Ten-engine electric plane prototype takes off [NASA]

Phys.Org ^ | 05/04/2015 | by Kathy Barnstorff & Provided by NASA

[NorthMountain]

To me, it looks like a submarine with wings.

[NorthMountain]

Ya think?

[SES1066]

If it flies, why is it being lifted by a crane?

Picture was from the testing regime before free-flight. I chose it as it showed the aft props better than the ones in the first picture.

[hoosierham]

A battery that can store enough energy for a useful flight range and payload would be astounding.

Currently ,far more energy is released in usable form by combustion of a pound of liquid hydrocarbons in an engine versus the usable energy delivered by a pound of storage battery.

[NorthMountain]

According to the article, their goal is a diesel-electric hybrid system.

[ZOOKER]

The tail rotors make me think the aircraft is tail heavy which means it will be unstable in horizontal flight.

Wing is swept, so when you stand it up on edge for hovering the center of lift would move forward.

If they work the bugs out, I suppose you'll see these hovering over every demonstration taking pictures or dispensing tear gas...

[PapaBear3625]

The idea reminds me of "The Bus" from "Agents of S.H.I.E.L.D."

[no-s]

Now theyre playing with propeller airplanes?

Doesn't one of those "A"s stand for Aeronautics or Aerospace or similar?

[zeugma]

Zack Johns is the GL-10's primary pilot. He says flying the ten-engine aircraft has its ups and downs, but it really flies more like a three-engine plane from a control perspective.

groan.

[Red Badger]

I wonder if they are wired in series or parallel, or series-parallel?.................

[Red Badger]

If it flies, why is it being lifted by a crane?

That's not a crane, it's the power cord, silly................

[justlurking]

Looks like its being supported by a sling.

In that picture, it is. But, if you follow the link to the article, you'll find an video showing:

1. vertical takeoff
2. transition to horizontal flight
3. transition back to vertical flight
4. vertical landing

Seems a huge waste of taxpayer money, IMHO.

This is the third prototype, larger than the first two. The important part is that it is scalable: just add more engines to generate more lift.

There are a lot of practical uses for this, especially because it can transition to horizontal flight and use much less power per mile. Of course, it will need a new control system.

The cool part is that it demonstrates the concept is much easier to accomplish, without all the complex mechanicals required for the V-22 Osprey.

[justlurking]

I think you guys missed the important part: I couldn't see any rotor pitch control in this prototype. That's a huge mechanical complexity in helicopters and the V-22.

It was completely controlled with differential thrust: left/right sides control roll, front/back control pitch.

[NorthMountain]

It was completely controlled with differential thrust:

That's also how quadcopters work.

[Yo-Yo]

It was completely controlled with differential thrust: left/right sides control roll, front/back control pitch.

Something trivially easy to do in small scale (see the myriad of RC controlled quad copters) but is almost impossible with a full scale aircraft because of the required thrust and throttle response. Full scale helicopters use pitch control because it reacts faster than throttle control.

The thing that killed the XC-147 was the wing flex being incompatible with the cross shaft that connects all four engines together. The cross shaft is vitally important for an engine out situation.

[hoosierham]

Can a diesel-electric hybrid total weight be less than IC or jets? I don’t see how.

Any day NASA will announce the discovery of balloons powered by the hot air from Al Gore ,obama, and all the other champions of failed or narrow niche technologies.Technologies that just happen to make them rich through government subsidies are the politicians and advocates favorites!

[NorthMountain]

Can a diesel-electric hybrid total weight be less than IC or jets? I don’t see how.

I don't know.

I do "know", from talking to friends who are GA pilots, that there's some work going on in developing piston aircraft that used diesel, rather than spark ignition engines. This is driven by a desire to run them on JET-A, rather than AVGAS.

The diesel-electric setup would allow separating the diesel engine from the propeller nacelles ... possibly a good thing on a tiltrotor aircraft.