The FAA makes a U‑turn on its approach to powered-lift, as the eVTOL industry tries to hang on.

Words by Mike Hirschberg, Executive Director at the Vertical Flight Society

On Mon­day, May 9 (the eve of the VFS Forum 78), The Air Cur­rent (TAC) broke the sto­ry that the US Fed­er­al Avi­a­tion Admin­is­tra­tion (FAA) had decid­ed that winged elec­tric ver­ti­cal take­off and land­ing (eVTOL) air­craft that met the FAA’s def­i­n­i­tion of “pow­ered-lift”— a term used near­ly exclu­sive­ly for pilot qual­i­fi­ca­tion rules — could not be cer­ti­fied or oper­ate as “air­planes” (see side­bar for the full text of the FAA’s only offi­cial state­ment).

This meant that cer­ti­fi­ca­tion for winged eVTOL air­craft would have to be done through Title 14 (“Aero­nau­tics and Space”) of the US Code of Fed­er­al Reg­u­la­tions (CFR) Sec­tion 21.17(b). This was a 180-degree change in direc­tion from the path the FAA had been lead­ing the indus­try down for the pre­ced­ing sev­er­al years. 

Part 21 is the “Cer­ti­fi­ca­tion Pro­ce­dures for Prod­ucts and Arti­cles.” Sec­tion 21.17, “Des­ig­na­tion of applic­a­ble reg­u­la­tions,” delin­eates how the FAA can cer­tifi­cate air­craft for which there are already air­wor­thi­ness stan­dards under 21.17(a) — includ­ing spe­cial con­di­tions — and those air­craft with­out such stan­dards. 

The FAA has already accept­ed sev­er­al G‑1 “Cer­ti­fi­ca­tion Basis” issue papers from US com­pa­nies with winged eVTOL air­planes in accor­dance with 21.17(a), with agree­ment that Part 23, “Air­wor­thi­ness Stan­dards: Nor­mal Cat­e­go­ry Air­planes,” was applic­a­ble for these air­craft, sup­ple­ment­ed by spe­cial con­di­tions for the non-wing­borne flight seg­ments. Com­pa­nies with winged eVTOL air­planes, like Joby and Wisk (then called Zee.Aero), had years of meet­ings with the FAA, con­firm­ing this approach, and that they could oper­ate like air­planes.  

Only those eVTOL air­craft with­out wings, such as the mul­ti­copter designs from EHang and Volo­copter, were expect­ing to use 21.17(b), which reads in its entire­ty:

For spe­cial class­es of air­craft, includ­ing the engines and pro­pellers installed there­on (e.g., glid­ers, air­ships, and oth­er non­con­ven­tion­al air­craft), for which air­wor­thi­ness stan­dards have not been issued [empha­sis added] under this sub­chap­ter, the applic­a­ble require­ments will be the por­tions of those oth­er air­wor­thi­ness require­ments con­tained in Parts 23, 25, 27, 29, 31, 33, and 35 found by the FAA to be appro­pri­ate for the air­craft and applic­a­ble to a spe­cif­ic type design, or such air­wor­thi­ness cri­te­ria as the FAA may find pro­vide an equiv­a­lent lev­el of safe­ty to those parts. 

Part 21.17(b) was orig­i­nal­ly devel­oped in the 1980s to cer­ti­fy air­ships like the Zep­pelin N07 and glid­ers to fly in the US air­space. When Bell unveiled its civ­il tiltro­tor in the 1990s, the FAA made the deci­sion that these types of pow­ered-lift air­craft must also use 21.17(b).


Air­craft cer­ti­fi­ca­tion is man­aged by the FAA’s Air­craft Cer­ti­fi­ca­tion Ser­vice (AIR). How­ev­er, last year, the FAA’s Flight Stan­dards Ser­vice Office of Safe­ty Stan­dards (AFS) came to the con­clu­sion that — even if the air­craft could be cer­tifi­cat­ed under Part 23 — pilot cer­ti­fi­ca­tion could not.

This is because in 1997, the FAA cre­at­ed a new cat­e­go­ry of pilot cer­tifi­cates for air­craft defined as “pow­ered-lift” to sup­port the devel­op­ment of the civ­il tiltro­tor. This rule­mak­ing was lim­it­ed only to pilot cer­tifi­cates and pilot schools. Notably, Part 91, 135 and 121 flight rules don’t address the oper­a­tion of pow­ered-lift air­craft in any mean­ing­ful way.

