More problems with Boeing 787 and 748's
Boeing has warned airlines to avoid flying some Dreamliner planes near high-level thunderstorms due to a risk of engine icing problems.
The warning applies to 15 carriers who have 747-8 and 787 Dreamliners with engines made by General Electric (GE).
It is the latest alert for an aircraft which has suffered a number of technical glitches since its launch, including overheating lithium-ion battery systems that caused the planes to be grounded worldwide for three months earlier this year.
The engine warning follows six incidents between April and November involving five 747-8s and one 787, all of which suffered temporary loss of thrust while flying at high altitude.
The problem was caused by a build-up of ice crystals, initially just behind the front fan, which ran through the engine, a GE spokesman said.
All of the aircraft landed at their planned destinations safely, he added.
Boeing has prohibited the affected aircraft from flying at high attitude within 50 nautical miles of thunderstorms that may contain ice crystals.
In response, Japan Airlines (JAL) pulled 787 Dreamliners from two international routes.
Other affected airlines include Lufthansa, United Airlines, an arm of United Continental Holdings and Cathay Pacific Airlines.
A spokesman for Boeing said: "Boeing and JAL share a commitment to the safety of passengers and crews on board our airplanes. We respect JAL's decision to suspend some 787 service on specific routes."
JAL said it will replace Dreamliners on its Tokyo-Delhi and Tokyo-Singapore flights with other types of aircraft.
It also dropped plans to introduce 787s to its Tokyo-Sydney route from December.
The company will continue to fly the aircraft on other international and domestic routes, which are unlikely to be affected by cumulonimbus clouds for the time being.
A spokesman for GE, which is working with Boeing on software modifications to the engine control system in a bid to eliminate the problems, said: "The aviation industry is experiencing a growing number of ice-crystal icing encounters in recent years as the population of large commercial airliners has grown, particularly in tropical regions of the world."
All 747-8s are powered by GE's GEnx engines, while 787s are powered either by GE units or the rival Trent 1000 made by Rolls-Royce.
Taken from Sky News website.