Does eSTOL Hybrid Power and Blown Lift Beat Vertical Powered Lift? – FutureFlight

Electra is pioneering the development of a hybrid-electric short-takeoff-and-landing aircraft that it says will deliver far lower operating economics than new electrical vertical aircraft. It expects the nine-seater to operate from downtown spaces as short as just over 300 feet, opening up new urban and regional air services that aren’t viable today.

#aviation, #flying, #airplane

[JoeyBlogs]

This concept has the greatest chance of near term success, when compared to standard EVTOL.

[SoloRenegade]

this guy has the right mindset. this can work with or without new infrastructure and is not a radical design change making it less risky

[EdisonAero]

Great to see them succeed! Our approach is very similar ~ going for estol rather than vtol for all the reasons covered in the video.

[peteregan]

Surprised other aircraft makers are not taking this approach.

[seaplaneguy]

This video is excellent in that it points out the flaws of VTOL.

Blown wing with boundary layer control can yield CL = 10 vs flaps only at 2-2.5 CL. This tech shown is likely only 4.5 CL similar to the X-57 shown in video. They fail to make it right, and lose out on lots of advantages.

A hybrid (electric or hydraulic) would appear to be the next step, but it is not. There is a lot more to success than just better CL. The genset/pump with mirrored motors (EV or hydraulic) consume 14% to 19% of energy at 90% to 93% efficiency. (0.93x0.93 = 0.86 and 0.9 x 0.9 = 0.81) The added weight is also a big no-no.

This all fails to understand the future of aviation.

1) blown wing
2) Active Drag Reduction
3) 60% efficiency full power, 75% in cruise.
4) short term boost power
5) ultra quiet props
6) CO2 and water capture
7) Fuel making from solar or nuclear
8) roadable
9) landing on EXISTING roads not used during different times of day.
10) Door to door taxi
11) Optional VTOL or 25 mph at 2x costs with full transition when needed only. 25 MPH is better than VTOL, unless VTOL is key. 99% of landings are at 25 MPH (residential speed limit).

[stonebear]

The other thing to add to that is true all-weather capability... put an IR camera in the nose of that thing and hook it to the inevitable glass panels in the cockpit...

[mikemaloney]

Why not imbed the motors in the wings for less more even prop blast distribution?

[removechan]

Electra's plane is amazing, it's a perfect blend.

[snowowl]

Great idea! Never get into anything that doesn't glide, like drone planes.

[glike]

Decades of Aeronautical Engineering experience tells me this design is a winner. Make a float plane, amphibious, and Ekranoplane versions to cover all markets.

[heathcwalker]

I love it. What will be the speed and range? Why aren't more planes adopting the toroidal propellers?

[kfy-]

coefficient of lift is a function of geometry not flow condition. "blown lift" works by increasing the dynamic pressure which increases lift, which is a concept over 100 years old.

[rossnolan]

Blown lift is old hat - Breguet built such an aircraft also intended to use STOLports in the 60s Eastern trialled it even. Having UNblown tail surfaces exposes the aircraft to potentially uncontrollable 'excursions' due to gusts at low speed when "hanging on the props' at critical height and speeds . The blowing effect leads to enormous induced drag and may make a go around impossible --getting too slow can be fatal (backside of the power curve) that said, better than VTOL in this respect . It IS powered lift unless you intend to always fly ABOVE the power off stall speed (ie not power/lift dependant ) -the 'airbrake effect' of stopped props will also equally destroy lift on the wing behind -sideslipping might be prohibited due to separation from the pods .
Landing technique with highly deflected flaps is different --just as gliders with 90 degree flaps must be respected should an undershoot be in prospect . The DH Caribou is a good example of massive blown flaps - it lands nose DOWN and can be 'taxied' on the nose wheel in light winds --DH investigated this whole area decades ago including having a REVERSE thrust tail prop to allow spooling up the 'lift' props without speeding up --this aircraft should have that .

[markthomasson]

STOL makes so much sense. Is VTOL more of a sexy fad?
Hybrid with a generator, shame, but with the advances in battery tech, easy to replace the genny with more batteries. At least for shorter routes.

[dunkTheFunk]

have the rotors pivot to allow for full VTOL in emergencies or shorter runways. Best of both worlds.

[rossnolan]

I recall John Langford from the MIT HPV projects so he should be aware of the potential to reduce power requirements drastically over both eVTOL and CTOL state of the art -- there is a trade off for blown lift since it needs high slipstream velocity over the wing hence small fast turning props -potentially noisey and giving lower acceleration than if larger (note the gaps between the props here) -- I assume they have done their parametric studies around this . Span is limited for practical reasons and so induced drag and power are higher than need be (high Cl at high air velocity makes for higher power than if compared to unblown high span and high area at flight velocity --loss of both thrust and lift together and need to retain symmettry by shutting down 'opposite' props makes for a critical failure case --the messing up of lift if all power is lost in glide mode could be drastic. The similar Maxwekll x57, now defunct --used the same design philosophy -- it was abandoned before being flown . Stolports are exceedingly rare and stol flight is notoriously dangerous being power dependent and 'behind the power curve ' - a big trap for the unwary. (Cessna deleted it's 40 degree flap setting because of this - I have personal experience of the 'backside

[adamburck]

Is there any reason a vectored lift aircraft (Joby, Archer, etc.) cannot take advantage of a short runway when available and achieve the same savings under the favorable circumstances?

[sseim]

Yes, it does. This is the future of short haul. A few know that MIT is heavily into this project. This form factor is actually the future of general aviation as well. No kidding...

[skyloveglobalnelsonbarbonc]

Together we fly evtol 100% 🎇🎆🎆🎆♥️♥️♥️♥️♥️♥️♥️

[rossnolan]

That extra big tail outside the propwash is more exposed to crosswinds and gusts that will need differential thrust to counter, STOL aircraft have this problem and need special measures to counter it for example the complex control mixing of the DH Caribou and the Canadair CL84 . Stolports are a bit of a problem due to the space needed in built up areas, approach angles clear etc unlike backwoods stol but both are fraught with flight behind the power curve and gust effects, the X57 multi prop blown wing et al failed to live up to expectations.
A wing seeing vast swirl and festooned with nacelles cannot be that efficient just basic physics