By Christopher Elliott
The New York Times
April 25, 2006

The airlines have come up with a new answer to an old question: How many passengers can be squeezed into economy class?

A lot more, it turns out, especially if an idea still in the early stage should catch on: standing-room-only "seats."

Airbus has been quietly pitching the standing-room-only option to Asian carriers, though none have agreed to it yet. Passengers in the standing section would be propped against a padded backboard, held in place with a harness, according to experts who have seen a proposal.

But even short of that option, carriers have been slipping another row or two of seats into coach by exploiting stronger, lighter materials developed by seat manufacturers that allow for slimmer seatbacks. The thinner seats theoretically could be used to give passengers more legroom but, in practice, the airlines have been keeping the amount of space between rows the same, to accommodate additional rows.

The result is an additional 6 seats on a typical Boeing 737, for a total of 156, and as many as 12 new seats on a Boeing 757, for a total of 200.

That such things are even being considered is a result of several factors. High fuel costs, for example, are making it difficult for carriers to turn a profit. The new seat technology alone, when used to add more places for passengers, can add millions in additional annual revenue. The new designs also reduce a seat's weight by up to 15 pounds, helping to hold down fuel consumption. A typical seat in economy class now weighs 74 to 82 pounds.

"There is clearly pressure on carriers to make the total passenger count as efficient as possible," said Howard Guy, a director for Design Q, a seating design consultant in England. "After all, the fewer seats that are put on board, the more expensive the seat price becomes. It's basic math."

Even as the airlines are slimming the seatbacks in coach, they are installing seats as thick and heavy as ever in first and business class — and going to great lengths to promote them. That is because each passenger in such a seat can generate several times the revenue of a coach traveler.

At the front of the cabin, the emphasis is on comfort and amenities like sophisticated entertainment systems. Some of the new seats even feature in-seat electronic massagers. And, of course, the airlines have installed lie-flat seats for their premium passengers on international routes.

Seating specialists say that all the publicity airlines devote to their premium seats diverts attention from what is happening in the back of the plane. In the main cabin, they say, manufacturers are under intense pressure to create more efficient seats.

"We make the seats thinner," said Alexander Pozzi, the director for research and development at Weber Aircraft, a seat manufacturer in Gainesville, Tex. "The airlines keep pitching them closer and closer together. We just try to make them as comfortable as we can."

There is one bit of good news in the thinner seats for coach class: They offer slightly more room between the armrests because the electronics are being moved to the seatbacks.

One of the first to use the thinner seats in coach was American Airlines, which refitted its economy-class section seven years ago with an early version made by the German manufacturer Recaro.

"Those seats were indeed thinner than the ones they replaced, allowing more knee and legroom," Tim Smith, a spokesman for American, said. American actually removed two rows in coach, adding about two inches of legroom, when it installed the new seats. It promoted the change with a campaign called "More Room Throughout Coach."

But two years later, to cut costs, American slid the seats closer together and ended its "More Room" program without fanfare. When the changes were completed last year, American said its "density modification program" had added five more seats to the economy-class section of its MD-80 narrow-body aircraft and brought the total seat count to 120 in the back of the plane. A document on an internal American Airlines Web site, which was briefly accessible to the public last week, estimated that the program would generate an additional $60 million a year for its MD-80 fleet.

United Airlines has also used the earlier-generation thin seats. But it held open the possibility that once its current seat stock needs to be replaced, it might try to squeeze in more seats. "We're always looking at options," Brandon Borrman, a spokesman, said.

Airlines can only do so much with their existing fleets to save space. The real opportunities, say seat manufacturers and design experts, are with the new generation of aircraft that are coming soon.

"People hear about these new planes, and they have bowling alleys and barber shops," Michael B. Baughan, the president and chief operating officer of B/E Aerospace, a manufacturer of aircraft cabin interiors in Wellington, Fla., said with a bit of exaggeration. "But that's not how planes are delivered. On a real airline, with real routes, you have to be economically viable."

Perhaps the most extraordinary example of a new jet that could accommodate features unheard of previously is the Airbus A380. There is so much available room on the superjumbo that Virgin Atlantic Airways is even considering placing a beauty salon in its premium-class section. (No final decision has been made, according to the company.) The first A380 is scheduled to be delivered later this year.

With a typical configuration, the A380 will accommodate about 500 passengers. But with standing-room-only seats, the same plane could conceivably fit in 853 passengers, the maximum it would be permitted to carry.

"To call it a seat would be misleading," said Volker Mellert, a physics professor at Oldenburg University in Germany, who has done research on airline seat comfort and has seen the design. If such a configuration were ever installed on an aircraft, he said, it would only be used on short-haul flights like an island-hopping route in Japan.

While an Airbus spokeswoman, Mary Anne Greczyn, played down the idea that Airbus was trying to sell an aircraft that accommodated 853 passengers, the company would not specifically comment on the upright-seating proposal.

There is no legal barrier to installing standing-room seats on an American airliner. The Federal Aviation Administration does not mandate that a passenger be in a sitting position for takeoffs and landings; only that the passenger be secured. Seating must comply only with the agency's rules on the width of aisles and the ability to evacuate quickly in an emergency.

The Air Transport Association, the trade association for the airline industry in the United States, does not have any seat-comfort standards. Nor does it issue any recommendations to its members regarding seating configurations.

The two Asian airlines seen as the most likely to buy a large plane for short-haul flights, All Nippon Airways and Japan Airlines, are lukewarm about the Airbus plan.

"Airbus had talked with us about an 800-seat configuration for domestic flights," said Rob Henderson, a spokesman for All Nippon Airways. "It does not fit with our present plans going forward."

A spokesman for Japan Airlines, Geoffrey Tudor, said Airbus had presented its ideas for using the A380 on short-haul flights, but added, "We have no interest in increasing seat capacity to this level."

Boeing is under similar pressure to squeeze more seats onto its newest aircraft, the midsize Boeing 787. Some airlines are planning to space the seats just 30 inches apart from front to back, or about one inch less than the current average.

And rather than installing eight seats across the two aisles, which would afford passengers additional elbow room, more than half of Boeing's airline customers have opted for a nine-abreast configuration in the main cabin, said Blake Emery, a marketing director at Boeing. Even so, he said, "It will still be as comfortable as any economy-class section today."

Indeed, it is possible to have it both ways: more comfortable seats that are also more compact. For example, the latest economy-class seat from B/E Aerospace, called the ICON, allows the seat bottom to move forward when the seat is reclined, so that it does not steal legroom from the passenger behind it. It also incorporates better ergonomic designs now typically found in the business-class cabin.

But the ICON and similar seats can cost up to three times more than the $1,200 that a standard coach seat costs. That may make them unaffordable to all but a few international airlines that would use the seats on long-haul routes, the experts said.

Some frequent fliers, asked about the slimmer seats, said they feared that the result would be tighter quarters. Some expressed concerns about sharing a cabin with even more passengers and increasing the risk of contracting a communicable disease.

Others were worried about even more passengers sharing the already-tight overhead bin space.

"It seems like every year there is less room for my long legs," said Bud Johnson, who is a frequent traveler for a military contractor in Scottsdale, Ariz. "I'm afraid that's going to continue."