Some problems for A380...

fokker_f27 · Post by **fokker_f27** » 11 Apr 2006, 11:22

Speaking of cargo aircraft: The A380 might make a great replacement for the Miniguppies if they remove the floor of the second deck.

Bracebrace · Post by **Bracebrace** » 11 Apr 2006, 13:58

For people not knowing the design history of the 747, it's interesting aviation history. Especially the part about the engines and the people thinking it as being too big, unsafe and commercially no chance of survival. Also take a look at the B777 where Boeing had to inject extra tonnes of money to overcome delays due to design problems.

Does it end when gaining the airworthiness certificate? Being a launching customer of a new aircraft is a poisonous marketing thing. Because the aircraft will initially NOT do what is expected. The 747 had engines that drank more fuel than the space shuttle. The 777 caused a lot of delays due to problems (which almost resulted in war between launching customer United and Boeing). You get problems garantied, for free and without warning.

I'm using Boeing examples, but the A380 will be similar. It would be a master achievement if the A380 would finish certification and enter the first 5 years of service without big delays or problems. If the aircraft still has big flaws after 5 years, only then Airbus has a problem.

edwin · Post by **edwin** » 11 Apr 2006, 14:28

i totally agree with you!

look at A380 now its not even passing some tests

smokejumper · Post by **smokejumper** » 17 Apr 2006, 21:50

fokker_f27 wrote:Speaking of cargo aircraft: The A380 might make a great replacement for the Miniguppies if they remove the floor of the second deck.

I believe the floor is a structural support for the fuselage sides; removal, while it will greatly increase volume, might weaken the structure.

TexasGuy · Post by **TexasGuy** » 17 Apr 2006, 22:47

747 drinking more fuel than the space shuttle? a bit dramatic dont you think?

....

Bracebrace · Post by **Bracebrace** » 17 Apr 2006, 23:27

Off course, that's not a real comparison. But it's only to indicate the A380 is doing pretty good so far if you compare it with the development of the 747.

The first versions of the JT9D (the first high-by-pass engine for commercial use) not only had much higher fuel consumptions than expected, but they also had surge problems, and wouldn't survive too long on the wing. Reliability was close to nothing. Some even say there were engines that needed a shop visit (wing removal) after the very first takeoff. The JT9D has been improved after that with new versions, but today still caries a "problem-child" stamp if compared to PW4000 or CF6 alternatives.

If this would happen to the A380 today, no-one would believe it's reliability. Yet that's not the case, and noboby doubts the 747's reliability anymore...

HorsePower · Post by **HorsePower** » 17 Apr 2006, 23:35

smokejumper wrote:I believe the floor is a structural support for the fuselage sides; removal, while it will greatly increase volume, might weaken the structure.

Such an aircraft won't have the main cargo deck pressurised. Therefore, and contrary to what you might read on a certain other forum, it is technicaly perfectly feasible. Even more, I can tell you Airbus have such a project sleeping somewhere -most probably based on the -800R version- to replace the Beluga when time for retirement will arrive.

Regards

Seb.

boeing797 · Post by **boeing797** » 18 Apr 2006, 21:08

Bracebrace wrote:Off course, that's not a real comparison. But it's only to indicate the A380 is doing pretty good so far if you compare it with the development of the 747.

Right. But 30 years ago Boeing engineers designed B747 with papers, pens and primitive calculators (leave alone desktop computers). Today engineers have all kinds of tools that make their jobs easier. It is no surprising A380 program is running smoother than the old B747 did.

Just my thought.

PYX · Post by **PYX** » 19 Apr 2006, 02:57

The 747 was done with pencil, paper, slide rules and little else, and went from scratch to first flight in 16 months. I believe certification only took another 10 months. Which makes one wonder why, with today's computers and "modern manufacturing methods" it takes 4 or 5 years or longer to get a new design into the air.

TexasGuy · Post by **TexasGuy** » 19 Apr 2006, 04:11

PYX wrote:The 747 was done with pencil, paper, slide rules and little else, and went from scratch to first flight in 16 months. I believe certification only took another 10 months. Which makes one wonder why, with today's computers and "modern manufacturing methods" it takes 4 or 5 years or longer to get a new design into the air.

Does make me wonder..............

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Bracebrace · Post by **Bracebrace** » 19 Apr 2006, 11:18

boeing797 wrote:Right. But 30 years ago Boeing engineers designed B747 with papers, pens and primitive calculators (leave alone desktop computers).

