United Airlines' rough merger puts passengers on a bumpy ride CHICAGO - It was an unusually bright, sunny day at Chicago O'Hare International Airport as passengers at Gate B9 of Terminal 1 waited to board a Boeing 757. The flight schedule monitor in the terminal said United Airlines Flight 629 to San Francisco would leave on time. The monitor was wrong. A gate attendant fired up the public address system. We have a new departure time. They're taking this plane away," she said, offering no further explanation. The 12:17 p.m. flight would be delayed to 1:30, she said. Passengers crammed into seating near the gate let out a collective groan. The scene has played out time and again at United Airlines terminals since United and Continental combined in a $3.2-billion deal to form the world's largest carrier, and especially since it had a trouble-plagued conversion to a new computer system March 3. United is the most complained-about airline in America by far, according to the latest statistics from U.S. Transportation Department. During March, United's on-time performance was worst among the major airlines in the U.S., according to those statistics. Among large, full-fare airlines, United rates worst in mishandled bags and denied boardings, a term for passengers who hold confirmed reservations but are bumped from a flight because it is oversold. To see what United's troubles might portend for the busy summer travel season, I took a two-day excursion from Chicago to San Francisco to Las Vegas to Houston and back to Chicago to witness firsthand the passenger experience. The trip involved about 25 hours of flying and waiting at airports, including three of United's hub airports. The trip was a microcosm of what United passengers say and what the industry statistics suggest: Flights on United Airlines nowadays can go relatively smoothly, but if there's a problem, things can go very wrong in a hurry. Much of this trip was uneventful, even pleasant, but one flight was frustrating and exhausting. I experienced good and lousy customer service along the way. Every flight was full, overhead bin space always ran out, and the only bag I checked - and paid $25 for the service - didn't show up at the baggage claim. However, on one return flight I basked in a satisfying flying experience after splurging for roomier Economy Plus seating and in-seat television service offered on a newer plane. United executives know the recent industry statistics aren't good and acknowledge that the airline is dealing with problems. "We've got to improve," said Martin Hand, United senior vice president of customer experience. The last year and a half to two years have been a challenge, no doubt about it. Executives are examining every way the customer interacts with the airline, from the first point of contact, such as searching for fares on its website and booking a ticket, through picking up luggage at baggage claim after a flight, Hand said. "I wish I could flip a switch and make it happen overnight," he said of United's efforts to fix problems. This is going to be a journey. My journey in mid-May did not start well at O'Hare. After the delay announcement at Gate B9, a line immediately formed at the gate agent counter, mostly passengers who would miss their connecting flights in San Francisco and needed to rebook on later flights. Me included. Patience in the customer help line, 15 people deep, wore thin as gate agents were slow in rebooking passengers. My waiting time in line? One hour and 26 minutes. Some people in line grew noticeably restless and irritable. Many tried, seemingly unsuccessfully, to rebook connecting flights by cellphone. When it was finally my turn, the gate agent maintained a cheery disposition but clearly was uncomfortable with the new computer system. Her demeanor soured as she fumbled, reaching next to her keyboard for two pages of computer instructions, a mix of typed and handwritten notes. Aviation consultant Robert Mann said he had heard similar stories about perplexed United agents. "It's still a case where agents are not comfortable with the new software," Mann said. It's kind of a learning curve, but you have to wonder how long this kind of thing can go on. Hand, the United executive, said it had been a challenge to retrain longtime workers on a new computer system. It's most apparent when things go wrong, such as flight delays and cancellations, something the industry calls "irregular ops." Now, more than two months after the conversion, United is conducting a second round of training to fill in gaps and help struggling employees.