United Continental Holdings Inc. said it’s almost finished with computer checkups on 96 of its Boeing Co. 757-model jets after canceling 15 flights while performing the unscheduled maintenance yesterday.
Any disruptions today will be “very minimal,” Megan McCarthy, a spokeswoman, said in a telephone interview. The “majority” of the tests on air data computers had been completed by mid-morning New York time, she said.
Some flights were delayed yesterday in addition to those scrubbed while mechanics worked on the computers, which handle data such as air pressure and temperature, McCarthy said.
The computers on the twin-engine, single-aisle 757s recently underwent upgrades in which some steps needed to return the units to service weren’t completed or were performed out of sequence, she said yesterday.
All the computers involved in the checkups have been working normally, McCarthy said. The Chicago-based parent of United and Continental airlines identified the issue at midday yesterday and began the tests immediately, she said.
Continental’s Boeing 757s aren’t affected. United and Continental merged in October, forming the world’s largest airline.
“This was voluntary by United” and not a mandatory grounding, Laura Brown, a Federal Aviation Administration spokeswoman, said yesterday in an interview.
The issue stems from an airworthiness directive from 2004 that required the installation of new circuit breakers and related components in air data computers on the 757, which U.S. carriers fly on domestic and international routes. Chicago-based Boeing ended 23 years of production of the model in 2005.
United rose 29 cents, or 1.1 percent, to $27.48 at 4 p.m. in New York Stock Exchange composite trading.