* Questions about air tower closures
* Further study on use of electronics at takeoff
By Andrea Shalal-Esa
WASHINGTON, April 16 (Reuters) - The top U.S. aviation regulator said on Tuesday he expects to decide "very soon" whether to approve Boeing Co's redesigned 787 Dreamliner battery system, potentially ending a three-month ban on flights by the high-tech jet.
Federal Aviation Administration chief Michael Huerta, testifying to a congressional committee on air safety, said the agency is reviewing tests and analysis submitted by Boeing and will approve it when "we are satisfied Boeing has shown the redesigned battery system meets FAA requirements."
Huerta told reporters after the hearing that he expects the battery decision to be made "very soon."
Huerta said the FAA was working closely with the National Transportation Safety Board, which is investigating battery problems on two separate 787s in January, but would not necessarily link its decision to an NTSB hearing next week.
"We're on our own timetable in terms of completing the analysis," Huerta told reporters. "Once we're ready to move and make a determination, we will."
He also told the committee the FAA was considering separately whether to certify Boeing's 787 for extended-range operations, known as ETOPS. The plane was approved for flights over remote areas of up to 180 minutes when it was grounded for two battery meltdowns in January.
Before the grounding, Boeing had requested an upgrade to 330 minutes, but Huerta told reporters the agency was "not considering any expansion beyond that (180) at this time."
Separately on Tuesday, Transportation Secretary Ray LaHood also acknowledged a decision on Boeing is expected soon. LaHood was speaking at a dinner hosted by the Arab American Institute.
In a wide-ranging hearing, senators raised concern about Huerta's decision to close 149 air traffic control towers without providing an assessment of the safety risk as committee members requested. The closures of smaller towers would leave pilots to sequence landings themselves via radio, without an air-traffic controller.
Huerta also warned the senators that air travelers should expect "significant delays" from air traffic control furloughs that are due to start April 21. He said the reductions in air service would affect commercial, corporate and general aviation travelers. But the agency will try to minimize the harm and "buy back" furlough days for workers in coming months, to help keep towers staffed.
"We hope to buy back more of the furlough days as we're able to. This is a not a one-shot deal. We're managing this on a weekly basis."
Air traffic control experts have said the furloughs, prompted by sequestration-related budget cuts, would reduce staffing at FAA-run air control facilities by about 10 percent. That could prompt some busy airports to close runways and could lead to delays in flights. Furloughs also are expected to affect customs clearance and security screening at airports, leading to long lines for those services.
At the hearing before the Senate Commerce, Science and Transportation committee, Senator Claire McCaskill argued vehemently for dropping the ban on use of personal electronic devices during takeoff and landing, arguing that similar rules were not observed on general aviation flights. General aviation covers all non-scheduled civil air services.
She said a print copy of Tolstoy's "War and Peace" arguably posed more of a danger to a passenger than a Kindle version. Committee Chairman Senator Jay Rockefeller and other senators on the committee backed the request for more information on the issue from the FAA.
McCaskill asked Huerta to find out if passengers on Air Force One shut off electronics during take-off and landing. "Because if it's safe enough for the president of the United States, it's safe enough for the flying public," she said.
Huerta said he had asked the FAA's rulemaking committee to look into the issue, noting that personal electronic devices had evolved since the ban was first implemented. He said the committee could make some initial recommendations by July.
But he stressed that the Federal Communications Commission had jurisdiction over cell phone use on airliners, not the FAA.
NTSB Chairman Deborah Hersman said her agency had never investigated an accident in which a passenger's personal electronic device had interfered with an airplane's communications systems.