Photo - Boeing
The regulatory agency of the US civil aviation, ordered an urgent correction in engines from General Electric GEnx -1B PIP2 that equip the Boeing 787 Dreamliner. The main reason would be a case occurred on January 29 this year, which was icing on the GEnx engine at an altitude of 20,000 feet while the aircraft of Japan Airlines flew from Vancouver, Canada to Tokyo, Japan. occasion occurred about 140Km of final destination and required that the number 2 engine was shut down.
According to the FAA, the civil aviation regulatory body in the US, the main cause of the problem that can lead an engine to be shut down permanently in flight is the formation of ice on the blades of the front fan, which would lead to a fan imbalance and the possibility of the tips of blades scraping the internal motor housing. This results in the recording of extensive damage inside and inability to restart the engine after being turned off in an attempt to stop the vibrations by friction of the blades with the housing.
There are 176 aircraft operated by 29 airlines around the world that may be susceptible to this problem, according to the FAA, but most of the aviation regulatory bodies follows the guidelines of the American Agency. It was decided that Boeing should perform an update in the manual of the 787 Dreamliner, which will take effect from 09 May to include ice removal procedures. For airlines recommended was to install an earlier version of the GEnx-1B, called PIP 1, which does not have the problem of friction of the blades, or perform the final repair offered by GE for PIP 2 version.
Another recommendation that will be directed to the pilots is to avoid flying above 12,500 feet in the vicinity of thunderclouds or areas with high concentration of moisture to prevent ice formation on affected by these problems aircraft.
Since GE will provide a definitive solution to the problem of MIP version 2, which consists of removal of the material in the blades of the front fan, thereby creating a greater gap between the fairing and the fan, minimizing the possibility of occurrence of friction between the parts. The deadline for completing the definitive repair is 16 consecutive hours and does not require the complete removal of the engine. By the time the final repair GE has been conducted in 40 engines.
Traditional airlines in the US said that so far reported no critical formation of ice in its GE engines fitted to the 787 Dreamliner. The American airline with largest fleet of this type of aircraft is United, with 28 Boeing 787 Dreamliner in the fleet, and then American Airlines with 15 aircraft of this type in its fleet.
In 2013, the FAA ordered airlines to avoid flying with aircraft 787 and 747-8 with GE engines, near thunderstorms. Even in sub-zero temperatures, the humidity of the storms could enter the engine and cause a dangerous formation of ice, the FAA said. The GEnx-1B engine has logged more than 3 million hours in over 250 aircraft since it came into service.
There are no reports of other problems with the GEnx engine that equips the Boeing 747-8.
