Experimental eVTOL innovation

[dapug]

I am looking for definitive answers on this. I have contacted the FAA and EAA with no response. I have also posted on social media to no avail. I'm posting this here in case anyone can answer or connect me to the right people to get a real answer on this...

TL/DR;

How do experimental builders and aviators get involved in eVTOL? Surely this is not reserved only for “taxi” services and commercial interest. What regulations allow for this today, versus future needed regulations?

Full detail:

With all the buzz about VTOL and eVTOL this past year, and the focus primarily being on the concept of “taxi” service (Cora.aero, Uber Elevate, etc), executive/business travel (Eviation, etc), and autonomous transport for non-pilots (Blackfly), it leaves me wondering... what about the rest of GA? What about the Experimental crowd?

There seems to be a huge gap right now in eVTOL, leaving hobbyists and experimental builders completely in the dust.

Perspective setting:

As I see it, there are distinct scenarios where eVTOL is applicable, and not all scenarios require new regulations and complex technologies (such as collision avoidance, autonomy, managing safety in densely populated areas, etc).

EAA members are mostly pilots. We are not trying to solve the need for taxi service in densely populated areas. We are happy to follow the current regulations already in place, and fly and land in the same places that gyro, STOL planes, and helicopters currently fly and land in. We therefore do NOT need complex collision avoidance or autonomy (highly complex, expensive, and time consuming to perfect) nor all the new regulations that obviously are needed there. That will indeed take time, and deep pockets with industry/commercial interests. But for experimental GA aviators and hobbyists, it means our only hurdle is simply the computerized multirotor stabilization; technology that is feasibly within reach.

With that in mind, it opens the following questions:


If I were to build a multi-rotor aircraft today and register it as EAB, what type would it be registered as? It's not a gyro, fixed wing, or even a helicopter or dual-rotor helicopter. It's flight systems and characteristics are entirely different.
If I were to fly an experimental multi-rotor aircraft today, what type rating or endorsement would I need to fly it? Bearing in mind, it does not fly nor handle like a helicopter, the stabilization of which is computer controlled, so the kinds of training and regulation there don't seem to apply.


I see no reason why a hobbyist or community of home builders today cannot do the following:


Design an aircraft capable of VTOL
Fly the aircraft as a certified pilot without the complexity of autonomy or new regulations for non-pilots
Take off, land and fly in the same places and airspace as currently already in place, as already regulated


One might say that RC multi-rotor controllers are not suitable for manned flight. To which I would say I agree, but it sure sets the stage doesn't it? Those RC controllers were built as OPEN SOURCE projects, the community and citizenry literally brought this to the world and to the hobby, and arguably laid the foundation to inspire all those companies we now see applying the concepts to GA and manned eVTOL aircraft. As for the Experimental Aircraft hobbyists, I see no reason why these electronic multi-rotor controllers cannot continue to innovate as a community project with new goals in mind, such as redundancy and safety for manned flight. This is what I mean when I say eVTOL is "within reach" of experimental aircraft builders, not just deep pocketed commercial ventures.

I would love to connect with the right people at EAA or FAA that are knowledgeable on topic and can provide insight.

Experimental innovations in this area are completely stifled if we (the builders and pilots) do not know how our efforts (of building something with the intent to fly) will be allowed and governed in the end.

[Joda]

Sir,

The answers to your questions are not yet apparent. This is a rapidly-evolving segment of aviation, and the FAA has not yet crafted specifics with regard to your questions. With that in mind, I offer you the following comments, which are only my opinions, based on my experiences working with the FAA as a DAR....


If I were to build a multi-rotor aircraft today and register it as EAB, what type would it be registered as? It's not a gyro, fixed wing, or even a helicopter or dual-rotor helicopter. It's flight systems and characteristics are entirely different.

Amateur-built aircraft (as well as other experimental purposes) are certificated as just that - aircraft. They are not necessarily categorized as airplanes, rotorcraft, etc. This is done purposely, so as to allow the very kind of innovation you are talking about. There is no real limit on the nature of your "experiment". However.......


If I were to fly an experimental multi-rotor aircraft today, what type rating or endorsement would I need to fly it? Bearing in mind, it does not fly nor handle like a helicopter, the stabilization of which is computer controlled, so the kinds of training and regulation there don't seem to apply.

The FAA looks at each experiment on its own merit, and will make decisions from the standpoint of protecting the non-flying public first and foremost, and then passengers in the aircraft itself. They will then issue operating limitations to the aircraft based on these safety concerns. To that end, they would need to decide what type of pilot training and credentials would best fit the situation, and will craft the operating limitations accordingly.

Of course, there isn't a clear-cut pilot certificate that fits the aircraft you describe. The closest thing may well be "powered lift", which is the pilot certificate developed for the tilt-rotor type aircraft. That doesn't quite fit your described situation either, but neither does helicopter or fixed-wing airplane. Who knows, they may end up developing a completely separate pilot certification for these type of aircraft. It's just too early to tell.





I see no reason why a hobbyist or community of home builders today cannot do the following:


Design an aircraft capable of VTOL
Fly the aircraft as a certified pilot without the complexity of autonomy or new regulations for non-pilots
Take off, land and fly in the same places and airspace as currently already in place, as already regulated


Agreed. That's what experimental aviation is all about!




I would love to connect with the right people at EAA or FAA that are knowledgeable on topic and can provide insight.

Me too! As described above, it is just to early to be able to give answers to your questions. Frankly, it will likely take someone actually developing such an aircraft and presenting it to the FAA for certification in order to drive this process forward.

Sorry I don't have more complete answers to your questions, but this is the current state of affairs. Stay tuned!

[dapug]

Thanks Joe. Very thoughtful comments.

I'm admittedly interested in what can be done today versus after new regulations that could take years, or decades.

In my case in particular, my primary focus is on an airplane that flys horizontally, intended to fly under the same rules as any aircraft and pilot with a PPL, but happens to land without a runway. I'm not really interested in straight-up "drone" style flying, but the fact that such flight characteristics are needed to land my plane VTOL... this has to be taken into account by FAA signing off on it.

Here is one example of eVTOL (full on manned "drone"), happening right now. These guys seem a little ambitious, but they intend to do manned flight next year in California. I do wonder what analysis on this topic I have raised that they have done. Maybe their aircraft would technically be ready, but what about legalities?

https://airspeeder.com/
https://newatlas.com/airspeeder-manned-multicopter-drone-racing/60385/

[Joda]

Maybe their aircraft would technically be ready, but what about legalities?

Again, anything is legal in the experimental world. The only question that has yet to be answered is, how will the FAA treat the aircraft when they issue the operating limitations. That we won't know until the aircraft is actually presented for certification. Only then will we know what the current state of affairs may be.

