The letters were recently sent to American and United airlines' frequent fliers who were affected by problems at O'Hare International Airport, with United throwing in an extra 2,500 miles for members of its Mileage Plus Premier program, airline spokespeople said Tuesday.
"It was a proactive measure to acknowledge delays we've experienced there," United spokeswoman Susanna Leyva said.
American Airlines spokeswoman Mary Frances Fagan said similar letters have been sent several times in the past two years to "recognize difficulties that some of our frequent flier passengers may have had."
In American's letter, B.J. DeSena, vice president at O'Hare International Airport, asked passengers to "overlook our poor performance ... and give us another chance." United, meanwhile, stressed its commitment to improving service.
Leyva and Fagan said the letters were not prompted by the recent Federal Aviation Administration report showing that delays and cancellations for the first six months of this year are almost double those of a year ago. During the first five months of this year, for example, 23,141 flights were held up at O'Hare, compared with 11,464 in the same period in 1998.
Not surprisingly, the increase was accompanied by a rise in the number of passenger complaints lodged against airlines - 6,582 so far this year, compared with 3,681 last year.
Fagan and Leyva said weather and air-traffic control problems were mostly to blame for the delays. The airlines also have blamed other infrastructure deficiencies, combined with record passenger loads, for the blunders.
A passenger advocate agrees, at least in part.
"You have to include the FAA and Congress for failing to provide sufficient aviation infrastructure to deal with these loads," David Stempler of the Air Travelers Association, told the Chicago Tribune.
But many passengers say corporate greed has caused air carriers to skimp on service.
"It is about packing the tin can as much as possible," said Art Brodie, who travels more than 100,000 miles annually for his business. "You pay more and more money to get less and less," he said.
Frustration and anger by air travelers also has translated into a rise in the number of incidents of passenger misconduct - including violent attacks on airline employees. In 1998 there were about 5,000 reports of misconduct, a 26 percent increase over the year before.
"The whole experience stinks," said Bob Redmond, a pharmaceutical salesman, who says he has run out of patience. Redmond regularly shuttles between New York and Chicago.
"The airlines have no credibility. Not a shred," he said.
United Airlines is based in the Chicago suburb of Elk Grove Village, Illinois. American Airlines is based in Fort Worth, Texas.