A hybrid electric STOL plane

[MountainDude]

First manned flight. Looks very interesting.
Has an engine (I think a turbine, but not sure) to produce the electricity for the battery and electric motors:

Electra Achieves Takeoff, Landing With Under 170 Feet of Runway

The ability to take off and land using soccer field-sized spaces is the calling card of Electra’s eSTOL, which demonstrates the capability for the first time.

www.flyingmag.com

 

[gearFX]

Thanks for sharing, performance looks good in the video.

 

[tspear]

That is impressive. And does not appear to depend on some magical new battery tech either.

 

[Bell206]

Has an engine (I think a turbine, but not sure) to produce the electricity for the battery and electric motors:

It uses an existing turbine APU to generate the power. Given they're more conventional, the eSTOLs are on the opposite side of the scale from eVTOLs as most eSTOLs are pursuing Part 23 certification. There is also a larger interest from the military side for eSTOLs which Electra has benefited from. I believe the full size production demonstrator is scheduled to fly next year with a larger purpose built APU and will supposedly run on 100% SAF.

 

[MountainDude]

It uses an existing turbine APU to generate the power. Given they're more conventional, the eSTOLs are on the opposite side of the scale from eVTOLs as most eSTOLs are pursuing Part 23 certification. There is also a larger interest from the military side for eSTOLs which Electra has benefited from. I believe the full size production demonstrator is scheduled to fly next year with a larger purpose built APU and will supposedly run on 100% SAF.

Thank you.
I wonder if someone can make this for GA, where the turbine is replaced with an ICE engine (a small Rotax, for example)?
It should be safer, since electric motors rarely fail and the battery is there to get you to an airport if the ICE engine fails.
It should be cheaper to maintain, since the ICE engine would be smaller and always run at its optimal performance.

 

[MountainDude]

It uses an existing turbine APU to generate the power. Given they're more conventional, the eSTOLs are on the opposite side of the scale from eVTOLs as most eSTOLs are pursuing Part 23 certification. There is also a larger interest from the military side for eSTOLs which Electra has benefited from. I believe the full size production demonstrator is scheduled to fly next year with a larger purpose built APU and will supposedly run on 100% SAF.

Also, the APU sounds like a turboshaft engine connected to a generator, correct? That means it's as expensive as a turbine engine.

 

[Bell206]

the APU sounds like a turboshaft engine connected to a generator, correct? That means it's as expensive as a turbine engine.

Yes. But no on the costs. At best an APU is merely built under a TSO, i.e., its not certified like a turbine engine. For example, you can find older T-62 APUs for less than $20,000.

I wonder if someone can make this for GA, where the turbine is replaced with an ICE engine (a small Rotax, for example)?

While I'm sure its possible, I doubt it will perform as well as a turbine APU. And these APUs tend to be smaller than you think and come in various sizes. The T-62 mentioned above is used in some E/AB helicopters like a Helicycle pic'd below.

I'm not 100% positive but I think the Electra eSTOL you linked actually used a modified 172 wing for their prototype so it seems they're halfway to getting it in a GA aircraft.

 

[MountainDude]

Yes. But no on the costs. At best an APU is merely built under a TSO, i.e., its not certified like a turbine engine. For example, you can find older T-62 APUs for less than $20,000.

While I'm sure its possible, I doubt it will perform as well as a turbine APU. And these APUs tend to be smaller than you think and come in various sizes. The T-62 mentioned above is used in some E/AB helicopters like a Helicycle pic'd below.

I'm not 100% positive but I think the Electra eSTOL you linked actually used a modified 172 wing for their prototype so it seems they're halfway to getting it in a GA aircraft.

View attachment 129348

Thank you.
Are you saying that they could put an uncertified engine (the APU) into a certified plane because it does not directly provide the power to the electric motors?
Also, my understanding is that a turbine engine costs several $100Ks. Why is the uncertified APU so cheap ($20K)?

 

[Velocity173]

I don’t think they understand that the requirement for a 0 ft take off / landing is a real thing. 90 % of my operations are that. 300 ft is searching for a requirement that generally doesn’t exist.

 

[tspear]

I don’t think they understand that the requirement for a 0 ft take off / landing is a real thing. 90 % of my operations are that. 300 ft is searching for a requirement that generally doesn’t exist.

Depends on the mission. I doubt this would appeal to anyone to replace EMS helicopters. With EMS, you need the VTOL not STOL.
However, it does open up a lot of additional locations for potential landing/takeoff locations. e.g. instead of requiring an airport with a 3K runway, you can now convert part of a parking lot to a runway, with a portable trailer for the FBO. I have seen all sorts of semi-random locations turned into bus stops. Why not apply the same logic to small moveable "airports".