As I said before... stay tuned!

[Bill Berson]

Most are flying under FAR103. From my studies and queries there seems to be some confusion about whether the stall speed limit of FAR 103 applies or not.
I didn't see any eVTOL flying at Airventure 2018 or Air Venture 2019.
I think the SureFly may have had a Research and Development airworthiness certificate.
To my knowledge, none in EA-B yet.

[CHICAGORANDY]

The marketing demographic of these multi-rotor 'personal' craft is pretty slim. They can't fly over crowded places, like cities or towns, and yet they cost SO much that it's only in major cities and towns that you'll find buyers with that much disposable income.

For those fortunate enough to live where ultralights can fly? Giddy-Up. For me if nothing else it's interesting to watch this genre of flying machines slowly develop, though at 70 now, I doubt I'll see them become 'popular' or even functional in my lifetime.

[dapug]

Most are flying under FAR103.

I have seen some, but those look like hobby toys. The only commercial vehicle I've seen that is NEAR ultralight is Blackfly (https://www.opener.aero/), but they are actually over Part 103 weight, yet appear to have convinced the FAA to allow flight without a pilot cert, as long as they pass with WRITTEN exam for Private Pilot! That really surprised me.

But I'm specifically interested in the application for EAB, especially because it's not possible to get a real aircraft of this type under UL weight (re: Blackfly, millions invested and still missed the mark). I personally am not interested in "manned drone", but rather, horizontal "fixed" wing flight with VTOL ability. Hence the current dilemma I outlined in the OP.


I think the SureFly may have had a Research and Development airworthiness certificate.
To my knowledge, none in EA-B yet.

Interesting. I'll have to look into this.

[Airmutt]

An interesting and thoughtful discussion. Developing an EAB VTOL aircraft is really pushing the envelope. It offers challenges both to you and the FAA. Fixed wing....are you thinking tilt wing or tilt rotor. Guess you could get really exotic and go with a lift fan. Hope you keep this thread alive with updates on your progress.

[Ron Blum]

But I'm specifically interested in the application for EAB, especially because it's not possible to get a real aircraft of this type under UL weight (re: Blackfly, millions invested and still missed the mark). I personally am not interested in "manned drone", but rather, horizontal "fixed" wing flight with VTOL ability. Hence the current dilemma I outlined in the OP.


Dapug: YOU ARE EXACTLY THE PERSON WE NEED! (and I'm very serious about that.)

Design it, Build it and Fly it as an EAB! There are no regulations stopping you!

I know this is going to generate a whole bunch of terminology issues/arguments/dissention, but … I deal with OEMs, FAA (and foreign authorities), and Experimentals every day of my career. Ultralights are unregulated; LSA are (self-regulated) ASTM concensus standards; EAB are basically unregulated and NOT certificated; and only OEM products are certificated to part: 23, 25, 27, 29, etc. As an EAB you will be subjected to Operating Limitations that you and the FAA (FISDO) will work with you to agreement. NOTHING should stand in your way! In fact if you're looking for help on any of this, let me know. I will do everything I can to keep you going (I didn't say it would be easy). solutions@blueontop.com

Ron "Keeping the Can Do Attitude of Paul Poberezny Alive" Blum

[Bruce_H]

I too have been dreaming of building an experimental amateur built (EAB) eVTOL similar to the one described in the original post by dapug. I was especially glad for the clarification provided by Joda on the Experimental certification category. But the main stumbling block seemed to me to be the problem of category rating. 14 CFR 61 deals with certification of pilots, and it does list the various categories requiring category ratings. This list (§61.5) includes “Power Lift”. 14 CFR 1.1 defines “Powered-Lift” as:

Powered-lift means a heavier-than-air aircraft capable of vertical takeoff, vertical landing, and low speed flight that depends principally on engine-driven lift devices or engine thrust for lift during these flight regimes and on nonrotating airfoil(s) for lift during horizontal flight.

I believe that this is exactly the aircraft referred to by dapug. But §61.31, which deals with “type rating requirements”, says
(d) Aircraft category, class, and type ratings: Limitations on operating an aircraft as the pilot in command. To serve as the pilot in command of an aircraft, a person must—
(1) Hold the appropriate category, class, and type rating (if a class or type rating is required) for the aircraft to be flown; or
(2) Have received training required by this part that is appropriate to the pilot certification level, aircraft category, class, and type rating (if a class or type rating is required) for the aircraft to be flown, and have received an endorsement for solo flight in that aircraft from an authorized instructor.

This section made me stop thinking about this project. It seemed too daunting to try to get a Powered-Lift category rating—I couldn’t exactly rent time in an Osprey! But this thread made me look a bit deeper, and I think there is a solution. §61.31(l) says:

(l) Exceptions. (1) This section does not require a category and class rating for aircraft not type-certificated as airplanes, rotorcraft, gliders, lighter-than-air aircraft, powered-lifts, powered parachutes, or weight-shift-control aircraft.
(2) The rating limitations of this section do not apply to—
(i) An applicant when taking a practical test given by an examiner;
(ii) The holder of a student pilot certificate;
(iii) The holder of a pilot certificate when operating an aircraft under the authority of—
(A) A provisional type certificate; or
(B) An experimental certificate, unless the operation involves carrying a passenger;
…
(1) seems to say that any non-type-certificated (i.e. experimental) aircraft does not require a category rating.
(2) (iii) (B) reinforces this BUT adds the confusing “unless the operation involves carrying a passenger”. This seems to imply that at least some experimental power lift aircraft (two seaters) would require a category rating. The second paragraph seems to contradict the first.

I would love to hear from someone more well-versed in aviation rules than I. At any rate, it seems that a single seat experimental powered lift aircraft would NOT require a Powered Lift category rating, and possibly a two-seater would be exempt as well.

On a related note, I would love to join a discussion on the technical aspects of experimental Powered Lift aircraft. Are there forums either here in EAA or elsewhere dealing with batteries, motors, thrust, etc?

[Joda]

Bruce,

You have hit the nail on the head, and have illustrated my point about the fact that, until someone actually presents one of these aircraft for certification, we do not know how the FAA will proceed. As you have enumerated, there really isn't any way to get a powered-lift rating without going to work for Boeing or joining the military. So if they decide to go down that route they will need to figure out some path forward. The exemption from a category/class rating for experimental aircraft is indeed found in the regulations, but this is often overtaken by requirements found in the individual aircraft's operating limitations, which are issued as a part of its airworthiness certificate. All currently-issued operating limitations DO carry a requirement for specific category/class ratings appropriate to the aircraft. So that's not a guaranteed solution, and as you mentioned doesn't work as soon as a passenger is introduced.

