Saturday, January 22, 2005

 

Mandatory Comment On The Airbus A380

I'm not exactly an aviation buff, and certainly not of civilian aviation (at least not since sometime in junior high). As such, take what I'm about to say with a big grain of salt. The A380 is being portrayed as some sort of engineering breakthrough, and so I figured that a bit of investigation is due. Does this present a significant advancement in the art of aerospace engineering, and will it eventually result in the decreased operating costs that airlines crave?

My first thoughts on this aircraft is that it's little more than a scaled-up variation on the 747 theme, incorporating fly-by-wire technology (which is now well over 20 years old) and hopefully some material advancements. And that appears to be the case, at least with the data I've found.

The only noteworthy feature from a performance standpoint is the increased ratio of gross take-off weight to wingspan, which is driven by the need to accomodate ever-increasing average per-passenger weights (a result of longer flight distances and larger waistlines), and the limitations of most airports. What's the effect of this? Well, it would appear that one issue is an increase in drag (page 7). Uh-oh - a 22% increase in drag from the "optimal" configuration is not likely a step in the right direction. That's probably not going to help with reducing operating costs, although Airbus still claims a 13% improvement over similar aircraft.

In terms of the engineering itself, any improvements are likely to come in the form of advanced materials (the assumption being made here that fly-by-wire systems are developed to a mature state). Here, there does appear to be something of merit. The "wing box" structure, along with the entire tail assembly, is made of carbon-fiber composite (although not much information is given as to the resin used in this material). The wing leading edges are also a composite of some sort. The upper portion of the fuselage is constructed of an aluminum/composite lamination, yielding a weight savings of approximately 10% over standard aluminum, and an unspecified improvement in fatigue life. Where standard aluminum is used, laser welding is employed for attachment as opposed to standard riveting techniques. All in all, it's claimed that this material has resulted in a weight savings of 10-15 tons in the 240-ton aircraft. Impressive, but is a 4-6% improvement over the past 25 years really anything amazing? I feel somewhat underwhelmed by this pace of development.

Ultimately, though, the question will come down to passenger preferences, in terms of how they want to fly - from point-to-point between smaller airports, or hub-to-hub with commuter flights to the end destination. The head of Boeing has his own opinion on this (damn, everyone's blogging nowadays), and he backs it up with some data:

Consider that Airbus says London's Heathrow will use the most A380s during the
next two decades. Yet, the 747's share of departures at Heathrow hasn't changed
during the past twenty years. Airbus lists Tokyo's two airports and Hong Kong's
as major A380 hubs. But at those three airports, the 747 as a percentage of
departures is about half of what it was in the 1990s. If large airplanes solve
congestion, the 747 departures would have been going up.


Either Airbus knows for certain that the trends of the past 10 to 15 years are about to do an immediate U-turn, or it has misread the state of aviation as it really is today and where it's going in the future.



Interesting point.

Everything considered, I think the A380 is merely a minor improvement on the decades-old 747, and perhaps indicates that commercial aviation as we know it has stagnated, much as the ocean-liner industry had around the time of the Titanic, and will remain so until we see some sort of a push towards near-space hypersonic transport. Given the cost pressures currently exisiting in the industry, that's likely a long ways off, but maybe Burt Rutan's accomplishments with SpaceShipOne someday be viewed as the event that kicked into motion the next generation of transportation development. After all, it did take nearly 50 years for the Wright brother's flight to mature into something affordable for the masses. Or maybe instead we'll get affordable personal aviation, made possible by the technology employed in the automotive world.

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