The only use case I have thought of, and not saying this is the only use case. I think this would have a lot more appeal actually for back country and to carry larger loads than a C206 could carry into remote lodges. Otherwise, I am kinda curious on the proposed business model.

Tim

 

[Velocity173]

Depends on the mission. I doubt this would appeal to anyone to replace EMS helicopters. With EMS, you need the VTOL not STOL.
However, it does open up a lot of additional locations for potential landing/takeoff locations. e.g. instead of requiring an airport with a 3K runway, you can now convert part of a parking lot to a runway, with a portable trailer for the FBO. I have seen all sorts of semi-random locations turned into bus stops. Why not apply the same logic to small moveable "airports".

The only use case I have thought of, and not saying this is the only use case. I think this would have a lot more appeal actually for back country and to carry larger loads than a C206 could carry into remote lodges. Otherwise, I am kinda curious on the proposed business model.

Tim

Of course it depends on the mission but the mission for this, doesn’t really exist. It’s not as simple as saying a small parking lot is authorized for a FW. No way anyone is going to allow this aircraft to operate in an urban area out of a parking lot. That’s an accident waiting to happen.

When transporting people / supplies, you generally either have a 0 ft requirement or a 3,000 ft requirement. There are plenty of existing helicopters that meet the 0 ft and airplanes that meet the 3,000 ft. This aircraft represents a very small niche. Kinda like the Alice aircraft.

Also, no way it’s going to come under operating costs of say a C206 in rural ops.

 

[MountainDude]

Of course it depends on the mission but the mission for this, doesn’t really exist. It’s not as simple as saying a small parking lot is authorized for a FW. No way anyone is going to allow this aircraft to operate in an urban area out of a parking lot. That’s an accident waiting to happen.

When transporting people / supplies, you generally either have a 0 ft requirement or a 3,000 ft requirement. There are plenty of existing helicopters that meet the 0 ft and airplanes that meet the 3,000 ft. This aircraft represents a very small niche. Kinda like the Alice aircraft.

Also, no way it’s going to come under operating costs of say a C206 in rural ops.

Here is what they say about the mission at the end of the video:

 

[Salty]

I’m not seeing any problem this is solving, that can’t be solved with existing designs for less money.

 

[Bell206]

Are you saying that they could put an uncertified engine (the APU) into a certified plane because it does not directly provide the power to the electric motors?

No. But an APU is not an "engine" in a type certification sense. In the Electra the electric motors are the aircraft "propulsion" units. The APU and the batteries provide the "fuel" for those motors. Since Electra is pursuing Part 23 certification they will be using that guidance to certify the APU, battery bank, and propellors installed on the Electra.

Now whether the FAA and other CAAs in the world will eventual?y require a Part 33 TC for those electric motors and a Part 35 TC for the props remains to be seen. But from what I've seen I doubt they will and certify everything under Part 23.

Also, my understanding is that a turbine engine costs several $100Ks. Why is the uncertified APU so cheap ($20K)?

First there is zero comparison between a TC'd turbine engine and a turbine that powers an APU assembly.

The $20k figure is for used, older T62s but still functional. I havent priced new/OH'd T62s but they would probably be $100k+. For comparison, a new/OH'd small TC'd turbine engine for a helicopter is more like $500k to $1M+

I don’t think they understand that the requirement for a 0 ft take off / landing is a real thing.

Its merely wishful thinking to replace helicopters as the main comparisons being used is trip distance. These eSTOLs fit more into the RAM side of the concept than the UAM side where the vertical component is. At least from the eSTOLs Ive dealt with. Where the eSTOLs have a niche is they dont need a conventional runway to move their cargo.

 

[Velocity173]

Here is what they say about the mission at the end of the video:

No way they’re lifting 2,500 lbs cargo in 300 ft. That test vid is just like airshow demos. Aircraft stripped down to try and demonstrate a capability that doesn’t exist in real world. Not to mention, that real world requirement is at a much higher DA than demonstrated in their PR vid.

 

[TCABM]

Not to rain on their parade, because what they’ve done is good work, but capability only gets you part of the way there.

Infrastructure to optimize the new capability has to be developed. Port San Antonio/Kelly Field is working to repurpose a portion of SKF to do that, but it’s not net new and it really doesn’t solve for the last mile.

The regulatory environment has to catch up for both certification and operations. Again, some of that work is underway, but it’ll take a while to really optimize for the use cases.

Where I see opportunity is for existing railheads/seaports, etc., that require intermodal distribution for the last mile. If I’ve got a big enough factory and I can integrate a place for these things to operate out of that solves for the last mile, then the juice could be worth the squeeze. But that needs a SIAP to be useful and enough throughput to make it economical.

Before the noise complaints and environmentalists get involved.