So we are back to "what will the FAA do". Well, they won't do ANYTHING until they are officially presented with the issue. So all this talk is just that, talk, until someone approaches the FAA with an official application for airworthiness certificate. That's the only way that we will find out what the FAA is going to do about this emerging class of aircraft.

As I've said in my previous posts, stay tuned.

[Bill Berson]

What if a student pilot wants to learn to fly and solo in a EA-B Homebuilt. Is that now impossible because of the limitation?
One of our chapter members built a Flybaby in the 60’S and got some instruction in a two seater and then was signed off to solo the Flybaby without a class or category certificate.
Is that no longer possible?

[Joda]

What if a student pilot wants to learn to fly and solo in a EA-B Homebuilt. Is that now impossible because of the limitation?

The limitations says an instructor's endorsement is also acceptable. Nothing has changed in that regard.

[Bill Berson]

I am still a bit confused about the limitations. 17 and 18 seem to contradict, See below.

As a Private pilot, do I need an instructors endorsement to solo a VTOL? Or do I need to go get another Student certificate?

17. The pilot in command of this aircraft must hold an appropriatecategory/class rating. If required, the pilot in command also must hold atype rating in accordance with FAR 61, or a letter of authorization issued byan FAA Flight Standards Operations Inspector.
NOTE: This limitation applies to any turbojet/turbofan-powered aircraft, anyaircraft with a maximum takeoff weight exceeding 12,500 , or anyother aircraft when deemed necessary.
18. The pilot in command of this aircraft must hold a pilot certificate or anauthorized instructor’s logbook endorsement. The pilot in command alsomust meet the requirements of FAR 61.31(e), (f), (g), (h), (i), and (j), asappropriate.

[Ron Blum]

As Malcolm Gladwell might say, "This thread has reached a Tipping Point".

Although the word "certified" is used interchangeably with the words "type certified", there is a difference between a "certified" airplane and a "type certified" airplane. The pilot requirements pointed out earlier in this thread are for operators of "type certified" airplanes (and "type certificated" to be more technically correct). OEMs (Cessna, Beech, Piper, Cirrus, etc.) play by the exact same regulations as EAB airplanes. Reference 21.19X for these regulations.

The Regulations (CAR3, 14CFR23, etc.) were written for type certification of aircraft … EABs were added later.

Looking at 21.19X, one can see all the different "Experimental" aircraft categories that exist (amateur built, research and development, market survey, show compliance, etc.). So, if one wants to design/build/fly a powered lift to fixed wing vehicle, there is nothing preventing that from happening. What is prevented is carrying "passengers" on an experimental airplane (through operating limitations on an EAB). OEMs have this same restriction on their prototype airplanes (all people on board an experimental airplane must be required flight crew). This is also why EAA has done all the work to get a "second pilot" on board the first flights of an EAB.

If one wants to carry passengers (not required flight crew), they can put the aircraft into experimental "market survey" to be allowed to do so. OR, the restriction can be removed from the operating limitations.

Even OEM-built prototype airplanes play by these same regulations their entire life, … even after the aircraft model is awarded a Type Certification (which does not cover the earlier built prototypes unless the prototypes are brought up the type certification configuration).

Now, if one wants to build these vehicles for commercial service (and/or as a type certificated aircraft) that is a totally different story.

I'm really, really hoping to help (clarify), but this is a very complicated subject.

Bottom line: Just design/build/fly it. There is a way.

Blue on Top,
Ron

[Joda]

I am still a bit confused about the limitations. 17 and 18 seem to contradict, See below.

As a Private pilot, do I need an instructors endorsement to solo a VTOL? Or do I need to go get another Student certificate?

17. The pilot in command of this aircraft must hold an appropriatecategory/class rating. If required, the pilot in command also must hold atype rating in accordance with FAR 61, or a letter of authorization issued byan FAA Flight Standards Operations Inspector.
NOTE: This limitation applies to any turbojet/turbofan-powered aircraft, anyaircraft with a maximum takeoff weight exceeding 12,500 , or anyother aircraft when deemed necessary.
18. The pilot in command of this aircraft must hold a pilot certificate or anauthorized instructor’s logbook endorsement. The pilot in command alsomust meet the requirements of FAR 61.31(e), (f), (g), (h), (i), and (j), asappropriate.

You are quoting limitations from an obsolete version of Order 8130.2. The current version, 8130.2J, contains the following limitation for amateur-built aircraft:

"6. The pilot in command must hold [insert] category and [insert] class certificate or privilege. The pilot in command must hold all required ratings or authorizations and endorsements required by part 61."

The inspector inserts the category and class appropriate to the aircraft being certificated. So in the context of our discussion here, the inspector would have to come up with a category and/or class appropriate to the aircraft. Since we don't know what would be appropriate to the type of aircraft being discussed here, the FAA would have to make a decision at the time of certification. The FAA does have the authority to replace this limitation with something "custom made" to fit the situation. The operating limitations can be modified to fit a particular situation, but only so as more restrictive than the limitations called out in the order. They can not make limitations less restrictive.

Hope this helps!

[Bill Berson]

Regrettably, that doesn't help.
I just want to know if I build an EA-B seaplane or VTOL, can I fly it solo without that appropriate category and class rating?

[Joda]

Regrettably, that doesn't help.
I just want to know if I build an EA-B seaplane or VTOL, can I fly it solo without that appropriate category and class rating?

And the answer would be no, because the operating limitations issued to the aircraft would be the one I quoted in my above post. It would require some sort of category/class rating, at the discretion of the FAA. You have to abide by all regulations AND the operating limitations issued to the aircraft in question. Basically, whichever is the more restrictive of the two is what you go by. Neither one gives you relief from the restrictions of the other.

Hope this helps to answer your question.

[Bill Berson]

Ok then.
It would not be prudent for an individual to invest into something that may or may not be approved in the future.
Back to FAR 103.

[Joda]

It would not be prudent for an individual to invest into something that may or may not be approved in the future.
Back to FAR 103.

It will be approved. Just don't know the details yet. Like any emerging technology, somebody has to take the first steps. It will happen. And when it does, we will know all these answers.

[Bill Berson]

It will be approved. Just don't know the details yet. Like any emerging technology, somebody has to take the first steps. It will happen. And when it does, we will know all these answers.

Are you referring to removing the category and class limitation?
I went through 8130.2j last night and could not find that limitation at all.

[melann]

Are you referring to removing the category and class limitation?
I went through 8130.2j last night and could not find that limitation at all.

That would be in Appendix D, Limitation #7.

[dapug]

Ok then.
It would not be prudent for an individual to invest into something that may or may not be approved in the future.
Back to FAR 103.


It will be approved. Just don't know the details yet. Like any emerging technology, somebody has to take the first steps. It will happen. And when it does, we will know all these answers.

