Boeing 747 turns 35 Years Old

gad Bob- talk about throwing gas on flame wars...

reality says that very few things are great engneering leaps forward -
indeed, virtually everything builds and expands on what came before -
aviation itself as an example - did man fly before Wright? Of course,
balloons, gliders. So what was Wrights' major contribution? System
integration. A lightweight engine coupled to a glider with their
observation of "wing warping" for roll stability as the major (as in "not
seen before") contribution. jet engines? The gas cycle had been
demonstrated before, just that the IMPLEMENTATION was difficult if not
impossible until all the pieces were put together.

Soooo... 747 as an "engineering marvel" is only true IF you look at the
event as happening in a vacuum. Similarly Concorde...for the same reasons

So what was it that made Concorde's engineering "special"? After all,
supersonic delta winged aircraft were't exactly uncommon (in the military)
and Concorde is a scale up. 747 groundwork was based in major part on C-5
design (lost competition to Lockheed - or we might have had the "L-1111"
which would have taken the same path as Boeing did when Boeing lost the C-5)

"Bob Myers" wrote in message
...

"AES/newspost" wrote in message
...
I've posted the controversial assertions above before, admittedly in a
kind of "throwing gasoline on the flame wars" mode, because I think
great *engineering* accomplishments (as contrasted to purely
technological showoff displays) should include most or all of the
factors:

1. Meet a real and significant human need; make the world a better
place.

2. Do so with examplary energy and economic efficiency, given the state
of the art in their time.

3. Ditto for their environmental impact.

4. Do it with acceptable safety.

OK, I think I can see where you're coming from on this, but given
the above criteria, how would you rank something like, say, the
Apollo/Saturn spacecraft? The "real and significant human need"
part of that could be open to a huge debate; #2 (energy/economic
efficiency) wasn't really a part of the design goals. I could argue that
the environmental impact was a relatively minor concern (no one
ever expected that there would be more than a handful of Saturn V
launches, total - it's not like designing a nationwide transportation
system). Was the safety acceptable? Well, we didn't lose anyone
on those missions, although there was certainly one hell of a risk.
I'd still argue that from a strictly "engineering accomplishment"
standpoint, going from the Explorer I in 1958 to a man on the
moon by mid-1969 was a pretty impressive feat. Sure, it was
essentially an exercise in political grandstanding; still a lot of very
good engineers put in a lot of very good work to make it happen.

When it comes right down to it, you'd be hard pressed to place
ANY aviation-related achievement in the "significant engineering
feat" category if you adhere STRICTLY to your criteria. After
all, it's not like anyone really HAS to fly...and even today,
RELATIVELY few do.

Bob M.

In article ,
"Bob Myers" wrote:

"AES/newspost" wrote in message
...
I've posted the controversial assertions above before, admittedly in a
kind of "throwing gasoline on the flame wars" mode, because I think
great *engineering* accomplishments (as contrasted to purely
technological showoff displays) should include most or all of the
factors:

1. Meet a real and significant human need; make the world a better
place.

2. Do so with examplary energy and economic efficiency, given the state
of the art in their time.

3. Ditto for their environmental impact.

4. Do it with acceptable safety.

OK, I think I can see where you're coming from on this, but given
the above criteria, how would you rank something like, say, the
Apollo/Saturn spacecraft? The "real and significant human need"
part of that could be open to a huge debate;

Yes, I agree.

Personally (and that's all i claim) I think the Apollo program was a
definitely worthwhile project:

* as a major human accomplishment ("Giant step for all mankind"), even
if not exactly a "human need"

* for the science it did (brought back moon rocks, among other things)
and the thinking and learning and technical development it motivated

* even as a matter of national pride and stature for the U.S. (though
that's definitely the lowest item on my list).

The whole shuttle program, on the other hand, for me anyway, has been a
largely pointless waste. Leaving aside dead astronauts, it was way
over-hyped; never delivered on its promises despite vast cost overruns;
did little or no useful science; and diverted us into technically bad
and politically motivated decisions -- like insisting that the Hubble be
launched with the shuttle, leaving it in an undesirably low orbit, then
justifying this by "repair missions" for which the shuttle launch costs
vastly exceeded what would have been the cost of building and launching
an improved Hubble into a much better orbit using an unmanned vehicle.

