Flight International - 04

Environment Mobility
“Ultimately, we know that we are not in control of
the process,” Allison says. “Whatever decision they
make, they will make and we will deal with that as
decisions happen. But we’ve been really encouraged.”
New eVTOL designs increase the complexity of certification
because they have different configurations,
multiple thrust sources and various operating modes.
“Many AAM companies are the designer, manufacturer
and operator, requiring them to obtain several
certifications,” the FAA says.
Pilots of eVTOL aircraft will need to be rated to operate
powered-lift vehicles, the FAA says, as many of
the designs involve taking off vertically and transitioning
to forward flight. The agency is developing operational
and pilot-training rules and determining how to
integrate new aircraft types into the existing airspace
system. It expects to update its regulatory framework
for AAM operations in urban areas this year.
Regulatory changes
Additionally, the agency on 6 December 2022 filed a
proposal for subjecting air taxi operations to regulations
that currently apply to airlines and other
commercial operators. Powered-lift aircraft are not
among five existing aircraft categories to which FAA
operating rules apply: commuter carriers, domestic
carriers, flag carriers, on-demand carriers and supplement
carriers. The administrator has proposed adding
powered-lift to the list with its pending rule change.
For inventors, the staggering cost of developing
new technology and getting the FAA’s blessing represents
another significant hurdle. Goldstein has previously
estimated that the price of one aircraft design
to reach certification could be up to $1 billion.
Achieving large-scale air taxi transport in time for
the 2028 Olympics is viewed by some as a highly ambitious
and perhaps unrealistic timeline. Others within
the industry – such as Jia Xu, chief technology officer
of Honeywell’s urban air mobility and unmanned
aerial systems units – say it is entirely possible for
eVTOL start-ups to progress that quickly.
Xu points to the introduction of turbofan engines
and reliable rocket motors as bringing “explosive
growth” to the aerospace industry. He is optimistic
about timelines laid out by Archer, Joby and federal
regulators and is encouraged by the pace at which
EASA and the FAA are moving to support the sector.
Honeywell is doing its part. “Aircraft type certification,
ultimately, is the OEM’s responsibility, but we
are providing them with certifiable components that
“Looking at some of
the partners that we’ve
worked with – Lilium and
Archer as well as Pipistrel
and Textron – they’re past
the point where it’s just
about demonstrators”
Jia Xu Chief technology officer, Honeywell urban air mobility
Skyports
Busy eVTOL operations must align
with existing airspace regulations
have some level of functional guarantees within the
certification regime, so that it reduces the amount of
ocean that they’re boiling.”
Though it has taken multiple generations of demonstration
aircraft to solve a multitude of power, battery
and flight-physics problems, Xu says, several startups
have reached the point of “no kidding, go do it”.
“Looking at some of the partners that we’ve
worked with – Lilium and Archer as well as Pipistrel
and Textron – they’re past the point where it’s just
about demonstrators,” he says. “People are moving
very far along in terms of developing and finalising
their aircraft and sourcing all of the components. The
industry is very serious about moving beyond just
doing demos and into producing conforming aircraft.
“These companies are working very diligently for
certification,” Xu continues. “There’s a host of companies
and partners like Honeywell working somewhat
behind the scenes to make that vision a reality.”
Cost reduction
To minimise costly and time-intensive redesigns,
Archer has, to the extent possible, been using
components similar to those found in existing
type-certificated aircraft.
“We tried to design the vehicle to be as close to
existing regulations as possible, with the newest
stuff,” Goldstein says. “The goal here was to say,
‘Hey regulators, this looks just like all the stuff you’ve
certified before’. We don’t 3D print. We vertically
integrate as little as possible because we want to use
parts that are already on other certified planes.
“We’ve obviously borrowed some stuff from the
helicopter world because we’re vertical flight,” he
adds. “If you’re willing to certify helicopters, you
should be willing to certify these vehicles.”
Xu believes it is wise for air taxi developers to
pursue “certification-ready systems” with “proven
capabilities and pedigree”.
Having explicit support from federal regulators is
encouraging, as well. Creating a certification pathway
for electric air taxis is one thing the FAA “has to get
right”, Nolen said last October. “That work is underway
as we speak and we have a couple of dozen of
[applicants] in the pipeline.”
Certification is, after all, just the beginning. “For the
overall industry to become successful, one thing we
need is a type certificate,” Xu says. “The next one we
need is an operation.” ◗
70 Flight International April 2023