Here we have the chicken/egg problem. A statement in my OP which I reemphasize here is:
"Experimental innovations in this area are completely stifled if we (the builders and pilots) do not know how our efforts (of building something with the intent to fly) will be allowed and governed in the end."

It may be asking for too much. I completely understand the perspective to build it first, regs come later. This is how Part 103 came about. But the investment to build eVTOL is surely far more than building a FAR 103 UL. Commercial investors (I heard there are over 200 companies now pushing their eVTOL ideas) can manage this risk because many of them are simultaneously working with FAA to identify the needed changes, and are backed by VERY deep pockets (such as founders of Google, etc).

Our options seem to be:


Build it now and hope for the best
Don't build until new FAA regs present themselves, the commercial folks paving the way (bearing in mind, they don't have the needs of home builders in mind)


I don't like either of these options. I would think my membership in EAA means that EAA can work on this on my behalf and be a voice for the experimental/home builders in this space. That is the effort I'd like to spark.

In the meantime, I'm seriously considering option 1 right now.


Dapug: YOU ARE EXACTLY THE PERSON WE NEED! (and I'm very serious about that.)

Design it, Build it and Fly it as an EAB!


I would love to join a discussion on the technical aspects of experimental Powered Lift aircraft. Are there forums either here in EAA or elsewhere dealing with batteries, motors, thrust, etc?

If I get into this, I won't go solo. I've begun setting up an Open Source strategy to get eVTOL into the hands and on the scene of experimental/home builders. A bigger question than just where to get info about batteries/motors is this: would there be enough interest by educated engineers to dive into a community project like this? That question is a topic for another thread. But the legalities here do still weigh heavily on my mind.

[Bill Berson]

That would be in Appendix D, Limitation #7.

Hi Mel,
I did look at Appendix D, Limitation #7 last night. #7 appears to be for Part 21.190 and 21.191. But there is no code (g) so does not apply? (code g is the sub-paragraph from 21.191 (g) which is for EA-B, I think)

Joe said Limitation #6 in a previous post. Makes me wonder if this has recently changed? Also, what does Joe (Joda) imply when he said "stay tuned" several times. (does that mean wait time is three months, three years or what?)

























7
190 & 191AFS-800
All single seat,hot-air airshipssuch as theThunder & ColtAS-56
The PIC must hold a pilot certificate with a lighter-than-air category ratingand an airborne heater privilege. The PIC must hold all required ratingsor authorization and endorsements required by 14 CFR part 61. (7)


For atypicalaircraft,coordinate withAFS-800.
The pilot in command must hold _________ category and ______ classcertificate or privilege. The pilot in command must hold all requiredratings or authorizations and endorsements required by part 61. (7)



























Note, I edited this post to include "code g" information after additional review of 8130.2j Appendix D-4

[melann]

You will not find a "list" that will automatically apply. The inspector must pick which limitations apply to the particular aircraft. Limitation 7 is divided between single seat, hot-air airships and atypical aircraft. The first obviously applies only to single seat hot-air. The second applies to other aircraft under part 190 & 191. Amateur-built aircraft fall under 191(g), so the second wording applies unless it is a single seat hot-air airship.

As far as Joe's comment about paragraph 6, he may be referring to paragraph 6 in his particular Operating Limitations. Limitation 7 will not always be Paragraph 7.

Limitation 6 applies to part 190, which is Special Light-Sport aircraft.

[robert l]

Here we have the chicken/egg problem. A statement in my OP which I reemphasize here is:
"Experimental innovations in this area are completely stifled if we (the builders and pilots) do not know how our efforts (of building something with the intent to fly) will be allowed and governed in the end."

It may be asking for too much. I completely understand the perspective to build it first, regs come later. This is how Part 103 came about. But the investment to build eVTOL is surely far more than building a FAR 103 UL. Commercial investors (I heard there are over 200 companies now pushing their eVTOL ideas) can manage this risk because many of them are simultaneously working with FAA to identify the needed changes, and are backed by VERY deep pockets (such as founders of Google, etc).

Our options seem to be:


Build it now and hope for the best
Don't build until new FAA regs present themselves, the commercial folks paving the way (bearing in mind, they don't have the needs of home builders in mind)


I don't like either of these options. I would think my membership in EAA means that EAA can work on this on my behalf and be a voice for the experimental/home builders in this space. That is the effort I'd like to spark.

In the meantime, I'm seriously considering option 1 right now.





If I get into this, I won't go solo. I've begun setting up an Open Source strategy to get eVTOL into the hands and on the scene of experimental/home builders. A bigger question than just where to get info about batteries/motors is this: would there be enough interest by educated engineers to dive into a community project like this? That question is a topic for another thread. But the legalities here do still weigh heavily on my mind.

If it's something you really want to pursue, and you can afford it, or get investors, Option # 1. At the very least, you'll have something nobody else has !
Bob

[Bill Berson]

Thanks Mel, I figured I could just go down the list looking for all the 191(g) that apply to EA-B.
But #7 does not have the 191(g).
Would the inspector insert the #7 limitation anyway for a normal EA-B? Or are you only talking about an unusual VTOL for inserting limitation #7?

[melann]

Thanks Mel, I figured I could just go down the list looking for all the 191(g) that apply to EA-B.
But #7 does not have the 191(g).
Would the inspector insert the #7 limitation anyway for a normal EA-B? Or are you only talking about an unusual VTOL for inserting limitation #7?

When it has the 191 and not the 191(g), that means it applies to all 191. It's actually §21.191(a) is R&D, §21.191(b) is Show Compliance, §21.191(c) is Crew Training, §21.191(d) is Exhibition, ........through §21.191(i) which is Experimental Light-Sport.

Limitation 7 applies to all E-AB. i.e. All §21.191 aircraft. For an unusual VTOL (atypical) the inspector needs to coordinate with AFS-800 in Oklahoma City.

[Bill Berson]

When it has the 191 and not the 191(g), that means it applies to all 191. It's actually §21.191(a) is R&D, §21.191(b) is Show Compliance, §21.191(c) is Crew Training, §21.191(d) is Exhibition, ........through §21.191(i) which is Experimental Light-Sport.

Limitation 7 applies to all E-AB. i.e. All §21.191 aircraft. For an unusual VTOL (atypical) the inspector needs to coordinate with AFS-800 in Oklahoma City.

Thank you. I hope that is all for now. I will stay tuned.

[Ron Blum]

I completely understand the perspective to build it first, regs come later.

Our options seem to be:


Build it now and hope for the best.

In the meantime, I'm seriously considering option 1 right now.

I've begun setting up an Open Source strategy to get eVTOL into the hands and on the scene of experimental/home builders. A bigger question than just where to get info about batteries/motors is this: would there be enough interest by educated engineers to dive into a community project like this? That question is a topic for another thread.

