Nov. 26 (Bloomberg) -- U.S. regulators ordered airlines to avoid flying Boeing Co. 787 Dreamliners and 747-8 jumbo jets with General Electric Co. engines near thunderstorms after some of the planes experienced ice buildup.
An airworthiness directive published online today in the Federal Register instructs pilots to fly clear of high-altitude icing conditions that could sap thrust and damage GEnx engines. The Federal Aviation Administration move follows Japan Airlines Co.’s shift to other jets from 787s on some Asia routes.
The icing risk adds urgency for pilots to steer clear of thunderstorms already shunned because of potentially deadly lightning and turbulence. Jets flying at high altitudes through tropical zones can be at risk from powerful storms that promote the formation of performance-sapping ice, according to GE, the world’s largest maker of jet engines.
“It’s a relatively rare phenomenon because it requires just the right meteorological conditions,” Hans Weber, president of San Diego-based aviation consultant Tecop International Inc., said by telephone. “This isn’t a problem that will be limited to GE engines. These crystals have been found in all engines at high altitudes near thunderstorms.”
The twin-engine Dreamliner, the first jet made chiefly of composite materials, entered service with ANA Holdings Inc.’s All Nippon Airways in October 2011. Tokyo-based ANA, the biggest Dreamliner operator, uses Rolls-Royce Holdings Plc engines on its planes.
JAL’s 787s have GEnx engines, as do the Dreamliners flown by United Continental Holdings Inc., the only U.S. airline flying 787s. Chicago-based United hasn’t changed schedules or routes for its Dreamliners, said Christen David, a spokeswoman.
Atlas Air Worldwide Holdings Inc., the lone U.S. operator of 747-8s, adjusted operations after Boeing’s Nov. 23 warning for GEnx-equipped jets to stay 50 nautical miles (93 kilometers) from storms, said Bonnie Rodney, a spokeswoman.
Any disruptions for the freighters from the Purchase, New York-based company “will be minimal and can be managed with only minor reroutings,” Rodney said yesterday.
Cathay Pacific Airways Ltd., the Hong Kong-based airline, said it has 10 Boeing 747-8 freighters in its fleet that are powered by GE’s GEnx engines. As a precautionary measure, it’s standard operating procedure for 747-8 freighters to avoid flying into thunderstorms, Cathay said in an e-mailed response.
The European Aviation Safety Agency has adopted the FAA safety directive, spokesman Dominique Fouda said today.
Deutsche Lufthansa AG, the largest customer for the 747-8, said that from December the nine jets already delivered will not operate above 30,000 feet or avoid storms. Weather conditions en-route will be closely reviewed and, in some cases, other aircraft such as 747-400s equipped with other engines will be used, Lufthansa said by e-mail.
“This looks a lot like a classic teething issue,” Richard Aboulafia, an aerospace analyst at Fairfax, Virginia-based consultant Teal Group, said by e-mail. “It’s probably isolated to just the engine, and even then just one of the two engines available as options. It’s also probably easily fixed with a software tweak, rather than any kind of hardware modification.”
GE said it’s making software modifications to eliminate the ice-buildup risk and expects them to be available in the first quarter. Marc Birtel, a spokesman for Chicago-based Boeing, said the engines’ design and maintenance practices, together with the new instructions, allow for the jets’ “continued safe operation.”
“The FAA has been working closely with Boeing and GE to monitor and understand these events as the companies develop a permanent solution,” the FAA said in a statement.
Both the 787 and 747-8 have had bumpy debuts. The 747-8 was two years late in starting service in 2011, and slack demand forced Boeing to cut output. The Dreamliner, whose 2011 entry was 3 1/2 years late, was grounded for three months in January after meltdowns in the lithium-ion battery packs on two planes.
There have been six cases since April of planes with GEnx engines temporarily losing thrust in high-altitude icing conditions, Fairfield, Connecticut-based GE said Nov. 23. Five were with 747-8s and one was with a 787, according to the e-mailed statement.
Japan Air will replace 787 Dreamliners on flights between Tokyo and Delhi with Boeing 777s until Nov. 30, and will switch to 767s on its Tokyo-Singapore route, according to a Nov. 23 statement. The Tokyo-based carrier will make a decision this week on flights past Dec. 1, said Jian Yang, a spokesman.
Boeing surpassed 1,000 orders for the Dreamliner with its haul at the Dubai Air Show this month. The company handed over 57 of the four-engine 747-8s, through the end of last month, most of which are freighters.
“Airlines wouldn’t be too concerned about engines in terms of costs,” K. Ajith, a Singapore-based analyst at UOB Kay Hian Pte. “There will be some sort of compensation for airlines. Despite the problems, the aircraft is quite popular.”