Scale model of 'Flying-V' airplane makes successful maiden flight | Hacker News Reader

Scale model of 'Flying-V' airplane makes successful maiden flight

edition.cnn.com

61 pointstomohawk84 comments

I do not want to be in one of these planes in the back row 30ft + from the center of gravity when this thing hits turbulence or is rolling while landing in bad weather. This was discussed in anther post some time ago about the same design type but can't find it right now.

I wonder if there's a way to counteract this with automatic flight controls that work both tactically and strategically.

tactical would keep the plane level, and strategic would set up for turns to take them more slowly than current jets.

I think about this because of the Tex Johnston 1-g barrel rolls during the demonstration flight where the people inside the plane experience "normal" g force.

Generally, I would think the layout would put fuel towards the tips and people towards the cg.

As an armchair engineer, I wonder about engine behavior at high angle of attack. It looks like it could be difficult to feed the engines enough air to maintain thrust.

I hope they work out all the details, because improved efficiency is a big deal. Although I also prefer the older Boeing blended wing body since it seemed to offer great efficiencies and immense interior space.

As I recall, one of the factors in abandoning the idea for passenger planes was the assumed reluctance of people to sit in a flying room (where they can't see out and could be more disoriented or uncomfortable).

> As I recall, one of the factors in abandoning the idea for passenger planes

Another was the different forces on passengers depending on where you were seated. A regular airplane everyone is situated on the same plane (ha pun!) more or less. But on a V config anyone far from the center would experience greater forces when the aircraft moved.

That's what I was thinking. I've been on a lot of planes that banked -hard- on approach. I can't begin to imagine what that would feel like sitting in this configuration.

Presumably the roll rate on that type of plane would be lower than on a traditional tube-with-wings design. So while the bank angle might still be high, it won't happen quickly.

As long as the plane is banked at an appropriate angle (relative to the rudder angle), the passengers shouldn't feel anything other than perhaps a bit more positive G force.

What about turbulence? I've been in some doozies where it felt like the pilot was fighting it hard, constant up and down and left and right corrections. I wonder what effect that fast change in altitude has, if any? Just G Force?

Turbulence that would push an aircraft up or down will have the same effect on either design.

However, turbulence that would typically cause a plane to roll quickly (such as hitting some sort of vortex or wake from another plane) should have less effect on a plane with a more widely distributed mass. On the other hand, once you start the big V plane rotating, it will be harder to stop rotating (take longer, unless the rotation energy is so great that the comparatively short wings simply cannot compensate).

We are at the point of fly-by-wire where there is usually a computer between the human and the control surfaces. This enables truly unstable aircraft (like the awesome F117 stealth fighter) to fly when they are inherently unstable designs. But as evidenced by the 737 Max debacle and the long ago A320 (320?) issue, sometimes the computer makes an unfortunately poor decision and does a bad thing. Point is, we are already there, so we might as well allow the computer to make a V fly wonderfully and save a lot of fuel and cabin noise.

Pilots do not fight turbulence, hard or lightly. The plane goes where it is pushed, and you go with it.

A very long (thus widespread) updraft might cause the pilot to reduce power, but that is very rare.

I'm not refuting you, but now I'm genuinely curious. We all know or think of turbulence like hitting bumps in the road, shaking, etc.. I was on a shorthaul, some embraer or similar sized plane, and experienced this only once. We kept hitting those big 'bumps', then I'd feel the plane dive down or up quickly. The kind that gives you the feeling in your stomach, like going over a hill as a kid in a car.

In my head to this day I assumed the pilot was quickly trying to find an elevation to avoid the turbulence, but your comment implies that's incorrect. So those quick pitches are also a form of turbulence? It was stomach turning, and honestly made me a bit uneasy.

What you call turbulence is really just a mass of air moving at a different speed or in a different direction, and the plane moved out of one into the next.

So, e.g., the plane passes into a downdraft near a cloud, and then into an updraft under the cloud, then into another downdraft, and then out. You feel four lurches. The pilot might be looking for a path that stays away from those, but you won't feel anything the pilot does.

That shouldn't be an issue for cargo planes though.

Ever hear of cargo shift? These would subject cargo to far higher g forces, making it much more likely cargo could move and unbalance the plane.

