atomic_fungus (atomic_fungus) wrote,

#183: Airbus A380's a boondoggle.

More A380 Delays

The airlines which can wait for the over-budget, overweight, and over-schedule plane can expect deep discounts for the delays, but the heavily-subsidized Airbus will naturally have no fiscal troubles--even after selling the massive new airliner for 1/3-1/2 its MSRP. FedEx has already canceled its entire order, instead turning to Boeing.

Airbus is a consortium of European aerospace companies, heavily subsidized by their home countries. It's the only serious competition that Boeing has, anymore; Boeing makes the best airplanes in the world, and just about everyone knows it. Without the heavy subsidies Airbus probably would have gone out of business years ago, but the Europeans know it's in their best interests to keep the concern going...and so it does, despite "little" problems such as a release date that keeps slipping away, just out of reach, like a $20 bill on a fishing line.

I am no fan of Airbus products; on the infrequent occasions that I travel by air I try to ensure I am flying on a Boeing product. (Or a product of one of the corporations that Boeing bought, anyway.) Besides my preference for American products, newer Airbus planes are all fly-by-wire, and the avionics software incorporates something called envelope control.

"Envelope" refers to the operating regime in which the airplane is designed to fly. The job of a test pilot is to verify that the airplane performs as expected within this envelope, and he also attempts to find the limits of that envelope--that is, to see if the designed performance envelope can be exceeded safely, and if so, by how much. The test pilot helps the engineers determine the plane's maximum performance limits and to ensure that the airplane will be safe in as many conditions as possible.

Normally the envelope is defined once all the operating regimes are known; the airplane is assigned performance numbers which are deemed safe and the pilots are instructed (via the manual) not to exceed these numbers. It's up to the pilot not to fly the airplane outside of this envelope, and the pilot understands that if he does venture into this territory, he is outside the envelope and will probably die.

For example, an airplane must never be operated above a certain speed, called Vne or the "never exceed speed". The Cessna 152 can withstand around 6 gravities (g) of acceleration and about 2 negative g of acceleration. And there are many others--speeds at which flaps may be deployed, and by how much; takeoff speeds, landing speeds, maneuvering speeds, and so forth.

With newer Airbus airplanes, though, it is no longer up to the pilot. The avionics software ensures that the airplane can never be stressed beyond any of these numbers. But besides the obvious "hard" mechanical and structural limits, Airbus included "soft" limits--things like engine speed and loading, for example, which were designed to extend the operating life of the engines and other wear components.

That sounds like a very good idea, doesn't it? While it seems to make sense--and while it actually does make sense most of the time--there are times when the man controlling the machine must have full authority...and the Airbus avionics do not have an override switch.

The end result can be disastrous. During a flyby at an air show, an Airbus passenger jet flew down the runway, flaps and gear extended; it maintained an even altitude all the way down, past the end of the runway, into the trees...oops.

Few people died in the crash but the airplane was a total loss. The pilot was found guilty of several crimes and even now is in jail. What went wrong?

The pilot did make some errors: the airplane was too low and too slow. In a conventional airliner the pilot could have added more power than was called for and forced the airplane to climb--he wasn't going that slow; more power would have done it--and he only needed about ten or twenty feet more altitude to clear the trees at the end of the runway. But the Airbus' envelope protection was active, and when the pilot called for more power, the airplane refused to give it to him. Running the engines at a higher power setting would hurt long-term service life, and the computer would not allow that.

Without more power the airplane would not climb--it couldn't--and so the airplane's belly hit the first line of trees, and "envelope protection" ended up causing the destruction of an airplane costing hundreds of millions of dollars. (Which, I add wryly, did bugger-all for the "long-term service life" of anything on the airplane.)

But no one involved could admit that envelope protection had kept the pilot from saving his otherwise doomed aircraft. Doing so would have made a lot of trouble for Airbus, and this was a brand-new aircraft which they were eager to unload on an unsuspecting world sell to airlines all over the world. If the pilot was not either incompetent or criminally neglectful it meant there was something wrong with the airplane...and there was not anything wrong with the airplane, so spoke Airbus. (And its supporting governments.) The pilot's incarceration for his "crimes" was entirely political.

The responsibility for the safe operation of any aircraft always rests with the pilot--it must. There is simply no possible way to give it to anyone else; ultimately the pilot is where the buck stops. But if this is the case, the pilot must be in full command of his airplane; the airplane itself should not get a veto.

When Airbus announced the A380 I had to wonder about the wisdom of building such an airplane. Boeing had had a number of ideas similar to it, in the 1950s and 1960s, and had abandoned them as unworkable. The 747 bears its distinctive "hump" in part because of this; but there are few airports in the world which could accommodate a bilevel airplane, and every Boeing designed after the 747 had one passenger deck rather than two.

Besides the obvious logistical issue of loading and unloading such a plane, there are issues with the weight of the thing. It's heavy; heavier even than the heaviest airplanes in service now. Most airports don't have runways which can handle that kind of mass slamming down on a routine basis.

Still, these are not insurmountable, and many were eager to see the A380 realized. But Airbus does not have a widebody jet which can compete with Boeing's 777 and 787; and the A380 is not a suitable substitute.

I suppose that I should stop concerning myself with the realities of the air transport industry. My air transport-related career ended a bit more than a month after 9/11, and now I am hardly affected at all by the competition between Boeing and Airbus. But the A380 has always struck me as a bad idea--the 21st century equivalent of the "Spruce Goose"--and events are beginning to confirm that opinion.

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