United cancels flights and grounds 777s for tests

By John Crawley

WASHINGTON (Reuters) - United Airlines, a unit of UAL (UAUA.O), on Wednesday grounded its entire fleet of Boeing (BA.N) 777 jetliners and cancelled flights to reexamine a fire suppression system.

United's announcement on its 52 long-haul 777s comes amid growing congressional and other scrutiny of airline maintenance and inspection practices and questions about Federal Aviation Administration oversight.

A hearing on the matter is scheduled for Thursday in the U.S. House of Representatives.

Four of United's rivals have in recent weeks taken aircraft out of service and cancelled flights for lapsed maintenance inspections.

United said in a statement on Wednesday that it discovered during a regular review of maintenance records that tests on a fire suppression system in the cargo hold had not been thorough enough.

United said it voluntarily disclosed the problem to the FAA.

"United will not operate these aircraft until the tests are complete," the company said.

United said it had cancelled 31 of its 84 daily 777 departures, which are mainly for flights to Europe and Asia. More cancellations are possible on Thursday, it said.