MEC&F Expert Engineers : Boeing Co.’s newest 747 jumbo jetliner faces a risk of dangerous vibrations, known as “flutter,” in limited situations

Thursday, July 16, 2015

Boeing Co.’s newest 747 jumbo jetliner faces a risk of dangerous vibrations, known as “flutter,” in limited situations


JULY 15, 2015
 
Boeing Co.’s newest 747 jumbo jetliner faces a risk of dangerous vibrations, known as “flutter,” in limited situations, the Federal Aviation Administration said.

Data analysis shows that “divergent flutter,” oscillations of a wing that could cause it to break up, may occur on the 747-8 during a “high g-load maneuver in combination with certain system failures,” the FAA said Wednesday. G-loading refers to the stresses on a plane that can increase during acceleration and turns.

Operators of the passenger and freighter versions of the hump-backed jets are required to make wing repairs during the next year to five years to avoid safety issues, according to an FAA air worthiness directive (see  bulletin).

The required modifications apply to eight 747-8 aircraft operated in the U.S. Boeing will pick up the tab for repair costs estimated at about $400,000 per jetliner because the planes are still under warranty, the FAA said.

The directive makes mandatory changes that Chicago-based Boeing had recommended to operators in February 2014 “to ensure airplanes are configured with the latest certified software and system changes,” Karen Crabtree, a company spokeswoman, said in an e-mail.

About 71 of the four-engine jets delivered globally before that date are affected, she said