The Making of United's Summer From Airline Hell

United and Continental closed their merger in 2010 and created what was then the world’s largest airline. Fifty-seven months later, executives are still working to integrate United Continental Holdings into a single company—and struggling with some high-profile operational and customer service problems.

Over the past six weeks, United suffered two technology glitches that grounded flights, including a two-hour network outage on July 8 that halted flights worldwide and was traced to a faulty router. Those incidents followed other technology mishaps in 2012 and 2014, which snarled reservations and crew-schedule systems. United upgraded the Chicago data center housing all its IT infrastructure, spokeswoman Megan McCarthy said, refuting notions that the airline has pinched pennies on technology. But there has been turnover in the carrier's top tech job: Linda Jojo became chief information officer in September, the third executive in that role since the 2010 merger.