There were sev­er­al ways that the FAA could have addressed the dis­con­nect between air­plane and pilot cer­ti­fi­ca­tion that would have had a min­i­mal impact on the amount of paper­work required by the FAA and appli­cants. For years, the FAA had sup­port­ed the premise that winged eVTOL designs could use air­plane rules for cer­ti­fi­ca­tion and oper­a­tions. Air­plane rules were more con­ser­v­a­tive across the flight rules, and these air­craft could meet the def­i­n­i­tion of an air­plane. 

Indus­try and pilots have had con­cerns with the pow­ered-lift cat­e­go­ry for many years. Mil­i­tary pilots who flew the V‑22 Osprey, AV-8B Har­ri­er or F‑35B Light­ning II were issued pow­ered-lift cer­tifi­cates by the FAA when tran­si­tion­ing to civ­il careers, impact­ing their abil­i­ty to find jobs at air­lines.

Fur­ther­more, the Depart­ment of Transportation’s Fall 2021 semi-annu­al rule-mak­ing agen­da indi­cat­ed the FAA would “remove ref­er­ence to the term pow­ered-lift and des­ig­nate applic­a­bil­i­ty of cur­rent air­plane oper­at­ing reg­u­la­tions for air­craft for­mer­ly referred to as pow­ered-lift cat­e­go­ry air­craft.”

How­ev­er, around the time when FAA Admin­is­tra­tor Steve Dick­son — who had pub­licly stat­ed the FAA’s plans for using Part 23 just a few months ear­li­er — announced his plans to retire on Feb. 17, Flight Stan­dards began a holis­tic review of the dis­con­nect. This led to a com­plete rever­sal on pow­ered-lift, decid­ing, instead of elim­i­nat­ing the term “pow­ered-lift,” to com­plete a com­pre­hen­sive rule-mak­ing effort to intro­duce new flight rules for pow­ered-lift air­craft across 14 CFR.

In the eyes of AFS, the Part 23 path did not align with their new rule-mak­ing intent, as they believed air­craft cer­ti­fi­ca­tion need­ed to match the pilot cer­ti­fi­ca­tion. As a con­se­quence, projects with finalised cer­ti­fi­ca­tion bases must now be repack­aged using 21.17(b) to remove any asso­ci­a­tion of the word “air­plane” from the prod­ucts. 

With sup­port from Act­ing Admin­is­tra­tor Bil­ly Nolen, the FAA has now cho­sen the approach that may gen­er­ate the great­est amount of work for both the FAA and indus­try, and with so many “unknown unknowns” of how and when appro­pri­ate rules will be re-writ­ten. 

Part 23 

At least as far back as 2013, the offi­cial posi­tion of the FAA had been that ver­ti­cal flight air­craft could be cer­tifi­cat­ed under Part 23. The June 2013 doc­u­ment, “A Report from the 14 CFR Part 23 Reor­gan­i­sa­tion Avi­a­tion Rule­mak­ing Com­mit­tee [ARC] to the Fed­er­al Avi­a­tion Admin­is­tra­tion” (which had the sub­ti­tle, “Rec­om­men­da­tions for increas­ing the safe­ty of small gen­er­al avi­a­tion air­planes cer­tifi­cat­ed to 14 CFR part 23”) includ­ed a pho­to of a VTOL air­craft (the 1980s Sky Com­muter) as an exam­ple of the types of inno­v­a­tive ideas that would need to be con­sid­ered under the exten­sive rewrite of the Part 23 air­wor­thi­ness stan­dards that was just then kick­ing off.

This rewrite, under­tak­en in response to the Con­gres­sion­al man­date set forth in the Small Air­plane Revi­tal­iza­tion Act of 2013, was pub­lished in Decem­ber 2016 as the draft Part 23 Amend­ment 64, which went into effect on Aug. 30, 2017. Amend­ment 64 is a per­for­mance-based approach using indus­try stan­dards to meet or exceed the pre­vi­ous lev­el of safe­ty, rather than pre­scrip­tive require­ments that couldn’t accom­mo­date new tech­nolo­gies or inno­v­a­tive approach­es that might come in the future.

As the amend­ment was being draft­ed, it was specif­i­cal­ly writ­ten to accom­mo­date winged eVTOL air­planes. In the Final Rule, the FAA respond­ed to a com­ment from Zee.Aero, stat­ing, “The FAA does not intend to con­tin­ue to use § 21.17(b) for unique cat­e­go­ry air­planes. The FAA plans to shift these unique air­planes from § 21.17(b) to Part 23.”  

