Never has so much ink been used to write about 1-1/2% of the market.

And much more will wet the presses here at Farnborough as Boeing and Airbus vie for the lucrative top end of the airliner market, each claiming their new aircraft is better than the other.

At stake are bragging rights to the world's biggest airliner-a Boeing 747 replacement according to Airbus, and an extension to the 747 family, according to Boeing.

Airlines are watching the bunfight. Several have told Airbus the 550-passenger A3XX is just what they need-but none has put down any cash. Many have said they are extremely interested in the Boeing 747X, "but none have said they are buying," according to chief Boeing salesman Seddik Belyamani (who, ironically, graduated from university in Toulouse).

Airbus and the airlines have said the A3XX must be 15% more efficient than the current Boeing 747-400 to succeed; Airbus claims it is, while Boeing says whatever the A3XX can do, the 747X will be even better. From there, the two rivals agree about little at all except the rival airplanes will have essentially the same four engines.

Even the size of the market is an issue. Boeing sees a potential for no more than 400 aircraft over 20 years, Airbus at twice to three times that. Airbus is anxious to go ahead with the plane, which will cost $12 billion to develop; Boeing is biding its time, knowing it can wait until next year to spend $5 billion to design its derivative and still match an entry into service date of 2005.

If Boeing's analysis of the A3XX is correct, one must question why Airbus would want to go ahead with such a flawed design, and why a number of airlines have expressed interest in it. And if the Airbus claims are correct, then the A3XX is far more advanced aerodynamically and economically than Boeing engineers imagine.

The problem with comparing the rival claims is in the small-and sometimes even smaller-print. For example, do trip and seat mile costs include all costs, such as weight-based landing and navigation fees-an important consideration for the bigger A3XX, which comes in considerably heavier than the Boeing 747X?

Boeing says Airbus is better at marketing than analysis; Airbus says it cares not how Boeing assesses the A3XX, but what the airlines make of it-and they are highly experienced in evaluating Airbus designs without Boeing's help. Airbus asks who wants the old technology of the 747X; Boeing says it is quite good enough, thank you, and far less risky than the all-new A3XX.

And so the arguments will rage on here at Farnborough. Watch this space!

By John Morris