Google 747 crash Iraq for the most spectacular example of this happening in real life.

Yikes, but "unbalancing" was only part of the problem:

Guessing you're referencing National Airlines Flight 102

> ...improperly secured cargo broke free during the take-off and rolled to the back of the cargo hold, crashing through the rear pressure bulkhead and disabling the rear flight control systems. This rendered the aircraft uncontrollable, making recovery from a stall brought on by a change of balance from the shifted cargo impossible.

Also

> the cargo of five mine resistant ambush protected vehicles (three Cougars and two Oshkosh M-ATV's), totaling 80 tons of weight, had not been properly secured.

That's serious cargo.

I did not know it broke through the pressure bulkhead, like I said it’s an extreme example.

In the case of this plane design I think you’d see a lot of much smaller cargo shifting incidents, where banking one direction or another caused packages or their contents to shift to one direction. This could cause a more subtle change in center of gravity, that the pilot may counteract at first, but leads to further shifting or an unrelated problem that causes an accident.

I would have hated being in that bus driving towards the crash site. https://www.youtube.com/watch?v=7sUWC2jfjqI

Iraq? I know about the one that crashed taking off from Bagram, the only 747 loss related to Iraq I can think of was the BA one blown up in the Gulf War

I wonder why the flight plan couldn’t take this into account? Start turning sooner, etc.

Or make an announcement before starting manuevers. Have a place people could move into. Just spitballing.

The thing is, you don't design for the flight plan - you design for the "oh my god there's super strong crosswind, complex approach, and we have no fuel left for another airfield" and similar cases.

Flying wing designs have always facinated me and blows my mind how this was invented in the 1930s. Its fairly well known that flying wing in theory is more suitable for long term travel. But the biggest issue was ergonomics (as my professor put it, no one wants to feel like sitting in a movie theater for over 2 hours) and flight controls. Seems like they're trying to fix the ergo issue with the double fuselage-like design. It would be pretty exciting to sit in one of these if the idea picks up.

Interesting / weird concept. I'm cynical that it'll take off (ha) as a concept for passengers, given that they'll either be sitting at an angle (in relation to the flying direction), or they'll have to tilt all the seats making the internal seating arrangement weird and ineffective. But counter-intuitively, it looks like a simpler design for planes compared to those with wings.

There are business class layouts at angles and no one seems to mind.

https://en.wikipedia.org/wiki/Herringbone_seating

BA's business class has seats facing backwards too. Never bothered me, and I'm obviously not alone in that.

The things that help most for dealing with motion sickness on planes are having a good perspective view of land and being the one flying the plane. Those don't work so well for commercial air travel, so G forces are kept pretty modest and directed down and there aren't sudden movements. Sensitive people do better around the center, but otherwise, people mostly do OK on planes, even at a slight angle or backwards. This isn't "Harry Potter and the Forbidden Journey."

I'm not sure that the angle is severe enough to matter? I can see people becoming accustomed to it.

Would the seating arrangement be less effective if you angle the seats directly forward but arrange them in a staircase pattern down the wing?

It would be really difficult to move a trolley down a staircase arrangement.

You could add a rail on the edges, and have the trolley ride it.

This concept is not new. Lifting bodies have been around since the 20s.

Boeing and NASA have both experimented with this https://en.wikipedia.org/wiki/Blended_wing_body

Nowhere is it claimed to be a new invention. On that page itself there's only two or three that were aimed at passengers, none of which ended up commercially viable.

But it also has (or links to) reasons why it's not been developed further for passengers; to quote:

"Passengers are unwilling to sit in windowless environments." - not an issue with this particular design

"Passengers furthest from centerline will be subject to potential discomfort during wing roll. Extreme discomfort results in motion sickness." - Definitely an issue I think.

(on the X-48): "[...] passengers did not like the theater-like configuration of the mock-up; the design was dropped for passenger airliners" - Also not really an issue due to the dual-fuselage design of this one.

NM: I didn’t see the double tube design.

The blended wing body looks very different from a V shaped body.

The concept is the same. What makes you think the practicalities are different though?

I'd classify this as closer to a flying wing than a blended wing.

