NEW YORK/ WASHINGTON DC: US officials have ordered Boeing to fix engines on some of its 787 Dreamliner airplanes to avoid sudden failure in icy conditions, calling the problem an "urgent safety issue."
Friday's Federal Aviation Administration directive concerns a potential problem in General Electric's most advanced engines that affects 176 planes worldwide, following a January incident that caused an engine on a Boeing's newest 787 passenger jet to fail mid-flight.
Although pilots on the Japan Airlines flight from Vancouver to Tokyo shut down the engine, the incident was not deemed serious because the plane's other engine, and older version of the same model, was not susceptible to the problem.
Boeing's most sophisticated passenger plane, the Dreamliner is constructed largely of advanced lightweight carbon-fiber reinforced composite materials that reduce fuel use.
However, a series of problems has plagued the aircraft during development and production as well as since its first commercial flight in late 2011.
The latest issue involves natural icing that occurs at lower altitudes in winter weather, Boeing spokesman Doug Adler said.
The FAA said it was ordering modifications that would prevent ice from accumulating on fan blades in GE's GEnx engines, making them rub against the engine casing, which can cause "damage and a possible in-flight non-restartable power loss of one or both engines."
At least one of the engines on all affected 787 Dreamliners must be repaired or replaced within five months.
The FAA directive concerns only the 43 planes operated by US-based airlines.
However, other countries, which typically follow the FAA's regulations, are also expected to comply.
GE first recommended the repairs earlier this month after it investigated the problem jointly with Boeing and "worked with the FAA on a plan to fully resolve it," Adler said.
More than 40 Dreamliner engines have been fixed so far, he added.
The repairs -- involving grinding down engine casings -- can be done without removing the engines from planes.
Boeing has already complied with another of the FAA directive's orders, for pilots to be alerted to new operating procedures for coping with possible icing problems, Adler said.
The engine issue is just the latest to have affected Dreamliner planes.
An All Nippon Airways 787 was forced to return to Kuala Lumpur in February after the engine overheated.
Last year, the FAA ordered repairs to correct a software bug that could have caused the aircraft to suddenly lose all power.
In 2013, the Dreamliner was grounded globally over a separate electrical problem.
Early that year, several planes experienced problems with batteries overheating that caused a fire on one aircraft. Changes were made to prevent recurrence.