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A successful Japanese trial of a ramjet engine designed for Mach‑5 aircraft

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Re: A successful Japanese trial of a ramjet engine designed for Mach‑5 aircraft

#101

Post by bruce511 »

mikeshi42 wrote: post #99
bruce511 wrote: post #95

Earlier quoted context omitted.

Yes, ymmv (a lot). But alas buffer time is getting higher, not lower. Yes, TSA is a big part of the problem. It's less "how long it took" and more "how long can it take". I've personally experienced those days where "TSA decided to go slow" and a couple hours disappears. The 5 minute days just make that worse. Yes, the airport matters. If you're at some small regional it's no big deal. JFK or Atlanta etc is another t…

I have _yet_ to hit a time where TSA can make multiple hours disappear. Precheck w/ touchless ID lines are virtually empty at most airports, the actual security screen itself is quite fast given almost nothing needs to be removed from your bag these days. I still tend to arrive early, but I don't mind getting work done at the airport, especially at a lounge - though I've arrived very close to departure other times an…

>> I have _yet_ to hit a time where TSA can make multiple hours disappear.

Lucky you :). And I hope you stay lucky! Alas your experience is not universal.

Re: A successful Japanese trial of a ramjet engine designed for Mach‑5 aircraft

#102

Post by chrinic6391 »

vkou wrote: post #100
atoav wrote: post #4

The actual time to skim off IMO is all the airport procedures.

This is a solved problem in civilized countries. The time between arriving at an airport and boarding your plane in Japan is ~10 minutes, most of it walking. Because they don't spend an hour fucking around with clownshow security, and because boarding doesn't take forever, as people don't try to stuff ten pieces of carry-on luggage into five overhead bin spaces. Customs always takes time, though, even in the happy (n…

[dead]

Re: A successful Japanese trial of a ramjet engine designed for Mach‑5 aircraft

#103

Post by zardo »

darkteflon wrote: post #6

Cool science. But the article fails to take even a cursory stab at contextualising the plan against the economic, environmental and political backdrop - doesn’t even mention that there’s already been one failed supersonic commercial flight programme. This is as pie-in-the-sky as it gets.

Probably because there is no plan to develop a commercial plane.

Re: A successful Japanese trial of a ramjet engine designed for Mach‑5 aircraft

#106

Post by testing22321 »

Ngraph wrote: post #91

First time I heard the word "ramjet" was as a kid watching the Goliath episode of Knight Rider. Definitely not a documentary, but the word stuck. Then the Blackbird showed up in some plane book, and that was that. Ramjets back in the news. Kid me is having a great morning.

“Roger ramjet he’s our man, hero of the nation!!

https://m.youtube.com/watch?v=E7SqSNQeAFM

Re: A successful Japanese trial of a ramjet engine designed for Mach‑5 aircraft

#108

Post by godelski »

darkteflon wrote: post #78
godelski wrote: post #64

Earlier quoted context omitted.

> This is as pie-in-the-sky as it gets. All your critiques are things we heard about Starlink too. "Oh, you're just reinventing Globalstar[0], which already failed. What makes you think this time will be different?" The question isn't wrong, per say, but most of the time it is used dismissively rather than in earnest. There's thousands of products you use today that were invented and ahead of their time. Hell, Google…

I’m in favour of projects like these - even on spending taxpayer money on them. I think it’s super cool and I would love to see it. Yeah, I also think it’s extremely unlikely. However, when you’re doing journalism, you should contextualise for your readers. TFA doesn’t even try to do the bare minimum.

  > I’m in favour of projects like these - even on spending taxpayer money on them.
Even a few hits is extremely valuable. I mean the US's investments in CERN and ARPA sure lead to way more economic activity and resultant tax money than they ever spent. By many orders of magnitude (I mean the US still is committing like a billion a year, that's nothing in government money. Let alone considering how many multi-trillion dollar companies there are?)

  > However, when you’re doing journalism
Which is why I say the questions are fair and to not use them dismissively. I agree, context matters.

Re: A successful Japanese trial of a ramjet engine designed for Mach‑5 aircraft

#110

Post by phire »

Is a Mach-5 passenger aircraft actually the goal of this project?

Seems more likely that Japan is designing this engine for a hypersonic cruise missile program, and the passenger aircraft concept is somewhat of a cover.

IMO, there is no point in a Mach-5 Aircraft (other than cruise missiles). There is potentially some point in Mach 2-3 aircraft, (not that we have ever made them commercially viable) but at the boundary to hypersonic, you might as well just switch to a suborbital hop concept.

A suborbital hop gets you to anywhere in the world within ~90min, avoids issues of supersonic overflight and you don't need to worry about the massive engineering issues caused by sustaining hypersonic flight. And as a bonus, the passengers get a hour of weightlessness.

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