It looks cool and sounds cool but I doubt it will get popular.

You have entire companies, organizations, groups, standards, certifications, training and employees built around the current airframes. Its not going to be easy to change all of those overnight.

Not to mention, current airframes are the way they are because its what works best. Ever wondered why engines are always on the bottom of the wings, never on the top, or almost never on the back? Because its close to the ground and easy to maintain. Ever wonder why the wings are pointed upwards and swept back? Because those are the most fuel efficient and stable configurations. Flat fuselages like in the V plane means less heigh clearance which means passenger planes will have less space and freight planes will have trouble carrying certain shapes of cargo. All in all, that makes it hard to sell for any airplane manufacturers that want to make it

The current airframes are the way they are because of decades of incremental improvements and selections of which designs work and which don't. The entire industry or even a good enough chunk of it wont just drop that overnight

So you think that no matter how much better technology gets, we're stuck with tube-with-wings _forever_ because that design was the first to be made practical? Nobody's saying we have to make an "overnight" switch, but you seem to be suggesting that nothing will ever change, and I think that's silly. It probably won't be this design, because change is definitely hard, but ultimately if some novel design can make the economics of commercial aviation (or some subset thereof) work then all the inertia of the current paradigms won't be able to stop progress over time.

I think you missed the parent's points in several places.

> So you think that no matter how much better technology gets, we're stuck with tube-with-wings _forever_ because that design was the first to be made practical?

Parent listed specific technological advantages of current designs over the flying wing configuration in question (maintenance, efficiency, etc.). The use of the word "overnight" twice suggests he wasn't making a "forever" claim.

And there is a real point regarding current infrastructure. For example, the entire 737 Max debacle exists because airlines want to avoid the expense of retraining pilots, and Boeing rushed to make that happen in the face of competition from Airbus.

Actually, I don't think I missed anything.

I'm aware that their argument is very rooted in the status quo, and I agree that current infrastructure is a big roadblock to adoption of new technologies (in fact, you may have missed that part of my comment), but if they wanted to allow for eventual adoption of new technologies then they should have said so. Instead, their comment dismissed this new technology as impractical today without addressing the future at all, which I think is an incomplete analysis and potentially harmful if it were to be applied by the people actually making decisions about which developing technologies to invest in. That's why I replied.

There is also the issue of structural complexity. Today, extending the body by another 10 feet for a couple of extra rows of seats is mostly repeating a section that already exists. Yes, there are a lot of calculations around rebalancing and flight characteristics but the construction of the extended body is pretty straight forward. How do you create smaller and larger variants of this v-wing design? Not as modular.

I don't know, the entire rocket industry is having to to re-orient itself around SpaceX's reusable rockets.

And given current usage, the gains in better rockets presumably pale in comparison to the potential savings / improvements that could be provided by new airframe designs.

One could make the argument that prior to SpaceX’s entry into the market, there was stagnation due to limited market participants, cost-plus contracts, etc.

Commercial aviation is the exact opposite of this: Since deregulation, airlines have been operating in a highly competitive market with external pressures that have forced adoption of new technologies (oil prices => fuel efficiency, noise regulation => high bypass engines, labor costs => replacement of the flight engineer)

You're confusing airlines with manufacturers though. We're talking about an airplane design here, not the operation of it.

Effectively there are only two international long-haul airplane manufacturers (i.e. producers of planes that would compete with the OP) – Airbus and Boeing. That seems like "limited market participants" to me.

What will be really interesting is if suborbital reusable rockets reach a similar cost per mile as long distance planes.

I would get some passenger evacuation tests done before I went any further with making this a passenger design.

The FAA and JAA require series of evacuation tests as part of certification. During the JAA tests for the 737-NG, Boeing was unable to achieve the same evacuation rate as with the FAA tests. As a result, JAA capacity was lower than FAA capacity for these aircraft.

Am I the only one disappointed that they didn't make a plane in the shape of a Gibson guitar?

That sounds like a youtube opportunity, go nuts!