Essentially the same points apply to the Orbiting Space Lab, and in
spades to whole idea of putting a man on Mars, which is as unnecessary
as it is technically unfeasable.

"DALing" daling43[delete]-at-hotmail.com wrote in message
...
gad Bob- talk about throwing gas on flame wars...

Well, everyone deserves a hobby, right? :-)


reality says that very few things are great engneering leaps forward -
indeed, virtually everything builds and expands on what came before -
aviation itself as an example - did man fly before Wright? Of course,
balloons, gliders. So what was Wrights' major contribution? System
integration. A lightweight engine coupled to a glider with their
observation of "wing warping" for roll stability as the major (as in "not
seen before") contribution. jet engines? The gas cycle had been
demonstrated before, just that the IMPLEMENTATION was difficult if not
impossible until all the pieces were put together.

Sure - although in those, I would quibble that you're now
concentrating on the aspect of "innovation", as in "invention",
which I would see as not quite the same as just recognizing
engineering "elegance" - to use a much-abused term.


Bob M.

"devil" wrote in message
news
On Tue, 10 Feb 2004 20:44:57 -0800, AES/newspost wrote:


- sip -

Still, just like the Concorde, the 747 more more of a status symbol than
an econimic or engineering achievement. Way too big for the market,
actually. The airlines, which felt they had to buy into the status
symbol, paid the price, in the end.


- sip -

Ever been in Asia?

Nik

On Fri, 13 Feb 2004 08:27:40 +0800, Nik wrote:


"devil" wrote in message
news
On Tue, 10 Feb 2004 20:44:57 -0800, AES/newspost wrote:


- sip -

Still, just like the Concorde, the 747 more more of a status symbol than
an econimic or engineering achievement. Way too big for the market,
actually. The airlines, which felt they had to buy into the status
symbol, paid the price, in the end.


- sip -

Ever been in Asia?

Not in the seventies.

"None" wrote in message
. net...
IMHO, the 7E7 is going to give Airbus some cause for concern. In the very
least, it is going to test their weedles as far as their ability to adapt
and compete goes. While Boeing has been releasing data on the 7E7, you
can
bet they aren't talking about it's deepest darkest secrets/benefits. Time
will tell, and I expect airlines will start placing preliminary orders for
the E by the end of this year if not sooner.


Compared to the Airbus competition - where are the significant savings for
the E going to come from?

Compared to the 767 it's relatively easy to see what can be done. You can
make it FBW and save some weight there, you can introduce more composite
materials and save some more weight. And perhaps it will be possible today
to make a better aerodynamic design. However, the Airbus competition already
is FBW and already has quite a saving due to composites. So what you are
left with doing is introduce more composites and make the aerodynamics
better. But how much can you get here? Where is the new big thing that will
give the E an edge of any significance?


Nik.

On Wed, 11 Feb 2004 05:20:52 -0500, nobody wrote:

devil wrote:
Still, just like the Concorde, the 747 more more of a status symbol than
an econimic or engineering achievement. Way too big for the market,
actually.

I disagree. Plenty of airlnes have made extremely profitable/efficient use of
the 747, and still do.

Way too big for the market at the time. Still way too big for most
markets, but in the end, enough to pay the bills. Came damn close to
bankrupt Boeing though.


The Concorde had no pretense of lowering seat mile costs. The 747
delivered on lower costs per seat.

If you don't put warm bodies on these seats, it still doesn't help, does
it?

And yes, the Concorde was far more an engineering achievement than
the
747. Both structurally (plane expanded significantly due to friction
heating) and the powerplant.

Part or the Concorde problem was that it was always a half-baked thing.
Too small, too short. Too expensive. Started as a medium range plane,
eventually pushed up to the limit to make it barely long enough to cross
the Atalntic, etc. Should have been built of titanium. Should have
seated 150-180 people, perhaps more.

Now we may have a new white elephant on the map. I know, at least,
it's not supersonic...