Over the past five and a half years, FAA lead­er­ship con­tin­u­al­ly sup­port­ed the industry’s plans that winged eVTOL would be cer­tifi­cat­ed under Part 23, using Part 21.17(a) with spe­cial con­di­tions, rather than as Part 21.17(b), which would be used for air­craft with­out a wing. Tens of thou­sands of man­hours went into con­duct­ing gap analy­ses, work­ing to devel­op the need­ed stan­dards and coor­di­nat­ing close­ly with the FAA. 

The ver­ti­cal flight indus­try knew from the begin­ning that 21.17(b) would be a ter­ri­ble option, based on the long, drawn-out cer­ti­fi­ca­tion of the AW609 tiltro­tor. Although much of the delay was due to the busi­ness and tech­ni­cal changes from the Bell-Boe­ing BB609 to the Bel­lA­gus­ta BA609 to today’s Leonar­do AW609, as well as the tech­no­log­i­cal advances, as much as half of the delay may be due to lack of sup­port and com­pe­ten­cy by the FAA. 

The BB609 civ­il tiltro­tor was first announced in Novem­ber 1996 with the expec­ta­tion that it would be cer­tifi­cat­ed under 21.17(b), using the most appro­pri­ate stan­dards from both air­planes and heli­copters. Now, more than a quar­ter cen­tu­ry lat­er, Leonar­do still does not have accep­tance from the FAA on sev­er­al basic issues.

The lack of agency pri­or­i­ty and atten­tion has drawn the cer­ti­fi­ca­tion out long enough that it has become an embar­rass­ment to the agency and a cau­tion­ary tale of the bureau­cra­cy and pit­falls of the “spe­cial class” cer­ti­fi­ca­tion path. 

Where­to from Here?

In con­trast to near­ly a decade of col­lab­o­ra­tion with indus­try to address the cer­ti­fi­ca­tion of eVTOL air­craft, this deci­sion blind­sided the eVTOL indus­try and was reached in iso­la­tion, with­out any dia­log or input.

The FAA made the deci­sion in late April and appar­ent­ly informed only three of the 16 elec­tric propul­sion appli­cants. After The Air Cur­rent arti­cle appeared 10 days lat­er, the agency stopped com­mu­ni­cat­ing with indus­try, and only respond­ed to queries to reporters with less infor­ma­tion than had orig­i­nal­ly been giv­en to TAC. In fact, the agency had not pro­vid­ed any­thing in writ­ing to its appli­cants before press time. 

How­ev­er, in con­ver­sa­tions with indus­try, the FAA said it will pro­vide an “all-of-agency” effort to expe­dite the devel­op­ment and pub­li­ca­tion of a Spe­cial Fed­er­al Avi­a­tion Reg­u­la­tion (SFAR) this sum­mer to sup­port com­mer­cial oper­a­tions of 21.17(b) air­craft. This must be fol­lowed by a Notice of Pro­posed Rule­mak­ing (NPRM) this fall. 

In remarks to the FAA-EASA safe­ty con­fer­ence in mid-June, Act­ing Admin­is­tra­tor Nolen stat­ed the FAA’s intent to be able to cer­ti­fy eVTOL by 2024 — sug­gest­ing a clear oper­a­tional path would be made avail­able before that time. In par­al­lel, the FAA must coor­di­nate these changes with the US Depart­ment of Trans­porta­tion (DoT) and the Office of Man­age­ment and Bud­get (OMB) — actions the Admin­is­tra­tor’s office should be doing now. 

The good news is that there is now an accept­ed means of cer­ti­fi­ca­tion for winged eVTOL air­craft, and the agency has pub­licly stat­ed that it intends to sup­port the aggres­sive time­lines that the eVTOL com­pa­nies have been work­ing towards — with Joby Avi­a­tion in pole posi­tion for oper­a­tions planned to begin in 2024, and sev­er­al oth­er winged eVTOL air­craft close behind.

Now comes the hard part. It has often tak­en the agency a decade to cre­ate new rules. The FAA must now move at speeds it has sel­dom ever achieved in the past. If it fails, the US will lose its lead­er­ship in eVTOL, and the rest of the world will move for­ward with­out it, much like what hap­pened in the drone indus­try two decades ago. 

Nev­er­the­less, as much as this unex­pect­ed U‑Turn under­mines the good­will and thought­ful col­lab­o­ra­tion of the past decade, what’s done is done. The reg­u­la­tor has made the deci­sion, and indus­try is poised to sup­port the agency’s needs.

In fact, indus­try has no choice but to throw all its weight behind achiev­ing what some think is impos­si­ble. But the FAA will be held account­able if it fails to deliv­er on its promis­es.