(Adds more from hearing, background, no Boeing comment)
By David Shepardson
WASHINGTON, May 12 (Reuters) - The head of the Federal Aviation Administration (FAA) told a U.S. House panel that an electrical issue that grounded about 100 Boeing 737 MAX planes last month worldwide appeared to be a "pretty straightforward fix."
FAA Administrator Steve Dickson told the U.S. House Appropriations subcommittee overseeing transportation that he was fully confident in the safety of the MAX that returned to service after being grounded for 20 months following two fatal crashes in five months.
"It is performing as well or better overall than any other airplane out there in the aviation system right now," Dickson said.
The FAA has daily meetings with Boeing to discuss the MAX's performance, Dickson said. In February, the FAA said it was tracking all Boeing 737 MAX airplanes using satellite data under an agreement with air traffic surveillance firm Aireon LLC.
Reuters reported on May 4 that the FAA asked Boeing to supply fresh analysis showing numerous 737 MAX subsystems would not be affected by electrical grounding issues first flagged in three areas of the jet in April.
Boeing declined to answer Wednesday when it might submit service bulletins to airlines allowing them to make fixes.
The electrical problems have suspended nearly a quarter of its 737 MAX fleet. Dickson said the FAA "is looking at both the root cause of how that change was introduced into the manfacturing process and making sure we run down whether there were any other implications."
Airlines pulled dozens of 737 MAX jets from service in early April after Boeing warned of a production-related electrical grounding problem in a backup power control unit situated in the cockpit on some recently built airplanes.
The problem, which also halted delivery of new planes, was then found in two other places on the flight deck, including the storage rack where the affected control unit is kept and the instrument panel facing the pilots.
The FAA said the issue impacts 109 in-service planes worldwide. (Reporting by David Shepardson;Editing by Elaine Hardcastle)