Regulations come later (mainly for type certificated airplanes) because regulations can't be made for aircraft/configurations we don't know about.

Option 1 is the only choice currently.

Open Source - and here begins the problem. The reason so many entities (200+) are designing eVTOL vehicles is potential profit to the winner(s). The hope for thousands and thousands of vehicles and billions and billions of dollars of profit. And this leads directly to my next point (and, yes, it should be a different thread).

I would consider myself to be one of the "educated engineers" mentioned above. Of course I would love to be involved in a project like this, but … I need to eat, and I have house, medical and car payments to make. As for getting information from OEMs on batteries and motors, this same logic applies. They could give all their information to open-source groups (and go out of business due to lack of profits) or they can attempt to stay in business by selling their goods/information.

I believe your best bet is like EAB people before you have successfully accomplished is to use what is currently, commercially, available for your project. In other words, many of the early EAB airplanes had automotive engines in them (Fords, VWs, Chevys, etc.). There are a lot of Tesla wrecks out there. Systems from Zero motorcycles are being used to convert airplanes to electric, too. The possibilities are endless!

Ron "More than my two cents" Blum

[dapug]

...
Open Source - and here begins the problem.
...
I would consider myself to be one of the "educated engineers" mentioned above. Of course I would love to be involved in a project like this, but … I need to eat, and I have house, medical and car payments to make.
...


Sounds familiar Ron. I'm a Microsoft engineer from the 90's and 2000's, the era where Open Source was viewed exactly as you described, and I despised it because I have a family to feed.

"Free work" is STUPID. So why would I think open source is a good route now?

Two things I've since learned about open source (done RIGHT):


It is profitable, just a different business model behind it.
It is career building (make a name for yourself)


In the software world, the most "famous" and highly paid engineers are often ones that started (and often continue) in open source, when the thing they built for the world becomes so popular and critical, and EVERYONE wants to hire them. That addresses #2 point above. But also leads to point #1. A few business models that work are as a consultancy (now that you made a name for yourself), or as a support or service (this is how AWS Amazon Web Services makes billions, providing a service built on top of open source linux), or through licensing of the thing you created. There are other really creative business models too, but I'll stop there.

Now let's apply this to aviation.

People with an established career may not care about #2. They will either balk at this and not participate, OR they will need to be compelled by a business model that would work and they can be a part of. The way I see it, if an open source design becomes popular and sought after by a segment of the community/market, then there are TONS of opportunities to put a business in place, either licensing the design to a manufacturer, or by getting into the kit building biz, etc. Remember, this isn't the 70's or 80's anymore. Plans-built is dead. ~98% of people out there don't want to scratch build, even if plans are FREE. Therefore the $ is not in the design anyway... might as well make it open! Make sense? The $ is elsewhere, and that $ would belong to any contributor to the plans. This is the model I am working on.

I agree completely regarding the use of available components (Zero as you mentioned, etc). I'm not trying to invent motors here, I'm trying to come up with a practical horizontal flight eVTOL airplane buildable by home builders with commercially available parts. How many motors? Will the wings rotate, or stay fixed? How will it transition? Should it be a hybrid, or all electric? That takes engineering, and a Tesla junkyard is not going to provide it.

Lastly, I think it would be pretty cool to see community designed planes. A revolution and shift is indisputably happening in aviation regarding eVTOL. Let's also see a shift in the way planes get designed in the first place too.

[Bill Berson]

The current FAR that exempts experimental from the category and class rating is the law. I don't see how any FAA Order can overtake the Federal Aviation Regulation that went through the full public process.
I think pilots are only required to read and follow the FAR's.
This should be challenged with a court case if it hasn't happened already.

[Airmutt]

A bit off topic but...

FAA orders, notices and bulletins are documents that provide information to FAA employees. These documents are essential sources of information on what the FAA expects of applicants and certificate holders. Most of these documents can be obtained on the FAA’s regulatory and guidance library (http://rgl.faa.gov/).
An order is considered an “internal agency mandate”. It is issued by the agency, to agency staff to explain a position on a specific question not directly addressed by a statute or regulation. Orders, like other non-legislative rules (e.g., ACs, notices, general statements of policy), are not created under delegated authority from Congress and most do not have to go through notice and comment under the APA.
Orders are meant to be binding (or provide direction) only to FAA employees, and not the public at large. However, if an inspector feels bound to act in a particular way because of direction in the “handbook”, that decision has real practical effect to those subject to FAA regulation. Therefore, internal government documents cannot be contrary to the plain language of the regulation or any clarification in the agency’s preamble to the rule.

[Bill Berson]

A bit off topic but...

FAA orders, notices and bulletins are documents that provide information to FAA employees. These documents are essential sources of information on what the FAA expects of applicants and certificate holders. Most of these documents can be obtained on the FAA’s regulatory and guidance library (http://rgl.faa.gov/).
An order is considered an “internal agency mandate”. It is issued by the agency, to agency staff to explain a position on a specific question not directly addressed by a statute or regulation. Orders, like other non-legislative rules (e.g., ACs, notices, general statements of policy), are not created under delegated authority from Congress and most do not have to go through notice and comment under the APA.
Orders are meant to be binding (or provide direction) only to FAA employees, and not the public at large. However, if an inspector feels bound to act in a particular way because of direction in the “handbook”, that decision has real practical effect to those subject to FAA regulation. Therefore, internal government documents cannot be contrary to the plain language of the regulation or any clarification in the agency’s preamble to the rule.

That is exactly on topic Dave.
That says an internal document cannot be contrary to the plain language of the regulation. And 14CFR Part 61.31(k) (2) (B) is clearly plain language, as I see it. Thanks.

[CHICAGORANDY]

"I personally am not interested in "manned drone", but rather, horizontal "fixed" wing flight with VTOL ability."


So... you want to make an EAB Harrier, but powered by electric motors. Get out the foam, balsa and epoxy and go for it. Send pics of the construction progress. Start with a scale RC craft and take it from there. What's the problem? Other than needing a regulation size dump truck full of $100 bills to fund it of course - lol

[skyfixer8]

In reading all in this discussion, and watching a few videos with music to sleep by while a manned drone flies off with a beautiful model apparently at the controls, I have to ask a question. While building these toys, if certification happens, will the FAA look at engine out performance, glide ratio ( haven t seen one yet with anything to glide on), how about stall spin characteristics ? Is it gonna have a Cirrus type recovery chute ? Yes, new designs will come out, but when you are "killing clouds" and something goes wrong, what will happen ? Sorry, but as a pilot with experiences in the above, gotta ask the question.

