Pushing the Dead-Line

Are electric aircraft developers over-optimistic or over-ambitious in setting their dead-line for when they will be certified and ready to fly customers ?

Have electric aircraft developers been realistic in setting their timeline ?

Times is about up. The market is getting tired of this "Cry Wolf".

By: John Martin Winther Andersen

Having primarily followed the eVTOL market and the later years also the eSTOL / eCTOL market, it has been to say the least noticeable to follow many of the new companies dead-lines for expected aircraft certification, especially for novel aircraft designs that has either never been build and/or commercialized before.

An airplane or helicopter looks like an airplane or helicopter

Simplistic stated, a civilian airplane looks like a civilian airplane, it consist of:

• A fuselage
• Two main wings usually either above or below the fuselage, somewhere midway along the fuselage
• A tail with a rudder and an elevator above or below the rudder
• One or more engines with propeller or shrouded fan(s)

.. and simplistic said the same goes for a helicopter looks like a helicopter, it consist of:

• A fuselage
• A large main rotor with x-number of blades, swash-plate etc.
• A tail with a tail rotor on either side
• A main gearbox, other smaller gearboxes and transmission axels in between
• One or more engines connected to the main gearbox or a transmission axel

An eVTOL is often not like the other eVTOL

But in regards with eVTOL aircrafts, some are based on the same principal design but many others have very unique bespoke designs. Instead of just one primarily design like I described an airplane or helicopter above, with eVTOL we are looking at at least five or really six different principal designs that has little to no resemblance to each other.

• Multicopter, i.e. a scaled up drone with usually 8 or many more propellers, nothing tilts.
• Lift & Cruise, i.e. nothing tilts, all propellers are fixed in either vertical or horizontal position providing either thrust to lift or forward motion.
• Tilt Rotor, i.e. a number of rotors tilt providing both lift and/or forward motion.
• Tilt Wing, i.e. only the main wing tilts with fixed mounted propellers on the wing providing both lift and/or forward motion.
• Augmented Lift or Blown Lift, i.e. air being accelerated over the wings upper surface either by suction from trailing edge fans or propellers, or thrust from leading edge fans or propellers, which provide some lift force and usually additional lift and control is provided by the fans or propellers ability to tilt.
• Mix of Tilt Rotor and Lift & Cruise, i.e. usually with wings leading edge fans or propellers tilting to provide either lift or forward motion and trailing edge propellers or fans fixed horizontally to provide additional lift only.

What does History tell us

Some of the upcoming electric aircraft developers especially in the eVTOL segment has put forward dead-lines for expected final certification only to last a couple of years after having made the first flight of the same platform.

The question this article is asking: Does that sound plausible ?

The best way to evaluate this is to look into history of aviation and compare what we can expect.

There are many aircraft manufactures around the world with decades upon decades of experience and knowledge that has shown how long time it usually takes to get a traditional airplane or helicopter certified after its first flight. For example;

• Airbus
• Bell Helicopter
• Boeing
• Cessna
• Cirrus Aircraft
• Diamond Aircraft
• Embraer
• Leonardo Helicopter (former AgustaWestland)
• Piper Aircraft
• Robinson Helicopter
• Sikorsky
• .. and many more of all sizes

What is common of all of the above is they are all highly experienced developers and manufactures in aviation, in contrast to most eVTOL developers who for most part has hired some highly experienced people from the above companies and other experienced companies, but their company are still freshmen/women in development and manufacturing of aircrafts.

If something is to be learned of the current Boeing Saga is that company culture has great influence in the companies ability to develop and build save aircrafts, consistently and on time.

It would not be fair to compare past history of the complexity of let's say a big Airbus or Boeing aircraft to a small eVTOL aircraft, first of all they are to be certified by two different regulations. So we will compare with the smaller and less complicated traditional airplane and helicopter models. We will also only compare with the recent certified types we can find and see what history tells us how long time a small aircraft or helicopter takes.

Helicopters

• Robinson R66 first flight 2007, FAA certified 2010, EASA certified 2014.
• Kopter AW09 (prev. Marenco) first flight 2014, still not certified by 2024.
• Bell 505 first flight 2014, TCCA certified 2016, EASA certified 2017.
• Bell 525 first flight 2015, still not certified by 2024.
• Airbus H160 first flight 2015, EASA certified 2020
• AgustaWestland AW139 first flight 2001, EASA certified 2003.

Airplanes

• Cirrus SR20 first flight 1995, FAA certified 1998, EASA certified 2004.
• Cirrus SF50 Vision Jet first flight 2008, FAA certified 2016, EASA certified 2017.
• Diamond DA62 first flight 2012, EASA certified 2015.
• Diamond DA50 first flight 2007, EASA certified 2020.
• Embraer Phenom 100 first flight 2007, FAA certified 2008, EASA certified 2009
• Honda HA-420 HondaJet first flight 2003, FAA certified 2015, EASA certified 2016.

.. and the elephant in the house, the first civilian tiltrotor Leonardo AW609, first flight 2003, still not certified by 2024.

What above list of resent examples tells us, is that for even a well established developer and legacy manufacture of aircrafts, for a non-complicated type of aircraft something most of them have build before, it takes from first flight of the final design to final certification between 2 - 7 years.

Add for what is to the company a new thing like another propulsion system (jet instead of piston), pressurization cabin, new type of rotorblades or some additional work to become certified by another aviation authority, and it takes in total between 5 - 13 years.

Or add new tech like fly-by-wire or very different type of flying like a tiltrotor and you might look at 10 to +20 years from first flight and until certification has been accomplished.

Or if you are a new developer / manufacture with a new tech but yet traditional helicopter or airplane you also pass +10 years and that is when you are financially well funded or get help or are taken over by one of the legacy and highly experienced developers / manufactures.

In regards of pretty much all eVTOL developers including the popular developers, the above is not so much an "or" but more an "and", meaning they are challenged from more than just one topic prolonging their road toward certification;

• New company in aviation, having no past aviation company culture to rely on
• New into aviation founders and/or management
• New to develop & manufacture
• New type of aircraft to fly
• New type of propulsion
• New type of energy
• New type of technologies
• Limited funding or not legacy manufactures backed
• .. and finally, brand new legislation that no previous aircraft have been certified by

What we are saying

We are not here to say that a new company in aviation "and" new developer & new manufacture in aviation "and" with a new type of aircraft "and" with a new type of propulsion "and" with new technology can not go from first flight to final certification in just 2 - 3 years.

What we say is that based on decades of aviation history, that historic data from many highly experienced legacy developers & manufactures does not support these optimistic dead-lines many of especially the eVTOL developers have published ...

The more simplistic and traditional design the aircraft is and the more experienced the developers founders are, the lesser time it historically takes to come to market.