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Comment by avar | Hacker News Reader

For anyone wondering why airlines are retiring the 747 this Wikipedia section summarizes it: https://en.wikipedia.org/wiki/Boeing_747-400#Retirement_and_...

Summary: Old, inefficient, less need for jumbo jets. Everyone's either buying smaller or migrating to the modern Airbus A380.

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The A380 isn't that popular either. The A380 only makes sense for really popular routes with a guaranteed high passenger count, whereas the 787 is more flexible because it has a similar range and takes less passengers but is almost as efficient per passenger-mile.

And in 2016 there were fears Airbus might even cancel the A380 entirely: https://qz.com/782361/airbus-a380-airlines-are-abandoning-th...

> The A380 isn't that popular either. The A380 only makes sense for really popular routes with a guaranteed high passenger count, whereas the 787 is more flexible because it has a similar range and takes less passengers but is almost as efficient per passenger-mile.

Also with airports where you're slot limited, and hence operating a single aircraft is easier.

This is why they fly the 380 for some domestic flights (e.g. Beijing to Guangzhou). The only one I've been on actually.

To an extent, but Ba don't use the a380 on Heathrow to New York, despite being one of the busiest long haul routes and LHr (and I assume JFK) being full. High profit passengers value the near hourly service.

They use them on long routes with low frequency but lots of connections - singapore, Joburg, LAX.

A380 definitely works for hub and spokes though - emirates run about 10 a380 flights to the uk every day.

The A380 was a bet on hub-and-spoke (Emirates is the biggest A380 operator, with all flights going to/from Dubai), while the B787 was a bet on point-to-point.

I know which model I'd rather go with as a passenger...

Yup, Wendover Productions (massive aeroplane nerd) did a fanatastic video about this, really recommend it if anyone's interested in the economics of airlines.

https://www.youtube.com/watch?v=HSxSgbNQi-g

That whole YouTube channel is awesome, and there are a few related ones that are also fantastic.

I agree. Also wanted to add a bit more color. When I did my MBA, we visited Emirates, and I heard a cool story. Apparently, international airports limited the landing slots that Emirates could use. Emirates then pushed Airbus to create the A380 so they could maximize passenger volume per landing slot. I'm sure this is only part of the story, but it's a pretty cool angle and a creative response to a business reality :)

I think high-efficiency twins and ETOPS (https://en.wikipedia.org/wiki/ETOPS) standards certifying twins for transoceanic flights have contributed to the reduced demand for four-engine jets.

I will miss the B747 (and yes, I love airplanes).

They might not be popular with the companies, but I flew regular cattle-class on a 380 to Dubai and it was better than premium economy on some 747s.

Remember that Boeing's original plan was to use the 747 as a freighter. Passengers would fly on supersonic jets like their prototype 2707 SST.

This is why the 747's cockpit is on top, it provided a continuous open tube for cargo underneath.

http://www.nycaviation.com/newspage/wp-content/uploads/2015/...

Has there ever been a flying wing approach to freight flights?

There have been proposals. Here's the Lockheed Spanloader concept.[1] Never built. The idea comes around again every once in a while.[2]

[1] https://books.google.com/books?id=jWlaIWwcsiwC&pg=PA112 [2] https://books.google.com/books?id=C0gUyoYewhoC&pg=PT183

The trouble with flying wings is the fuselage tends to be too short for carrying a lot of cargo. You can't put heavy cargo outboard in the wings because then it's tough to balance the load and the high rotational inertia makes roll control difficult.

Flying wings work fine for bombers because the "cargo" is very dense and will fit into a short bomb bay.

> Remember that Boeing's original plan was to use the 747 as a freighter.

You have to wonder actually if that is even true (I've heard it as well obviously). Reason being Boeing may have been thinking SST wouldn't work or be practical (after all it wasn't) but it was easier to sell a 747 based on saying it could be used as a freighter primarily. If they had said it was just another long range high capacity plane the project might have never gotten approval because of the 'bet the company' risk.

No-one could say it was just another long range high capacity plane, as there was nothing comparable. And at the time, Boeing was spending a lot of money on a specific Mach 3 SST project - it was only later that it concluded that it wasn't feasible.

The upper cockpit is a huge aerodynamic drag compared to previous designs.