Bill Landry

[rwanttaja]

In reading all in this discussion, and watching a few videos with music to sleep by while a manned drone flies off with a beautiful model apparently at the controls, I have to ask a question. While building these toys, if certification happens, will the FAA look at engine out performance, glide ratio ( haven t seen one yet with anything to glide on), how about stall spin characteristics ? Is it gonna have a Cirrus type recovery chute ? Yes, new designs will come out, but when you are "killing clouds" and something goes wrong, what will happen ? Sorry, but as a pilot with experiences in the above, gotta ask the question.
*If* one of these doo-hickeys is ever certified, you can bet the FAA will require some sort of fallback to keep single-string powerplant failures from causing major injuries. If you've got a man-carrying quad-copter, and failure of one motor or rotor puts the thing into an uncontrollable tumble, the FAA isn't going to buy off on it.

It may be an auto-deployed ballistic chute, or it may be (as others have suggested) a degraded-operations mode that allows a safe landing. The latter, for instance, might cut the other side's motor in the case of a motor/rotor failure on a quad-copter, and an overspeed mode on the remaining two that deposits the vehicle on the ground at a reasonable descent rate.

If helicopters couldn't autorotate, the FAA never would have allowed their certification. However, pilots must usually keep to a specific profile to enable safe autorotation...
http://www.copters.com/pilot/pictures/R22HV.gif
It would be assumed that these new powered-lift devices would hard-code such profiles so that their operators stay within them.

Ron Wanttaja

[skyfixer8]

Ron, I understand helicopters can auto rotate, but the blades on these toys would have to be a lot bigger like a helicopters to develop any lift .

Bill Landry

[rwanttaja]

Ron, I understand helicopters can auto rotate, but the blades on these toys would have to be a lot bigger like a helicopters to develop any lift .
Yes, I know, but the FAA will require a certified powered-lift vehicle to provide equivalent capability...either in the form of a chute, or in a degradation mode. The helicopter HV diagram above was just showing that conventional rotorcraft have bad corners, too.

Ron Wanttaja

[Ron Blum]

New vehicles will have to go through what is now being referred to as "graceful degredation". Earlier Part 23 is "No single failure can be catastrophic." Graceful degredation takes this another step forward with something like: "After a failure, the vehicle must be able to continue safe flight to a landing." Not saying it's not possible, but I don't see a quadcopter being FAA certificable ... hex, octo, etc. is possible.

Just as a note, the current whole aircraft parachutes are not 0/0 chutes. 0/0 chutes are expensive, heavy and impart high loads on the vehicle and its occupants.

[Ron Blum]

Now let's apply this to aviation.

I agree completely regarding the use of available components (Zero as you mentioned, etc). I'm not trying to invent motors here, I'm trying to come up with a practical horizontal flight eVTOL airplane buildable by home builders with commercially available parts. How many motors? Will the wings rotate, or stay fixed? How will it transition? Should it be a hybrid, or all electric? That takes engineering, and a Tesla junkyard is not going to provide it.

A revolution and shift is indisputably happening in aviation regarding eVTOL. Let's also see a shift in the way planes get designed in the first place too.

I'm still listening but not YET convinced.

There already has been a huge revolution and shift in aviation! Look at the $1.4B that Eclipse wasted on an unfounded, pie in the sky, business model. Now the question is how many more $B or even $T are going to be wasted ignoring basic physics? Just briefly (free Engineering advice :), there is currently not a high enough power/weight ratio with electric/electric storage for long, fast flights in conventional, fixed wing aircraft. Now add to this, power-lift vehicles require ~10 times more thrust than fixed wing aircraft. Decreasing the rotor diameter makes this much worse … and adds noise. For those not old enough or haven't done their homework (those that don't know history are bound to repeat it), all of these new revolutions have been done before! Powered lift, ducted fans, blown wings, VTOL (tilt wing, tilt rotor, tilt pod, tilt etc.), boundary layer suction, etc. In the end on (e)VTOL, they are greatly speed limited due to no propeller inflow velocity for takeoff and a lot of inflow velocity for cruise. With this said, though …

We do need to be getting ready for when electric power will be truly unlimited. Electric airplanes have HUGE advantages in many areas. The simplest being that a single-engine airplane can be made into a "multi-engine" airplane with a single motor (2 or more motors within 1 physical motor). Electricity simplifies many, many areas. I'm all for electrics and getting ready for the future. The future is not just thousands and thousands of autonomous, intercity vehicles that reduce automobile congestion instantly by 2021.

If you want to develop a kick *, electrically-powered, conventional airplane that is more reliable, safer and the currently-foreseeable future, I'd be thrilled to make you/us rich. :)

Blue on Top,
Ron Blum

PS. (More free engineering) Hybrid related to airplanes is NOT more efficient, it is an interim fix until we solve the energy density issue first.

[Joda]

The current FAR that exempts experimental from the category and class rating is the law. I don't see how any FAA Order can overtake the Federal Aviation Regulation that went through the full public process.
I think pilots are only required to read and follow the FAR's.
This should be challenged with a court case if it hasn't happened already.

Bill,

You can't just hold out one regulation and hang your hat on it to the exclusion of the whole of the regulations. While Part 61 does indeed include an exclusion that would permit a pilot to operate an aircraft that holds an experimental airworthiness certificate without an appropriate category/class rating (when no passengers are carried), there is more to the story. The aircraft must be operated in accordance with the regulations found in other parts of title 14, as appropriate. Specifically in this case, 91.319. Among other operating limitations applicable to experimental aircraft, 91.319 contains the following regulation:

"(i) The Administrator may prescribe additional limitations that the Administrator considers necessary, including limitations on the persons that may be carried in the aircraft."

This points out that additional operating limitations are issued for these aircraft. The operating limitations are issues as a part of the individual aircraft's airworthiness certificate. An aircraft issued an airworthiness certificate at the current time would include an operating limitation I quoted earlier in this thread that would specify what category/class rating is required in order to act as PIC of that particular aircraft.

So the ability for the FAA to issue such an operating limitation is already found in the regulations. No "overtaking" is happening. The operating limitations are issued in accordance with the regulations. The part 61 regulation you refer to is there to allow the FAA to be flexible in issuing said operating limitations when the need arises. The case we are discussing in this thread may very well be one of those cases. But until someone actually presents such a vehicle for certification, all this discussion is merely conjecture. We just don't know at this point what the FAA might do. As soon as someone steps up to the plate and submits an actual application for an airworthiness certificate, we will find the answers.

[Bill Berson]

Bill,

You can't just hold out one regulation and hang your hat on it to the exclusion of the whole of the regulations. While Part 61 does indeed include an exclusion that would permit a pilot to operate an aircraft that holds an experimental airworthiness certificate without an appropriate category/class rating (when no passengers are carried), there is more to the story. The aircraft must be operated in accordance with the regulations found in other parts of title 14, as appropriate. Specifically in this case, 91.319. Among other operating limitations applicable to experimental aircraft, 91.319 contains the following regulation:

"(i) The Administrator may prescribe additional limitations that the Administrator considers necessary, including limitations on the persons that may be carried in the aircraft."