There are routes for which the 747 and 380 are a better solution than
other planes. And if yor network has enough such routes, that it it
worth buying those planes.

Still won't pay the development costs.

AC may have gotten rid of its former CP 747s,
but it was due to contract stuff. They are refurbishing their remaining
747 combis, and there is expectation that AC may obtain up to 5 747s
once it emerges from bankrupcy.

The Combis, seesm they are keeping, because apparently they nake sesne
because of the freight business. More? Pure freighters then. AKAIK, AC
is going to get the 340s they have on order. Much more suited to their
network.


When you look at the airlines which refused to buy 747s (AA, DL, CO,
US), they are not exactly very healthy. AA sacrificed its efficiency and
lower costs in order to keep it prized heathrow slots, so it needs to
run small planes to LHR every 10 minutes to keep those slots. And you'll
find that all 3 airlines are shut out of Asia /South Pacific because
they lack the 747. In fact, CO had to pull out of the south pacific
because it lacked the 747s.

AA is still the most healthy of the US airlines.

On Sat, 14 Feb 2004 19:11:24 +0800, Nik wrote:


Compared to the 767 it's relatively easy to see what can be done. You can
make it FBW and save some weight there, you can introduce more composite
materials and save some more weight. And perhaps it will be possible today
to make a better aerodynamic design. However, the Airbus competition already
is FBW and already has quite a saving due to composites. So what you are
left with doing is introduce more composites and make the aerodynamics
better. But how much can you get here? Where is the new big thing that will
give the E an edge of any significance?

There may be some room with the aerodynamics. Remember that the 330 and
340 were designed to use the same wing which got to be suboptimal as a
result.

Also, you would think a newer aerodynamic design might be better optimized
anyway. And surely, there must be tons of small things in which there is
room left to lower weight.

devil wrote:
There may be some room with the aerodynamics. Remember that the 330 and
340 were designed to use the same wing which got to be suboptimal as a
result.

Does anyone have authoritative information on this ? I have read the
opposite, and the only people who proclaimed that story were the airbus
bashers back in the days of sci.aeronautics-airliners who had made all sorts
of statements that have proven themselves to be false or irrelevant over the years.

Consider that engines are the heaviest items on a plane and generate a lot of
force that must be transfered to the wing. It is hard to believe that they
could have taken a 2 engine wing and just bolted one engine in a different
location. Location of fuel tanks would have to change, so would have flaps and
slats (as well as the mythical slaps).

nobody wrote in message ...
devil wrote:
There may be some room with the aerodynamics. Remember that the 330 and
340 were designed to use the same wing which got to be suboptimal as a
result.

Does anyone have authoritative information on this ? I have read the
opposite, and the only people who proclaimed that story were the airbus
bashers back in the days of sci.aeronautics-airliners who had made all sorts
of statements that have proven themselves to be false or irrelevant over the years.

Consider that engines are the heaviest items on a plane and generate a lot of
force that must be transfered to the wing. It is hard to believe that they
could have taken a 2 engine wing and just bolted one engine in a different
location. Location of fuel tanks would have to change, so would have flaps and
slats (as well as the mythical slaps).

Flight International, June 5, 1991


The A340 wing is virtually identical to that of the A330. Its design
represents a rare, if not unique, achievement among commercial jet
airliners - a wing which can support either two or four engines.
Airbus claims this is not simply a good engineering compromise, but
also an aerodynamic match that meets the economic cruise requirements
of both the medium-range A330 and the long-range A340.

The A340 wing is the biggest to be designed and built by British
Aerospace for the Airbus family. It has the highest sweep of any
Airbus wing, to accommodate the higher, Mach 0.82-0.84, speed of the
longrange aircraft compared to its predecessors which cruise at M0.80.
At 30 degrees, sweepback is still moderate compared with the Boeing
747's 40 degrees and the McDonnell Douglas MD11's 36.

Although the A340 wing has virtually the same span as that of the
747-200, it has only 65% of the area, a high-aspect ratio having been
chosen to cut both take-off and cruise drag. Span over the winglets is
60.2m and wing area is 362[m.sup.2] (compared to the A300-600's
260[m.sup.2]).

