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JetZero

jetzero.aero

251–260 of 277 posts

Re: JetZero

#251
post #247
post #160

Earlier quoted context omitted.

I hope I'm not overinterpreting, but I get the sense that you think that's morally better than simply avoiding contrails. If so then this is surely a mistake! While an individual who imposes heavy costs on himself to do something socially valuable is certainly demonstrating commitment to the cause, the best solution for society is the one with the lowest costs.

Actually, lots of people acting together regularly accomplish things - almost everything wortwhile is accomplished that way, probably back to our non-homo ancestors. As a simple matter, it keeps my city clean - we all put garbage in the bins (yes there's a law, but no way could it be enforced if the great majority of people didn't do it already). More dramatically and recently, the protests in India. > society Societ…

I think you've misunderstood my comment. I understand that people can do things together. My point was that the best thing to do together is to solve our problems at lowest total cost, and that choosing a high-cost solution can be individual "virtue signalling".

Re: JetZero

#252
post #250

Earlier quoted context omitted.

Consider dropping spaces too. It'll make your comments even more Unique and Quirky! And it won't impact readability in a way you care about!

you ok man

Probably not. Is anyone?

Look at this world we live in. Billionaires are living it up and climate change is wrecking winter and here we are in the mud, someone like you can't even afford a simple shift key.

It's all so crushing.

Re: JetZero

#253
post #250

Earlier quoted context omitted.

you ok man

Probably not. Is anyone? Look at this world we live in. Billionaires are living it up and climate change is wrecking winter and here we are in the mud, someone like you can't even afford a simple shift key. It's all so crushing.

wtf im being poor shamed for lack of caps by the rss feed bourgeois

Re: JetZero

#254
post #164

Earlier quoted context omitted.

> Specify a maximum roll rate in training and normal-law software and this problem is solved I’m wondering whether there are major airfields with traffic patterns that require roll rates that would exceed whatever maximum is desired for comfort. My intuition is that the situation would be tolerable at most airfields but that normal-law limits that are too restrictive could be dangerous.

> major airfields with traffic patterns that require roll rates One, this is where the more lifting body turning faster with less roll kicks in. Two, I suspect those airfields would also be the last ones to add terminals that can dock with a non-standard plane.

> this is where the more lifting body turning faster with less roll kicks in

Can you explain what you mean? If an aircraft follows a given trajectory (center of mass position as a function of time x(t) where x is a 3D position), then it has an acceleration a(t) that is just the second derivative of x(t) and has nothing to do with the shape of the airframe.

Now account for gravity and kinematics: the force per unit mass that must be applied to the airframe is F/m = a + g • ẑ (ẑ is the upward unit vector).

The exact same result applies to a person inside the aircraft. If you want comfortable flight you need F/m to have no sideways component from the perspective of the passenger (and in the absence of gimballed seats the passenger is facing the same way as the airframe).

So far none of this has anything to do with the shape of the lifting body. And I’m wondering why you think more lifting body makes much difference. There are only two real flight parameters knobs you can turn to achieve this condition. You can roll, and you can sideslip. And, unless my intuition about the geometry is quite wrong, you would need a very extreme sideslip angle (pointing the nose quite close to the center of curvature) to have much effect on the required roll angle. So the roll angle needed is mostly a function of the angle of the acceleration vector plus gravity relative to the velocity and not much of a function of how the airframe is able to generate lift.

For another way to think of it, imagine a fancy rocket performing the exact same maneuver with no lift or drag whatsoever. Either the rocket could point itself toward the center of curvature (adjusted for gravity as above) and use its main engines to generate the required acceleration (extreme sideslip), or it could point roughly the same direction as its velocity vector and use a sideways-firing rocket to generate the required acceleration. If the latter, then, for passenger comfort, the roll angle needs to be such that the sideways rocket is in the front/back/up/down plane with respect to the passengers, which determines the required roll angle.

And I don’t see how any of this has anything to do with the same of a lifting body or the actual capabilities of the maneuvering thrusters of a hypothetical rocket. On a given flight path, you have a constrained set of valid roll, pitch, and yaw angles.

Re: JetZero

#255

Earlier quoted context omitted.

I don't see how having a marginal amount of single-engine aviation flight experience is relevant to Dunning-Kruger. If anything, it's taught me how little I know about "real flying" compared to CFD and systems engineering. Commercial aviation is conservative because aviation is "hard" and mistakes in aviation are "extremely costly".

It's a lot like saying, "as someone 5 hours into driver's ed in my mom's honda civic, I believe that future stability control algorithms in self-driving cars..." Or the difference between a (noob) software user and a software engineer.

No. I'm, in essence, saying the opposite. To use your analogy "as someone with 5 hours into driver's ed in my mom's civic I now realize how hard driving actually is and why ALL cars still have 4 wheels, still use a steering wheel, and still have seat-belts".

Re: JetZero

#256
post #226

Earlier quoted context omitted.

Please lookup the flight envelope, cruise fuel utilization, and stall characteristics of the Dyke Delta along with its cargo capacity. Then you'll understand why so many Cessna 172s were built.

It wasn't more fuel efficient than the standard plane? Was it because of the propeller up front?

It was more fuel efficient only over a very narrow band of the entire flight envelope. Also, it suffered from snap-stalls and very poor stall recovery due to its delta wing.

This is, primarily, why you only see delta wings used in super-sonic aircraft where these limitations are more than made-up for its ability to go trans-sonic with (relative) thrust efficiency.

Re: JetZero

#257
post #246

Earlier quoted context omitted.

I just want to go to an hospital, get an injection, fall asleep and wake up on a bed at another hospital somewhere else.

This is actually the plot of the hit TV show Severance.

Which I enjoyed quite a lot, for unrelated reasons

Re: JetZero

#258

Earlier quoted context omitted.

The people they do that have a lot of experience and make a lot of money. Fortunately, most of the world doesn’t have the software business’ cavalier attitude about safety-related things being perfectly safe.

Boeing comes to mind as a counter example.

Just because they are worse than they should be doesn’t mean they’re comparable. Cheap Chinese consumer goods? Sure. But aerospace and software aren’t in the same galaxy when it comes to QA and accountability. Source — I worked in software for decades and currently work in aerospace manufacturing.

Re: JetZero

#259

Earlier quoted context omitted.

It's a lot like saying, "as someone 5 hours into driver's ed in my mom's honda civic, I believe that future stability control algorithms in self-driving cars..." Or the difference between a (noob) software user and a software engineer.

No. I'm, in essence, saying the opposite. To use your analogy "as someone with 5 hours into driver's ed in my mom's civic I now realize how hard driving actually is and why ALL cars still have 4 wheels, still use a steering wheel, and still have seat-belts".

People with a handful of hours towards a private pilot's license have no (zero, zip, nada) expertise or insight when it comes to the design and manufacture of commercial airliners. You might feel like you do, but it has no basis in fact, because the constraints that really matter are things that engineers have spent a hundred years working out by trial and error (and crashing a lot of aircraft).

We wouldn't take airliner design advice today from the Wright brothers, either.

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