Perhaps the 747 was a hedge (and it turned out to be a good one if so), but the design kind of implies otherwise IMO.

There are, of course, Boeing 747 freighters. [1]

[1] http://www.boeing.com/commercial/freighters/

The form of a 747 is the result of technology studies for the Air Force CX-HLS program

http://www.boeingimages.com/archive/CX-HLS-Transport-Study-2...

That and the fact that to be legal to fly in the US (possibly elsewhere) as of 2018, they'll need an expensive fuel tank inerting system retrofitted.

This was interesting, thanks. For others: "inerting" is process of keeping fuel tanks filled with inert gases like nitrogen to decrease the change of a fuel tank explosion.

https://en.wikipedia.org/wiki/Inerting_system

Have been talked about for many years, but became a formal rule only recently.

https://www.ainonline.com/aviation-news/aviation-internation...

Why is this necessary. I take it 747s have been safe up til now?

The reason the FAA considered fuel tank inerting in the first place is because of a 1996 crash of a 747 that killed 230 people[1], and which is thought to have been avoided had the tanks been inert[2]. Other 747s were lost to the same issue, such as the ULF48 that crashed in 1976 killing all aboard[3].

To answer your question, no, the 747 is not "safe". No aircraft ever made is "safe". They will all crash and kill people given sufficient flight hours. The question is what we consider acceptable risk, those standards change over time as technology improves, and as regulators phase out older models by sunsetting certain exceptions.

As that's done older aircraft either need to be retrofitted, or sold to jurisdictions with laxer rules.

1. https://en.wikipedia.org/wiki/TWA_Flight_800

2. https://en.wikipedia.org/wiki/Inerting_system#Aircraft

3. https://en.wikipedia.org/wiki/Boeing_747_hull_losses#1970s

I hadn't read the Wiki article about inerting systems up until now. It's interesting to me that the prediction is interting systems will prevent 8 of 9 expected wrecks in the next 50 years.

I'd argue that modern aircraft are safe especially after you factor in how many hours these things fly compared to the number of deaths. Of course, air travel has become significantly safer over time. Check out the early history of 727 hull losses. While the 747 had a number of poor designs (especially early on), the deadliest 747 wrecks were due to pilot error (e.g. Tenerife).

Theres a lot of speculation about TWA Flight 800 so thats pretty interesting. I some how stumbled on CPAN one night and the guy that wrote TWA 800 Crash Cover Up Conspiracy was giving a talk. Listening to the commenters afterwards, all were either engineers, pilots, or former air force and seemed to be in agreement with the author. Theres a TWA Flight 800 documentary as well.

book: https://www.amazon.com/TWA-800-Crash-Cover-Up-Conspiracy/dp/...

movie: https://flight800doc.com

> I some how stumbled on CPAN one night and the guy that wrote TWA 800 Crash Cover Up Conspiracy was giving a talk.

I think you mean C-SPAN. Unless the more nefarious of the Perl hackers have been working overtime. :)

So what. You can find more engineers and pilots who don't believe it was a conspiracy. The human mind tends to invent patterns where none exist in a vain attempt to make sense out of chaos.

I appreciate your answer and the informative links.

    No aircraft ever made is "safe". They will all crash and 
    kill people given sufficient flight hours. The question 
    is what we consider acceptable risk,

Let's give our fellow HNers a little credit, shall we?

When the other poster asked if 747s were "safe," do you really think they meant to ask if 747s were literally indestructible? Or do you think the other poster meant "safe" as in "safe, compared to other aircraft, which are things that any reasonable human being understands can have accidents from time to time?" I really believe it was the latter.

Nobody thinks airplanes are indestructible, but it is counteractive to those not familiar with commercial aviation that not only is the market for licensing new airframes regulated, but that older airframes are expected to be retrofitted to the latest safety standards or lose their license.

This isn't how e.g. trains, buses and even taxis are regulated. E.g. I believe in most of the western world you could still operate an antique car without seat belts as a taxi.

This is how I read the GPs comment of "I take it 747s have been safe up til now". The only way the bus/train/taxi in my example would lose its license is if it could be shown if the vehicle didn't adhere to the safety standards at the time, whereas the same isn't true for airplanes at all due to how the FAA & EASA regulate them.

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