This points out that additional operating limitations are issued for these aircraft. The operating limitations are issues as a part of the individual aircraft's airworthiness certificate. An aircraft issued an airworthiness certificate at the current time would include an operating limitation I quoted earlier in this thread that would specify what category/class rating is required in order to act as PIC of that particular aircraft.

So the ability for the FAA to issue such an operating limitation is already found in the regulations. No "overtaking" is happening. The operating limitations are issued in accordance with the regulations. The part 61 regulation you refer to is there to allow the FAA to be flexible in issuing said operating limitations when the need arises. The case we are discussing in this thread may very well be one of those cases. But until someone actually presents such a vehicle for certification, all this discussion is merely conjecture. We just don't know at this point what the FAA might do. As soon as someone steps up to the plate and submits an actual application for an airworthiness certificate, we will find the answers.

Joe,
I am still confused about post #13 where you said a student pilot can solo an EA-B with an instructors endorsement.
But then in post #18 you said to me: as a Private Pilot I would need a category and class rating. Why can't a private pilot fly solo with only an instructors endorsement instead of a category and class rating?

I see the current limitation has "must hold category and class certificate or privilege. ​What is privilege?

[Joda]

Joe,
I am still confused about post #13 where you said a student pilot can solo an EA-B with an instructors endorsement.
But then in post #18 you said to me: as a Private Pilot I would need a category and class rating. Why can't a private pilot fly solo with only an instructors endorsement instead of a category and class rating?

I see the current limitation has "must hold category and class certificate or privilege. ​What is privilege?

An instructors endorsement is a "privilege" for the purposes of this operating limitation. This allows a sport pilot to fly the aircraft on the sport pilot endorsement (assuming the aircraft is sport pilot-eligible), as well as a student pilot if an instructor is willing to endorse the student to solo the experimental aircraft.

[Bill Berson]

An instructors endorsement is a "privilege" for the purposes of this operating limitation. This allows a sport pilot to fly the aircraft on the sport pilot endorsement (assuming the aircraft is sport pilot-eligible), as well as a student pilot if an instructor is willing to endorse the student to solo the experimental aircraft.

That's good to know in advance. I have an unfinished Avid Amphibian that can be certified either two or three seats. I will choose two seats at the time of application so it qualifies as Light Sport. Won't need the seaplane category and class add on rating at all,apparently. Just a seaplane light sport endorsement. Thanks.

Back to thread topic, I don't know if "Light Sport Powered Lift" is possible. I know Light Sport Helicopter isn't. Perhaps that is part of the "stay tuned".

[Joda]

I don't know if "Light Sport Powered Lift" is possible. I know Light Sport Helicopter isn't. Perhaps that is part of the "stay tuned".


Powered lift is specifically excluded in the definition of a light-sport aircraft. Check FAR 1.1 for reference.

[Bill Berson]

It seems to me, the experimental- research and development (testing of new design concepts), is the way to go.
From the current 8139.2j, MIDO is the place to go. Maybe they could issue an appropriate variance with operating limitations that protect the public but not require a powered lift rating for the test pilot.

[Joda]

It seems to me, the experimental- research and development (testing of new design concepts), is the way to go.
From the current 8139.2j, MIDO is the place to go. Maybe they could issue an appropriate variance with operating limitations that protect the public but not require a powered lift rating for the test pilot.

Bill,

Experimental R&D is a valid option, but not as desirable because the airworthiness certificate is limited-duration. Typically these are only issued for 6 months or less, in order to prove a concept or gain approval for a modification. This in fact might be the way the FAA would go initially with an aircraft such as we are discussing here. Might do an R&D certificate for a limited time, then later switch it to amateur-built or exhibition as appropriate. This would allow them to sort out the pilot requirements in a very controlled condition before issuing broader operating limitations.

[Bill Berson]

Getting an airworthiness certificate should be readily achievable. Then the question turns back to how does the FAA expect an experimenter to get a powered lift endorsement or authorization to test fly?

[dapug]

Hey everyone. I found a single article that answers almost every question I had - basically outlines the entire journey that one would embark on (as it stands today) to achieve what I originally posted about.

Check this out:
https://www.verticalmag.com/news/evtol-test-pilot-perspective/

Here is a summary as it relates to the conversation in this thread.

Aircraft points of interest:

Configuration/type of experimental: A heavily modified Lancair with eVTOL ability. (horizontal flight, not simply a "manned drone")
Not autonomous (so far wasn't the goal of this particular aircraft) - pilot required
Not hype. 180+ manned flights, unlike most of the rest of the entire eVTOL industry to date, still doing unmanned testing.
Unique aircraft design is optional. Lancair is a well-known well-loved kit aircraft for horizontal flight. Engineering efforts then focused around VTOL specifically.
Redundancy - can have a motor out, or battery outage, and it still flies (still does NOT meet the requirement not to stall when unpowered)

This was tested while manned! (whoa)



Pilot points of interest:


Pilot is rotorcraft certified (was a pilot, but then got trained to fly heli)
FAA granted Powered Lift rating to the pilot! (without military tiltlift training)


^ So far, this seems to be the pilot requirement for anything experimental VTOL that is not autonomous, and is NOT easy to arrange (must convince FAA) ^

Development points of interest:


X-Plane creator Austin Meyers directly assisted development via add-ons for tests to run in the Simulator before actual flight tests (that's freakin awesome)
Beta Technologies now has an approved, simulator-based training program that will allow it to sign off additional powered lift test pilots (also super freakin awesome)


That pretty much answers all sorts of curiosities on this topic. Granted, it's not at the level of low-budget home building, but we can see what it would take for any builder/entrepreneur to push the bleeding edge on the eVTOL front. And it doesn't yet answer how the aircraft itself will be classified when done. I'm a little bummed, as I definitely am not interested in heli training, so I guess I'll be waiting for the far distant future when a new pilot cert is perhaps created. In the meantime, that eVTOL X-Plane sim training would be AWESOME if they could make that available to us all.

Coolest quote, regarding the lack of rotor spinning due to the nature of electric instant on/off of the rotors:
"...it also caused some confusion for a tower controller who was clearing Clark for a 10-minute hover test. “They kept asking me if I was ready to go because they didn’t see any rotors turning . . . I said, ‘Absolutely, I’m ready to go.’ And they’re like, ‘Advise when you are ready to go.'”"

