In the race to offer lower fares, airlines have been boosting load factors -- and the discomfort of many passengers.
FORT WORTH, TEXAS - The day started poorly for Allison Quate.
Her flight from Oklahoma to Dallas-Fort Worth International Airport was severely delayed. She missed her connecting flight to Washington and spent six hours marching between terminals and gates, trying to get on another plane. They were all full.
By 5 p.m., the 23-year-old found herself standing anxiously at her fifth gate, competing with 22 other standby passengers for a seat on the American Airlines jet bound for Washington.
"This is very disappointing," she said, just before the gate agent closed the door, forcing Quate to head to another plane. She eventually landed in Washington at 1:30 a.m., 11 hours behind schedule.
"If you miss your flight, you can't catch another one because they are so full," she said. "If there is even one little problem, you just aren't going to make it."
Over the course of a year that many airline passengers would rather forget, most attention has been focused on travel woes created by record-setting flight delays. But another trend may be causing as much havoc and frustration for passengers: Planes have never been so packed, federal data show.
The jammed flights have changed the experience of flying. Passengers complain of less personal space as they get poked by others' elbows. Overhead bins fill up. Even bathroom lines stretch farther down the aisles, frustrating those with aisle seats. And for unfortunate travelers like Quate, the packed planes have upset travel plans, making it difficult for airlines to recover after disruptions and get passengers to their proper destinations.
Planes are particularly full during the holiday and summer travel seasons, when leisure travelers and business travelers compete for space. "You just feel like a sardine," said Shirley Warren, 57, stuck in a middle seat for a flight from Washington to Dallas. "It's not comfortable."
Sitting in the last row of coach class on the same flight, Alicia Mosher, 18, said the crowded plane -- it was 90 percent full -- made her feel "anxious."
"You just don't feel as relaxed," she said.
Federal data show that planes have grown steadily more packed in the past two decades. In 1990, U.S. air carriers' planes were about 62 percent full. By 2000, the figure had climbed to 71 percent. Through the first eight months of this year, planes were 81 percent full, according to the Bureau of Transportation Statistics.
Why the increase? A strong economy has spurred business and leisure travel in recent years. But airline executives and analysts point to complex forces that are also responsible for driving up "load factors," the industry's measure of how many seats get filled.
Just 10 years ago, airlines could make money on a flight that was a little over half full, because business travelers were willing to pay thousands of dollars for a ticket, compensating for unsold seats. But when the tech bubble burst in 2000, business travel and demand for expensive seats declined. The 2001 terrorist attacks also hurt leisure travel. Both trends forced many carriers to slash costs and try to find ways to fly more efficiently.
Meanwhile, such low-cost carriers as Southwest Airlines and AirTran Airways continued to grow, spurring demand for air travel from people who may not have flown much, or as much, before. That prodded traditional carriers to match cheap fares to remain competitive. Travel-booking websites such as Orbitz and Travelocity also made it easier for passengers to compare fares, further reducing ticket prices.
The lower fares meant airlines could no longer rely on a few expensive tickets to keep a flight profitable. They altered their tactics to concentrate on filling planes with more passengers on cheaper tickets to offset the loss of steeper fares.
Surging fuel prices have also encouraged airlines to carry as many passengers as possible on each plane and to better match routes with the appropriate-size aircraft. The high fuel costs made it too expensive to fly jets not loaded to the gills, leading carriers to reduce capacity, hold it steady or slow growth plans.
Airlines also upgraded their technology and ticketing systems, allowing them to book flights more efficiently.
The trend of packed planes is not likely to change anytime soon, executives said, because most airlines are not going to add planes to their fleets in the near future.
"Frankly, this is the only economic way we can continue to provide low fares," said John Tague, a vice president at United Airlines, which has reduced its domestic flights by nearly 5 percent to help boost load factors.
United's planes were 84 percent full through August, federal data show.