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Cora – Kitty Hawk's prototype air taxi [video]

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Re: Cora – Kitty Hawk's prototype air taxi [video]

#271

Post by dingaling »

lallysingh wrote: post #102
ransom1538 wrote: post #70

Small planes have had parachutes for quite some time [1] now and have saved many lives. Why on earth would this company put people up into the air unmanned without one? [Personally, if a parachute was onboard I wouldn't mind jumping into one.] https://www.youtube.com/watch?v=kQyrPVIIQdE

AFAIK it's basically just Cirrus that has a parachute system (CAPS in their case). Others don't, and there are plenty of other plane manufacturers with many, many planes in the air.

Cirrus were a pioneer in factory-fitting but other types, even microlights, are also fitted with recovery systems. Magnum is a common brand in Europe.

BRS who make the CAPS for Cirrus also provide retrofit kits for Cessna 172 and 182.

Re: Cora – Kitty Hawk's prototype air taxi [video]

#272

Post by JohnJamesRambo »

Jyaif wrote: post #55
JohnJamesRambo wrote: post #42

Earlier quoted context omitted.

Care to share this infinite energy idea?

You know very well which source he's talking about. And he said say near infinite, precisely to defend against obnoxious commenters.

I still don't know, I'm sorry.

Re: Cora – Kitty Hawk's prototype air taxi [video]

#273

Post by JohnJamesRambo »

stephengillie wrote: post #78
elago wrote: post #65

Earlier quoted context omitted.

Could you please name the technology? I work with renewable energy and I have no idea. Are you talking about nuclear?

Ancestor comment is probably daydreaming about being in a Kardashev 2 civilization with a full Dyson Swarm collecting 100% of the Sun's total energy output, in all directions. Some estimate we're currently only at Kardashev 0.8, harnessing about 80% of what energy from the Sun hits the Earth, while others argue that this percentage is much lower. Ideas are easy, implementation is hard. Edit for clarity.

We aren't in the same universe as 80% of the Sun's energy that hits Earth being used.

The numbers I'm seeing are 174 petawatts hits Earth and the world uses 18 terawatts of energy.

Re: Cora – Kitty Hawk's prototype air taxi [video]

#274

Post by cbr »

knodi123 wrote: post #238
cbr wrote: post #216

Earlier quoted context omitted.

15 minutes? If you flew in a small aircraft regularly, you would know it takes 40-60 minutes to prep a plane from park to airborne in zero traffic How much of that prep is eliminated by going full automation? Isn't most of the prep the pilot running through a checklist? If there is unavoidable time consuming checking, you could do that in advance and provide the plane as an autonomous taxi. So it shows up, picks you…

> Isn't most of the prep the pilot running through a checklist Yes, but... Things like "check your propeller for cracks", or "verify that the control surfaces are actually moving when the controls say they should have moved" should not be skipped. But you can skip a lot of things just by virtue of this being an electric vehicle - like "visually verify fuel level without using the gauge", or "check oil level", or "tes…

If these are automated, though, they can be done in parallel. A camera pointed at the propellers can be checking them for cracks at the same time that another camera is checking that control surfaces actually move.

Re: Cora – Kitty Hawk's prototype air taxi [video]

#275

Post by vadimberman »

mrep wrote: post #143
clon wrote: post #24

Earlier quoted context omitted.

I agree. People talking about flying cars sound a lot like people demanding faster horses. Or flying horses. I do not think the American dream of a private car scales too well to the future, be it with rubber wheels or tiny propellers. Especially given the population growth. Instead, a brief visit to Singapore, for example, will convince anyone what the future of transportation looks like. A public transport system,…

How safe is Singapore public transportation and walking? The reason I ask is that neither are as safe as driving here in the US which i consider a major blocker in the public transportation utopia people keep dreaming up. Relevant discussion I have had about this topic: https://news.ycombinator.com/item?id=16462803

> How safe is Singapore public transportation and walking?

Extremely safe. Even the whiniest people in Singapore (and that's a high bar to clear) will never say that Singapore is unsafe.

Once in a while I see videos of cars not stopping in front of a pedestrian crossing. These posts result in a universal condemnation.

Also note that the UK-style pedestrian crossings include a buffer space next to the actual crossing.

In terms of public transportation, you have the subway (MRT), the light rail (LRT), and the buses. All new, and most of the MRT plus LRT are automated.

Additional aspect is drink-driving. The alcohol is also heavily taxed (almost Demolition Man style: "x is not good for you. What's not good for you is illegal") and the way the government views drugs is clarified in the disembarkation cards saying "Death to drug traffickers" (and they actually mean it), and with the combination of high availability of public transport complemented with cheap taxis / ride-sharing and low availability of intoxicating the DUI is pretty much non-existent.

In the US, the sidewalks are scarce in many places. But that's pretty unique, you don't need to go to Singapore to see streets with normal sidewalks.