[Bill Berson]

Excellent article, thanks.
I was flying a small RC evtol today, almost exactly like that Clark "Ava" configuration in the article. The model was easy to fly and transition to forward flight.
So I don't see how my previous RC helicopter or full scale helicopter flight time would help at all much. The automation is essentially keeping these things upright and stable. Unlike the piston helicopters I flew, that require the pilot do everything including constant engine/rotor rpm control. But this automation reliability scares me. I would want a pilot take over control capability.

I hope he stops at Air Venture on his transamerica flight.
For my experiments, it would need to be much, much smaller and lighter, cheaper.

[dapug]

...I was flying a small RC evtol today, almost exactly like that Clark "Ava" configuration in the article. The model was easy to fly and transition to forward flight.


Do tell. Is this your design or is there an RC community that has come up with some concepts or plans?


...this automation reliability scares me. I would want a pilot take over control capability.


Makes sense, but I'm just not seeing how it would be possible. I think just taking comfort in knowing (and requiring) redundancy of all parts of the powertrain from sensor/controllers to power to motor is the best option.

I've done some coding on these microprocessors like we see in RC quad copters, and self balancing robots (like segway, etc). They have to "think" way faster than the human mind, or human reaction time. That is pretty much required for proper balance here. It really isn't possible for human perception to step in and handle the stabilization control. I for one do not view this as "auto-pilot" or automating the pilots responsibility. The human mind needs to focus on other things (flying, maneuvers, situational awareness, etc) than merely stability that can be left wholly to a computer.

Now as for fully autonomous piloting, navigation, maneuvers... I couldn't agree more, I would want a pilot on board! It will be a loooong time before I can accept fully autonomous flight, or driving.

[Bill Berson]

I was flying this thing yesterday https://m.youtube.com/watch?v=CGN3LcosLZ4
My friend brought it to the RC field. He said it was $100 but can be found for $50.

I like the idea of a fully flyable glider when all the powered lift systems fail for whatever reason. The problem is getting to and from that safe glide height.

[dapug]

I like the idea of a fully flyable glider when all the powered lift systems fail for whatever reason. The problem is getting to and from that safe glide height.

Exactly my thoughts!

[Bruce_H]

I have learned a lot from this thread, and I am "cautiously optimistic". But back to the intent of the Original Poster: can we get some sort of "preliminary approval" from FAA? Several posts, mostly from Joda, say "build it and see what happens". But it would be a shame to make the investment in time and money only to discover that we wouldn't be allowed to fly our aircraft. Several contributors, including Joe and Mel, are DAR's. If YOU were presented with an aircraft like originally described (I will describe my concept aircraft in more detail below, but wanted to get this question at the top of the post), as a DAR, would you feel compelled to include a requirement for Power Lift category rating in the Operating Limitations? Or is there some possibility of a work-around? Is it possible to put this question to the FAA, prior to actual building? (As DAR's, you are the FAA, sort of).

As for my concept aircraft, I would hope to start with a proven airframe, probably ultralight in nature, such as a Quicksilver. I would like to begin with a kit, to allow airframe modifications as necessary, and to avoid any questions about the 51% rule. I would add lift-and-control motors to nose, tail, and each wingtip, with these motors providing about half the lift needed for hovering, and pitch, roll, and yaw control while hovering. I plan on 8 of these motors total, two at each location, with sufficient lift to provide single-motor failure hover capability. I would add 4 tilting "main" motors on an axis near the CG, close to the fuselage. These motors would provide the other half of the hovering lift, and all of the forward flight thrust. During forward flight, the lift-and-control motors would be deactivated, and the aircraft would be flown in standard three-axis control mode. In the event of a major failure, such as a total battery failure, the aircraft would be glided to a landing, the same as the reaction to an engine failure in a conventional single engine aircraft.

[Joda]

If YOU were presented with an aircraft like originally described (I will describe my concept aircraft in more detail below, but wanted to get this question at the top of the post), as a DAR, would you feel compelled to include a requirement for Power Lift category rating in the Operating Limitations? Or is there some possibility of a work-around? Is it possible to put this question to the FAA, prior to actual building? (As DAR's, you are the FAA, sort of).

I thought I described the process before, but just in case.... I, as a DAR, would not be able to make any specific determinations on my own. I would present the application to my FAA advisor, and he would work it through the system. I would not feel "compelled" to recommend ANY particular pilot qualifications. I would open a dialog with my FAA office and we would work the application. In a unique situation such as you describe, I am confident that my FAA guy would in turn talk to his manager, and they in turn would forward the application up the chain to wherever it would need to go for a final determination.

Unfortunately, this gets us back to the "chicken and egg" thing. That is, I could not make ANY request for determination on this issue UNTIL I had an airworthiness application in hand. Anything that would be discussed before an application was presented would be non-binding by all parties.

In any case, your investment wouldn't be lost. The aircraft would ultimately be certificated. We just don't know what the pilot requirements would be at this time.

Sorry I don't have better news, but that's the state of affairs as it stands.

[Jyrodyne]

I've been working on VTOL homebuilts for over 20 years, and have expiring patents on one. The advances in cheap controls and much more powerful electric motors drive a lot of the new developments, of course. However, I think Eric Lindbergh and his crew working on hybrid aircraft understand the crux of the problem. I'm a chemical engineer, and worked a lot in electrochemistry and energy technology before retiring. The energy density of current battery technology is not too far from reaching its theoretical limit on voltage per cell, which is about 5 volts. Using lithium has reduced the coulombs per pound to a minimum, too. Power density should continue to improve, with state of the art $ 2 MM hypercars using 150 pound batteries the size of a sofa cushion which can put out nearly 2000 hp. But not for very long! So electric systems can produce the huge VTOL lift power to get off, but the range will always be very limited, particularly for the designs which don't use wings. So the most reasonable solutions, in my opinion, will use electric motors for a short time to assist with takeoff, and then depend on an efficient combination of wings and internal combustion engines for cruise flight. None of these electrics will be able to have a long loiter time under VTOL conditions.

There are an enormous number of developing eVTOL designs out there, as could be seen in the Innovations Tent at Airventure this year. The Boeing GoFly contest has brought everybody out, although I think the 8' cube volume restriction will limit the viability of the winning design. There is also an awful lot of money being poured into these designs, at last count hundreds of millions of dollars, which range from outright crazy to what look like very workable designs. Reminds me of the early days of MS-DOS and PCs. All of these things will be coming out of the woodwork long before any of us could start something from scratch, based on how long it takes homebuilders to complete their airplanes! I'm as guilty as any, with me and my partners taking nearly a decade to get a RANS S6 flying. Of course, maybe some of them will consider the kit route...........

Anyone who would like to read up on the theory of lithium batteries and their limitations, drop me a line and I'll send you a copy of the article, which can be found in the archives of Chemical Engineering Progress, the flagship publication of the American Institute of Chemical Engineers. You can reach me at jyrodyne@comcast.net.

Charlie Churchman, P.E.