A fact and correct.

boeing797 wrote:Today engineers have all kinds of tools that make their jobs easier.

That's a thought.

I'm not pro Airbus, nor pro Boeing. I don't like to compare both companies because thoughts always tend to overrule facts.

Computers don't make the design process easier, they make it possible to take more factors into account. The design process itself has become a lot more complex. Designing the 747 was a matter of creating an aircraft that would do the job. Today the process itself is a lot more complex. Computers allow more factors to be taken into account, which makes it possible to create higher design standards. The job is not easier, the design job is a process run on a higher level (valid for Airbus and Boeing!).

If computers have evolved, so has knowledge. Safety analyses has evolved making the A380 systems much better checked for fatal errors than the first 747 (theoretically), maintenance programs have evolved as well because airlines demand easy maintainability (the 747 was the very first to get a maintenance program based on the first MSG analyses, these analyses have been changed over the years as well).

And to be correct: the 747 is a commercial evolution of a previous design by Boeing, that had to compete with Lockheed (the latter won, ending up with the current C-5 Galaxy). It took 16 months from the launch of the commercial version to the first flight. Hardly comparable with "16 months from scratch".

Once again, I'm not pro Airbus, nor pro Boeing. I simply don't see any reason to doubt the A380 if you don't doubt the 747...

SAS_MD80 · Post by **SAS_MD80** » 19 Apr 2006, 19:32

Exactly, the 747 was the losing aircraft in the large transport aircraft competition of the late 60s. Good someone remembers that. At the time the DoD made its choice between the contenders the aircraft development was nearly finished and had been financially supported to a great extent by the DoD...
Chris

TexasGuy · Post by **TexasGuy** » 19 Apr 2006, 20:29

I am very PRO AIRBUS and VERY PRO Boeing. I think it is healthy to have competition, it helps ensure the consumer has the best product. I love this competition especially, since the 2 players are members of free countries

This is awesome, and i look fwd to both companies creating better aircraft in the future. That being said, i wonder when we will see the A380 here at IAH. We have plenty of space for it here

:):)

.....

PYX · Post by **PYX** » 20 Apr 2006, 03:12

SAS_MD80 wrote:Exactly, the 747 was the losing aircraft in the large transport aircraft competition of the late 60s. Good someone remembers that. At the time the DoD made its choice between the contenders the aircraft development was nearly finished and had been financially supported to a great extent by the DoD...
Chris

Sorry, simply Not so.

From Joe Sutter, the "Father of the 747,"

"I should add that fostering large high-bypass engines was all that the USAF C-5 competition contributed to the Boeing 747, as my new airplane would be called. Time and again there appears in print the logical but false assumption that Boeing took its losing military C-5 bid and revamped it as the commercial 747. In fact, the 747 would be an entirely original design that owes nothing to the C-5."

The story here:
http://seattlepi.nwsource.com/business/ ... air25.html

I believe the book will be published next month.

boeing797 · Post by **boeing797** » 20 Apr 2006, 05:06

Bracebrace wrote:
boeing797 wrote:Right. But 30 years ago Boeing engineers designed B747 with papers, pens and primitive calculators (leave alone desktop computers).
A fact and correct.

boeing797 wrote:Today engineers have all kinds of tools that make their jobs easier.
That's a thought.

.

If you asked engineers in all fields they would say computer aided design does make their jobs easier, engineers more productive, and better products. And if you are an engineer you know it yourself.

Bracebrace wrote:
Computers don't make the design process easier, they make it possible to take more factors into account. The design process itself has become a lot more complex. Designing the 747 was a matter of creating an aircraft that would do the job. Today the process itself is a lot more complex. Computers allow more factors to be taken into account, which makes it possible to create higher design standards. The job is not easier, the design job is a process run on a higher level (valid for Airbus and Boeing!).

If computers have evolved, so has knowledge. Safety analyses has evolved making the A380 systems much better checked for fatal errors than the first 747 (theoretically), maintenance programs have evolved as well because airlines demand easy maintainability (the 747 was the very first to get a maintenance program based on the first MSG analyses, these analyses have been changed over the years as well).

And to be correct: the 747 is a commercial evolution of a previous design by Boeing, that had to compete with Lockheed (the latter won, ending up with the current C-5 Galaxy). It took 16 months from the launch of the commercial version to the first flight. Hardly comparable with "16 months from scratch".

