fans (EDFs) to open rotors. The com­pa­ny under­took an exten­sive pro­gram of research and devel­op­ment com­par­ing both open and closed rotor  per­for­mance.

These stud­ies extend­ed to imple­men­ta­tion, cer­ti­fi­ca­tion and com­mer­cial­i­sa­tion where it was found  closed rotors under achieved when all fac­tors are con­sid­ered. The addi­tion­al weight, iner­tia, com­plex­i­ty and rel­a­tive fragili­ty of EDFs mean they are less than opti­mal for an air­craft as ver­sa­tile as the Sig­ma, which is built around a fly  any­where, any­time mind­set.  

The move to open rotors increas­es hov­er time by a fac­tor of two, reduces pro­peller load­ing, and offers notable weight sav­ings with more desir­able tilt tran­si­tion char­ac­ter­is­tics. To max­imise this advan­tage the Alto­Vo­lo team has  devel­oped an effi­cient, high-speed rac­ing prop con­cept with a fixed pitch that out­per­forms any com­mer­cial off the  shelf pro­peller, demon­strat­ing our com­mit­ment to con­tin­u­ous improve­ment and supe­ri­or robust per­for­mance. 

Progress Towards Pro­duc­tion 

Hav­ing com­plet­ed the pre­lim­i­nary design review for the Sig­ma, in which details of the first pro­duc­tion air­craft have  been locked, the focus is now on detailed engi­neer­ing and tick­ing off cer­ti­fi­ca­tion require­ments.

Exten­sive flight test­ing of a quar­ter scale air­craft has con­firmed per­for­mance and con­trol char­ac­ter­is­tics to a high lev­el. This allows  the pro­gram to move on with the pro­duc­tion of the first full scale Sig­ma demon­stra­tor. This air­craft will form the basis  of the man­u­fac­tur­ing readi­ness review set­ting the com­pa­ny up to start ser­i­al pro­duc­tion. The team at Alto­Vo­lo is com­mit­ted to deliv­er­ing a prod­uct that per­forms at the high­est lev­el and ful­fils our mis­sion of deliv­er­ing the lux­u­ry of time.  

Alto­Vo­lo is an aero­space start­up found­ed by design engi­neer Will Wood, who plans to make flight a part of every­day  life by dra­mat­i­cal­ly reduc­ing the cost per pas­sen­ger mile for pri­vate air trav­el. Wood has pre­vi­ous­ly sup­port­ed the  likes of Aston Mar­tin, Fer­rari and Wayve, in con­cep­tu­al­is­ing and engi­neer­ing inno­v­a­tive trans­port relat­ed prod­ucts.  He also led design for a suc­cess­ful US eVTOL start-up in 2024.  

Vehi­cle Con­cept:  

• 2‑seater hybrid elec­tric VTOL air­craft  

Per­for­mance: 

• Hov­er Time: 45mins  

• Pay­load: 270kg 

• Cruise Speed: 165mph 

• Top Speed: 220mph 

• Hybrid Range: 500miles 

• Elec­tric Only Range: 250miles 

• Esti­mat­ed Noise Lev­el, Take-off: 65–70dB(A) @ 100m  • Flight Ceil­ing: 10,000ft (3,050m) 

Weight Dimen­sions:  

• Max Take-off Weight: 980kg 

• Length: 4,050mm 

• Width: 4,900mm 

• Packed Width: 2,250mm 

• Total Height: 1,995mm 

Safe­ty: 

• Bal­lis­tic Para­chute 50ft deploy­ment  

• Thrust Vec­tor­ing Sta­bil­i­ty  

• Con­trol Sys­tem Triple Redun­dan­cy