Re: Cora – Kitty Hawk's prototype air taxi [video]

#276

Post by knodi123 »

cbr wrote: post #274
knodi123 wrote: post #238

Earlier quoted context omitted.

> Isn't most of the prep the pilot running through a checklist Yes, but... Things like "check your propeller for cracks", or "verify that the control surfaces are actually moving when the controls say they should have moved" should not be skipped. But you can skip a lot of things just by virtue of this being an electric vehicle - like "visually verify fuel level without using the gauge", or "check oil level", or "tes…

If these are automated, though, they can be done in parallel. A camera pointed at the propellers can be checking them for cracks at the same time that another camera is checking that control surfaces actually move.

there are better ways to detect aileron deflection via automation than with a camera, but I take your point.

Re: Cora – Kitty Hawk's prototype air taxi [video]

#277

Post by baybal2 »

danielvf wrote: post #47

Contrary to almost every comment here so far, this is both innovative and energy efficient. Let's talk energy efficiency first. Once it's up in the air, it's has a similar profile to a normal single engine airplane. A Cirrus SR22 can go 1,200 miles on 80 gallons of gas. That's roughly speaking 15 miles per gallon - better than many pickup trucks or large SUVs. And that's while going 180 mph. Slower is more fuel effic…

It would be happy if they had anybody of who has some semblance of an aircraft design engineer background.

Their first try: zee aero made a barely flyable contraption that was nuked by American FAA, and rightfully so.

http://wap.business-standard.com/article-amp/international/l...

This time, I don't see this being much better. My early childhood aspiration was aeronautics. I believe as somebody who built a semiflyable motoglider as a 15 years old in 2006, I can comment on technical soundness of this. Biggest red flag in the design are fans in front of the wing. Turbulence from them will be randomly stalling the wing, and most likely asymmetrically - which leads to a corkscrewing risk, especially with that huge elevator.

Re: Cora – Kitty Hawk's prototype air taxi [video]

#278

Post by baybal2 »

godelski wrote: post #247
syntaxing wrote: post #155

Earlier quoted context omitted.

I agree that the technology is exciting to see but I think there is a lot of negative comments because there is a lot skepticism (which engineers tend to be including myself due to the nature of our work). That being said, most commercial flights are actually on autopilot during cruise. Pilots can choose to use auto takeoff and landing as well but I believe it requires a specific license and copious amount of paperwo…

As a pilot and engineer, I think there are good reasons to be skeptical. Here's some of my questions. 1) Can it autorotate? Or in an emergency does it have to glide? 1.5) What's its glide distance? Cruising altitude? There's a lot of drag from those propellers so I imagine its best glide speed isn't great. 2) How are you going to get it in a city? Seems like you're going to have to go to the local GA airport (which a…

FAA struck down google's first prototype, that's why they test in NZ

Re: Cora – Kitty Hawk's prototype air taxi [video]

#279

Post by gambiting »

thaumaturgy wrote: post #257
gambiting wrote: post #194

Earlier quoted context omitted.

These "driving related" injuries and deaths stats are almost always skewed because they include fatalities/injuries for drunk driving and night time driving. Someone only driving to work and back is at an absolutely minuscule risk of injury/death from driving.

I'm happy to accept ~pc86's correction up above, but I disagree with this rebuttal. The risk is minuscule in the absolute sense (several hundred fatalities per billion miles), and if you are driving drunk (or tired, or on painkillers, or while texting), your odds of collision certainly go up. But just because you aren't doing those things, doesn't make you any less at risk from other people doing those things. You ar…

Absolutely, I'm just saying that the risk you are in changes depending where you are and what you do, there is an average amount of risk but it doesn't apply to everyone.

I understand that some people have very dangerous commutes, but for some it's literally 10 miles of traffic moving at Yes, there is still a chance someone else around you could be drunk or speeding or distracted, but if you are sitting in an 8-lane jam that's not really going to do much damage.

Re: Cora – Kitty Hawk's prototype air taxi [video]

#280

Post by pc86 »

godelski wrote: post #239
DennisP wrote: post #221

Earlier quoted context omitted.

He specified "general aviation aircraft not designed in the 1950's." The Cessna 172 was first flown in 1955: https://en.wikipedia.org/wiki/Cessna_172 Also, it may be worth taking into account that airplanes travel in straighter lines.

Planes are updated, just an FYI. And most GA aircraft are older. That's how most people fly, by buying an aircraft that is the price of a car ( I fly a Cherokee 140. One of the most common aircraft, as with the Skyhawk. My fuel consumption is 8.4gal/hr at 75% mixture and 5.6gal/hr at 50%. Assuming I'm doing an average ground track of 100mph (for easy math), that's 12-18mpg (not counting that I'm 100% rich at TO and L…

Cherokee 180/181 checking in! $4.09 would be great, $5.12 at my base this morning. $0.35 club discount helps though.
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