It looks like the Aereon. https://en.m.wikipedia.org/wiki/AEREON_26 Which test flew in 1971. There is a book about its development “flying deltoid pumpkin seed”

Some more info: https://www.google.com/amp/s/amp.theatlantic.com/amp/article...

non-amp: https://www.theatlantic.com/technology/archive/2011/03/the-r...

non-mobile wiki: https://en.wikipedia.org/wiki/AEREON_26

What's interesting is the split tube design. Very different from usual flying wing designs I've seen. possibilities for more windows?

Who needs windows? Just give them all some AR/VR-Goggles, and have them look through the plane in any direction, like the helmet in the F-35 allows.

I think any perceptible latency and turbulence together would probably turn the plane into a vomitorium. Unless perhaps all the passengers where fighter jet pilots with iron stomachs..

Regulations

Thanks wikipedia page doesn't seem to have any photos, but looking around on the net someone's made a (small) flying drone based on it:

https://www.youtube.com/watch?v=bdH2WaIfOPE

Seems to work ok. :)

Photos would help. Anyone have a link to any?

Yes, and a video:

https://www.flightglobal.com/aerospace/flying-v-model-embark...

It's a scale model that flew, not an actual aircraft. It's an interesting idea though.

Neither article addresses the flaw that always comes up when this design is proposed: By placing the passengers in the wings instead of the the middle, the would be exposed to much stronger turbulence (probably at a level unbearable for the general public).

Forget turbulence. Normal flight characteristics would be unbearable. Some of the approaches to Chicago Midway airport have ~45 degree bank angles.

The bank angle wouldn't be the problem. It would be more the change in roll rate. People don't have problems when the elevator is in constant motion. It's the start and stop that cause the feelings.

It probably wouldn't be all that hard to build some sort of rate of rate of roll limit into the flight control. Or just have the pilot smoothly move the stick to the desired rate of roll rather than snapping it to the desired position. They are severely limited in what they can do with pitch when there are passengers. This would be a relatively minor limit to what they can do with roll.

Why would this be unbearable further outside on the wing? Wouldn't the angle still be the same for everyone on the plane?

The angle isn't the problem, it's the 40' vertical drop for the passenger near the wing tips.

What could be a solution would be the ability to angle the winglets up or down and use those for your banking instead of the body.

The turning will cause banking, or just lead you to a stall unless you have ridiculously słów turn rate (bad idea)

That model is significantly smaller than the CNN article led me to believe.

Here's a youtube video of the model from the KLM official channel: https://www.youtube.com/watch?v=MFoc8wbuasM

These sorts of typos really annoy me

> Dutch airline KLM has agreed to find development of V-shaped aircraft

Do publishers not have any proof readers any more?

To be fair, there are multiple entities taking revenue away from them over the years. Something has to give.

So why this over a delta (flying wing) shape?

Frankly, a flying wing would at least have placement of seats in a non-roller coaster configuration.

Compatibility with existing airport facilities.

How is this different from the US military B2 style aircraft?

They look superficially very similar.

The photo in the article is deceptive; better pictures are here: https://www.flightglobal.com/aerospace/flying-v-model-embark...

One's military and carries bombs, the other is commercial and carries passengers.

Can the title be adjusted to make it clear it's a scale model?

Thank CNN for that. Clearly clickbait. The Flight Global article someone else linked to has the word "model" in its title and a lot more useful information.

If there's going to be a change, I suggest just switching to the other link.

There seems to be a lot about liquid-hydrogen as a fuel for passenger jets lately.

IMHO, it's totally unsuitable.

Is there another reason it's being pushed, eg it's an output of some other process that is desired?

This seems like a useless efficiency, given no passengers would willingly fly in it, and it’s not good layout for cargo either.

" given no passengers would willingly fly in it,"

Why do you say that?

Most of the available seating would be far enough off the center axis that every time the plane banked you’d experience a rapid drop or acceleration as your wing fell or flipped up.

And then there is the paucity of usable window space.

Because the "cheap seats" further away from the centerline would be like a six hour roller coaster ride at Six Flags.

The centerline seats would have no windows (doesn't matter to me, but does for some people).

Motion sickness is much more likely when people can't see the horizon. This might be mitigated with forward facing monitors for each passenger.

But I'd pay for a six hour Six Flags experience. Turbulence and G's are fun for some.

Barf Express.

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