The multi-role wing's secret lies in the neat balance of bending
moments (exerted on the fuselage by the wing) between the twin and
four-engined versions. The A330 and A340 wing bending moments are
within 1.5% of each other, allowing the two structures to be assembled
in the same jigs.

Because of bending relief from the weight of its outboard engines, the
bending moment of a four-engined aircraft is substantially lower than
it is for a twin at the same maximum take-off weight. For the same
fuselage weight, therefore, a twin needs a stronger, heavier wing than
a quad.

It follows that, for the same wing, the payload carried in the
fuselage must be less for a twin than a four, which is exactly what
has happened with the A330/A340: the latter carries about 20% more
payload. This translates to about 30t of extra fuel, giving the A340
its long-range capability and requiring the addition of a
centre-fuselage undercarriage leg. Design strength required was "only
1% higher than the A330", says Jeff Jupp, BAe chief engineer, Airbus.

The wing betrays its A300 structural heritage with a load-carrying
wing torsion box made up of front and rear spars linked by transverse
ribs which support the top and bottom covers. Another feature of the
A300 wing, an inboard centre spar, has been revived to help support
the sheer size of the structure and to accommodate the more stringent
needs for damage tolerance. The centre spar terminates outboard of the
inboard engine pylon.

Although similar in overall arrangement to that on other Airbus
aircraft, the layout of leading-edge slats, trailing-edge flaps,
spoilers and ailerons differs in detail - mainly because of the
engines. Following a change from long slat segments to more, shorter
segments on the A320 (for tighter rigging under load), the same
approach has been followed on the A330/A340 wing.

The wing has seven slats per side with a gap between the fourth and
fifth to accommodate the outboard engine pylon and, for the A330, a
gap between the first and second for the inboard engine. Airbus
estimates that the improved conformity of the slats will eliminate
parasitic drag.

Other changes in control surfaces are evident in the two-section
ailerons. Using the fly-by-wire flight-control system, the ailerons
are drooped for take-off and landing to provide a full-span
trailing-edge flap. The ailerons are also deflected upwards after
touchdown to increase lift dumping and braking efficiency.

As well as being used for roll control, the ailerons deflect upwards
when the inboard airbrake panels are deployed during manoeuvres to
relieve wing bending moments. The A340 does not have an A320-style
gust-load alleviation system, says Jupp. "This wing is much more
manoeuvre dominated...the speed with which the surface needs to react
is that much slower than the A320."

Aerodynamically, the wing is a direct cousin of the A310's and
features the same three-dimensional design, adjusted for the
longer-range missions. Aspect ratio is higher, at 9.3 against 8.8, and
the wingtip devices, canted at around 45 degrees, were included from
the start of wing design, saving an estimated 1.5% on cruise fuel
burn. The Hawker de Havilland-built devices deflect inboard at the tip
by 5 degrees in the cruise.

The most obvious visual difference between the A330 and A340 wings is
the latter's outer engine installation. "We already knew how to put
engines on the inner wing position, but it took us two years to find
out how to do it perfectly with the outboard engines," says Airbus
A330/A340 chief engineer Geoffrey Thomas. "We started off with the
best ideals...which were to satisfy industrial demands by having
common inner and outer pylons." The inboard pylons were already at the
same locations as those of the A330, which were reinforced for the
engines of the twin.

Aerodynamic studies showed that there would be an aerodynamic penalty
if all four pylons were the same. "The A330 pylon would have pushed
the engine too far forward," says Jupp, who adds that the new inboard
pylon pushes the engine 400mm forward to preserve the aerodynamics of
the "crucial gulley" between nacelle and lower wingskin near the wing
root.

Two years of intense three-dimensional computer analysis, coupled with
windtunnel studies, has resulted in the A340 having less wing/engine
interference drag than the twin-engined A310, Airbus says.

To meet damage tolerance requirements, the fuel system layout is
altered to keep collector cells (the aircraft's final fuel reserve
area) out of the potential strike paths of debris from exploding
engines. Collector cells are placed midway between the inboard engine
pylon and fuselage, aft of the inboard engine exhaust and forward of
the outboard engine's compressor line.