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The Boeing 747 begins its final descent

theatlantic.com

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Re: The Boeing 747 begins its final descent

#361

Post by eichin »

microgpt wrote: post #239
eichin wrote: post #191

Earlier quoted context omitted.

I had a round trip BOS↔LHR that was 747 eastbound, 777 westbound; I ended up on the upper deck of the 747, which was fascinating as an otherwise casual flyer. One especially memorable bit was landing - you're basically three stories up and suddenly the wheels are on the ground, and you're still three stories up :-) (I'm still happy to have traded that for planes with a much higher cabin pressure-altitude - and would…

A higher pressure-altitude or a higher pressure? Can't imagine what's good about a higher pressure-altitude. Less creaking making you less worried the plane will explode?

Higher cabin pressure, but it is marketed in pressure-corresponding-to-altitude; Norwegian Airlines for example keeps their cabins at 6000ft, ie. equivalent atmospheric pressure to being at 6000ft. (Looks like "equivalent effective cabin altitude" or just "cabin altitude" is the more accurate term.) So yeah, I worded that backwards, higher pressure, lower altitude, is more comfortable for passengers (me) especially on longer flights.

Re: The Boeing 747 begins its final descent

#362

Post by wolvoleo »

Rover222 wrote: post #326
wolvoleo wrote: post #127

Earlier quoted context omitted.

Not American but I feel the sentiment. I'm planning to change nationality soon as 'my' own country is also on the same right-wing conservative track. I'm not interested in making things better anymore. I just want to break with them forever. They deserve no more admiration or loyalty. I don't believe in national pride or even of sports teams. My loyalty is always conditional, as long as my ethics align. I can imagine…

I think labeling all things right-wing as bad is part of the problem. The left goes too far, and pushes people to the right. That's why Trump got back into power.

It is because it is all bad at least to me.The right has crossed so many red lines for me that it's just no longer possible to work with them.

Re: The Boeing 747 begins its final descent

#363

Post by panick21_ »

rootusrootus wrote: post #94
Rover222 wrote: post #92

Earlier quoted context omitted.

Glad to see your sentiment. I’m so tired of the reflexive self flagellation of a lot of Americans. It’s often based in ignorance.

It is very tiring. I get why Europeans might enjoy taking shots at us (though at one point I'd have said it was more of a good natured ribbing, given that Europe's history is also many Americans' history), and I fully understand the armies of bots spreading invective ... but the constant dogging on America by our own citizens is sad. I'm sure a lot of this outcome is intentional, but nobody fights back. America is ma…

I feel like this partly a counter reaction. To some US people endlessly glazing the US and endless saying 'best country'. In general the attitude in the US seems to think that anything not rooted in US experience is bad. You can literally feel audience stop listening when somebody giving a speech says 'In X country they do Y because its better based on Z analysis'. And then you have an army of Americans show up telling every possible reason (no matter how irrelevant) why X country is not like the US at all.

I feel like in Europe its much more normal to say, Switzerland is doing X very well, Sweden is going Y very well and so on. Or even the US is doing Z better.

Re: The Boeing 747 begins its final descent

#364

Post by stouset »

scrumper wrote: post #306
stouset wrote: post #263

Earlier quoted context omitted.

Which is not and never will be an issue for airliners transiting oceans under ETOPS.

It is at takeoff and landing, applies equally to ETOPS or otherwise.

> I hate all the justifications used to fly long distances across oceans with only 2 engines, or only 1 engine.

Which is why I specified that it’s equally as safe for airlines operating under ETOPS.

Re: The Boeing 747 begins its final descent

#366

Post by lucumo »

Forgeties79 wrote: post #288
lucumo wrote: post #279

Earlier quoted context omitted.

> When I’m in DC I swipe a card, walk on, walk off. Same with New York and Amsterdam. Even Netherlands into France is walk on/walk off What train did you take to France? Everytime I go to Belgium I have to be careful to pick a train that doesn't require me to book a ticket on a specific train. I really like the "I'll get the next train whenever I reach the station" that domestic trains have. For long distance interna…

Eurostar. Buy tickets online, walk up to gate, QR code beeps on a little scanner, walk onto train. That was it. No TSA-like security experience, no person checking anything (except one guy who walked around on the train and scanned one ticket which registered all our tickets at once, pretty uneventful). UK is a notable exception but they’re also kind of insane about government surveillance/security, especially post-b…

Oh, okay. I misunderstood what you meant by walk on/walk off.

I find the exact planning ahead of time more annoying than a security checkpoint, so was hoping you found a better solution.

Re: The Boeing 747 begins its final descent

#368

Post by fransje26 »

dotancohen wrote: post #353
fransje26 wrote: post #280

Earlier quoted context omitted.

Slightly pedantic, but this is not completely correct. It had a lower Cd with the extended hump, but it still had a higher drag, due to the larger wetted area.

Could you expand upon that for us interested laymen?

Ah. It was based on a series of performance graphs from Boeing, dating back to my aircraft-design days where that very question was discussed and I was baffled enough by the contradiction to ask for detailed clarifications to the presenting professor.

Unfortunately, I don't have access to those old notes, and couldn't quickly find what I was looking for online.

So for now, due to lack of proper supporting arguments, I would say: scratch that.

The Cd is normally normalized by the wing area, and the wing planform was the same between the 747-200 and 747-300. So if the Cd was lower for the -300, the total drag should be assumed to be smaller.

Re: The Boeing 747 begins its final descent

#369

Post by fransje26 »

buildsjets wrote: post #348
fransje26 wrote: post #278

Earlier quoted context omitted.

> I would have to imagine that the newer 747-8 would have the much lower pressurization Two small corrections: 1) If it would have had a change in internal pressurization, the -8 would have a higher pressurization to allow for a lower cabin altitude pressure. 2) The -8 does not have a higher pressurization, because they did not change the fuselage construction. Newer airplanes have lower cabin-altitudes thanks to the…

The -8 also has a lower maximum certified altitude than the -400. The -400 can go to 45,100 feet, the -8 is limited to 43,100 feet. This is actually because the -8 wing is MORE efficient than yhe -400. There is a regulation that in case of a pressurization failure the airplane has to be able to descend below 15,000 feet in a certain time. The -8 wing has less drag, so it is easier to overspeed in descent, and they ha…

Interesting! I did not know that, thanks!

Re: The Boeing 747 begins its final descent

#370

Post by schainks »

rsynnott wrote: post #271
schainks wrote: post #133

Earlier quoted context omitted.

The US was still very much involved in its development and testing, so I think we can still chalk it up as a win for multi-country collaboration, eh :3

> The US was still very much involved in its development and testing ... Wait, how was that? The Concorde was essentially the Franco-British entry in what was once a rather fierce international race to build a supersonic passenger jet (then seen as the future); the US entries were the (failed) Lockheed L-2000 and Boeing 2707. If the US had been open to collaboration, it is likely that the UK would’ve gone in with the…

Jeez it's on the Wikipedia page, not sure why you wouldn't consider these things "direct involvement":

- NASA Skylancer built to validate wing design and improve landings.

- NASA simulations at Ames that predicted ground effect pitch issues that was incorporated into pilot training.

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