United retests equipment on seven Boeing 747s

LOS ANGELES (Reuters) - UAL Corp.'s (UAUA.O: Quote, Profile, Research) United Airlines said on Thursday that it is retesting the altitude indicators on seven of its Boeing 747 jumbo jets after determining that test equipment at a maintenance facility in South Korea needed to be checked for calibration.

"We have voluntarily disclosed to the FAA (Federal Aviation Administration) that we are retesting the seven aircraft today and have found no issues," United said in a statement.

One of the jets is back in service and the remainder are expected to resume normal flight operations later tonight or tomorrow, said spokeswoman Jean Medina.

United said the testing was not related to the FAA's recent air worthiness directive.

The FAA earlier this week launched an audit of maintenance records at all domestic airlines following alleged inspection lapses at Southwest Airlines Co (LUV.N: Quote, Profile, Research) that led the agency to propose a record fine of $10.2 million on March 6.

Southwest allegedly missed deadlines to inspect 46 Boeing 737s for structural flaws in 2006-07 and flew those planes after alerting the FAA about the oversight but before it completed the checks. Small fuselage cracks were found on six planes and fixed.

Southwest subsequently launched an internal review of its records and found another lapsed inspection for fuselage cracks. It immediately grounded 38 planes last week. Four were found to have cracks, the airline said.

The Teamsters Union said in a statement that United's actions highlight the risk in relying on offshore facilities for airline repairs and maintenance.

(Reporting by Deena Beasley; Editing by Christian Wiessner)