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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

#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.

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

#92

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.

Concord was very old technology. I am quite sure a clean sheet now

1. Would have much lower sonic booms thanks to recent research (quite a bit of it by NASA on wing geometry) and more importantly computer simulation available now

2. The engines would be far more fuel efficient

3. The flights would be able to have better efficiency in the subsonic regime as well. Just see what winglets and the like have done to fuel economy .

I fly 14 to 18 hour routes maybe 4-5 times a year on business paying 5x the economy cost and it still sucks. Breaking the flight with a connection (IMO) sucks more. My management flies such routes every month. There is a lot of revenue headroom in that fare gap for something that flies maybe 3x-4x as fast which military aircraft already do.

What will hold back the idea is conservatism among the business managers in aircraft manufactures and incumbent airlines who will "draw lessons" from a 50 year old experiment

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

#93
post #43

Earlier quoted context omitted.

What are some examples of employees so important you would pay $100k to get them somewhere immediately?

You are not thinking high enough the food chain. I mean heck you have tenured SV engineers cracking $1mm with RSUs. It’s not rare in finance for folks to be hitting $3-5mm with bonus. So that’s what $19k comp a day. If that individual is making $5mm they are more than likely making a multiple of that for the organization.

Well yea great but why do they have to be there so quickly that not even a private jet is good enough?

What kind of multi million dollar deal blows up because a dude arrives 18 hours later? And what are they doing when they get there that couldn’t have been done online?

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

#94

Earlier quoted context omitted.

I think a lot of the Concorde failure is tied to its status as a British-French project. Trans-Pacific flights are much longer and there's a lot of money in PEK -> LAX than in JFK -> LHR. Qantas wanted to offer London to Sydney, but they couldn't fly supersonic over land. Mainland China or Japan to Australia is a feasible route for high-margin, low-capacity supersonic flights. If you could make the flight from Beijin…

It's not tied to anything other than there not being enough people who care enough to spend the sort of money required. The people who have that kind of money are going to be more interested in flying in a jet share doing mach .96 leaving when they want to leave, going where they want to go, when they want to go, how they want to go, with who they want to go with. You get treated like a criminal for forgetting your s…

> You get treated like a criminal for forgetting your shampoo bottle is 2 ounces too big for some dipshit TSA agent's liking,

Enforcement is super uneven, and etc, but IME, they just open your bag, find the thing, and then offer you the choice of tossing it or going back to check your bag. Depending on how much you paid for your shampoo and how much a checked bag would cost you and if you have time to do all that and then wait in line again, I expect most people toss it.

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

#95
post #66
post #4

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

Really? Obviously it varies by country, but there’s no customs/immigration when leaving the US, and security usually takes <5 minutes with PreCheck. Sometimes immigration takes a while on the other side, but it’s quick at airports with biometric gate systems. You still hear people talk about airport buffer time in units of hours, but I think that’s increasingly out of date.

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 thing entirely.

Yes, domestic or international matters. Yes, flying business class makes it faster. Yes signing up for "special status" makes things faster.

But airports are typically some drive away from city center (both ends, in traffic). Security and immigration both take time (often significant time.) Door to door time is easily 6 hours more than flight time.

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

#96

Interesting, but assuming they can get the engine to work as intended, the question still remains how the passenger jet would get up to Mach 5 so the engine can start working. A solid-fuel rocket booster that would then drop off?

It is a safe bet that the first applications will be missiles and there won't be any passengers to worry about.

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

#97
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.

Yes it looks a lot more cheesy now than I remember as a kid

https://youtu.be/SpEO-jIKhE8?si=89Qw1_AOXYow9PfR

But ramjets have been promised to us for years

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

#98

Interesting, but assuming they can get the engine to work as intended, the question still remains how the passenger jet would get up to Mach 5 so the engine can start working. A solid-fuel rocket booster that would then drop off?

It is a safe bet that the first applications will be missiles and there won't be any passengers to worry about.

Interns provide the guidance.

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

#99
post #66

Earlier quoted context omitted.

Really? Obviously it varies by country, but there’s no customs/immigration when leaving the US, and security usually takes <5 minutes with PreCheck. Sometimes immigration takes a while on the other side, but it’s quick at airports with biometric gate systems. You still hear people talk about airport buffer time in units of hours, but I think that’s increasingly out of date.

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 and still make it to the gate with plenty to spare.

On international returns, both Global Entry or MPC lines are virtually empty when I arrive (SFO)

The worst part is international arrivals in foreign countries, where immigration can soak up a lot of time, and you have no choice but to stand in line. Luckily I don't have to fly internationally too many times a year.

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

#100
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 (no extra questions, no bag searches) path.

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Do you want to know the secret to fast security lines?

Either reduce the work security does, or open more lines and hire more agents[1], until they can meet the throughput requirements. Both seem to be anathema to an American airport.

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[1] This also works to reduce lines and improve quality and cleanliness in other aspects of society. It's not that Japanese people don't produce any garbage, or dirt, it's that their public infrastructure is regularly and meticulously cleaned and maintained.

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