Once again, I'm not pro Airbus, nor pro Boeing. I simply don't see any reason to doubt the A380 if you don't doubt the 747...

True that the design process gets more complex but some of the jobs engineers are doing today are not much different than engineers did 30 years ago. For example, designing the wings. In the old time engineers had to do calculations by hands, build the wings, tested in a wind tunnel. The prototype didn't perform well, they had to go back to the drawing boards, redesigned another prototype, and tested again. They had to keep doing many iterations to achieve the design requirements. Today engineers can build the wings, test, rebuild and retest with CAD. Their first prototype tested in wind tunnel can be very close to the desired goal thanks to super fast and accurate and virtually error free computations done by computers.So after a few iterations they can hit the target. Does computer make engineering jobs easier? How easy is it engineers in the old time had to design millions of parts, and tried to make them fit nicely in an airplane without computers?

So to say A380 program is expected to run better than B747 isn't exaggerated.

2 cents

smokejumper · Post by **smokejumper** » 22 Apr 2006, 00:38

SAS_MD80 wrote:Exactly, the 747 was the losing aircraft in the large transport aircraft competition of the late 60s. Good someone remembers that. At the time the DoD made its choice between the contenders the aircraft development was nearly finished and had been financially supported to a great extent by the DoD...
Chris

The 747 was not the losing design for the C-5A contract; rather it stemmed from that effort. In 1961 several manufacturers began design studies for a large logistic jet transport to deliver payloads of about 140 tons (280, 000 pounds) over long distances and operate from minimally prepared airfields. These efforts required a large plane with the ability carry heavy cargo (tanks, etc.) long distances and off-load directly onto the ground. To do so, required a high wing and much structural strength to minimize the height off the ground. Lockheed won the contract with the C-5A.

Boeing realized that there was a market for a large commercial plane and designed a large passenger plane that could (with new design features) also carry large commercial freight loads. To expedite loading, they designed the plane so the front visor could be raised and large loads loaded straight in. They raised the cockpit above the floor and then streamlined the top of the plane with the 747’s characteristic top shape. Obviously, some of the design work for the C-5A contract was valuable, but not all of it.

This is important since the 747 was an entirely new design that did borrow from the previous experience.

smokejumper · Post by **smokejumper** » 22 Apr 2006, 02:23

HorsePower wrote:
smokejumper wrote:I believe the floor is a structural support for the fuselage sides; removal, while it will greatly increase volume, might weaken the structure.
Such an aircraft won't have the main cargo deck pressurized. Therefore, and contrary to what you might read on a certain other forum, it is technically perfectly feasible. Even more, I can tell you Airbus have such a project sleeping somewhere -most probably based on the -800R version- to replace the Beluga when time for retirement will arrive.

Regards

Seb.

In referring to “structural rigidity” when considering the A380 freighter, I had in mind that the fuselage requires cross-member support (in this case, the floor) to maintain the rigidity of the fuselage, regardless of pressurization. I do not believe that it is feasible, unless some other way to maintain the fuselage’s integrity is designed. Of course, I am not privy to the design calculations made by Airbus.

PYX · Post by **PYX** » 22 Apr 2006, 04:43

One more time:

From Joe Sutter, the "Father of the 747,"

"I should add that fostering large high-bypass engines was all that the USAF C-5 competition contributed to the Boeing 747, as my new airplane would be called. Time and again there appears in print the logical but false assumption that Boeing took its losing military C-5 bid and revamped it as the commercial 747. In fact, the 747 would be an entirely original design that owes nothing to the C-5."

The story here:
http://seattlepi.nwsource.com/business/ ... air25.html

Please note the last line, "In fact, the 747 would be an entirely original design that owes nothing to the C-5."
Get it?
"...OWES NOTHING TO THE C-5."

Of course, one can choose to ignore Mr. Sutter, which must mean those who do so were there and know something Mr. Sutter does not?

SAS_MD80 · Post by **SAS_MD80** » 23 Apr 2006, 01:01

What the hell do you think gives you the right to use such a tone? Your visible exasperation does not exempt you from elementary politeness.
Thanks.
Chris

earthman · Post by **earthman** » 23 Apr 2006, 01:54

They didn't use the design, but no doubt they used the experience from making the C-5 design!