WASHINGTON, Jan. 27 (UPI) -- Federal regulators are tightening their scrutiny of questionable elevator lifts on Boeing 767 jets and ordering some upgrades, an order to U.S. airlines says.
Concern about the elevators on 767 jets has been ongoing for at least a decade with Boeing issuing a series of bulletins on them, the Wall Street Journal reported Monday.
While no accidents have been blamed on elevator malfunctions, there is concern that elevators can jam, causing a pilot to lose control of the aircraft, the Journal said.
The Federal Aviation Administration's order calls for enhanced inspections of more than 400 jets. The FAA said "failures or jams in the elevator system [can cause] significant upset and possible loss of control."
The elevators are movable parts of the tail sections that control horizontal lift.
Some airlines, including United Airlines, which is now part of United Continental, had opposed the FAA's intention to order enhanced inspections, claiming Boeing's service bulletins on the matter were enough to provide for safe flying.
The problem surfaced in 2000. Since then, Boeing has issued six service bulletins and redesigned the elevator mechanisms. Some jets have already upgraded to the new design, the Journal said.
The mechanical linkages that move the elevators are called bellcranks. There are six on each aircraft. The FAA said if two or more of the bellcranks failed, a pilot could lose control of the aircraft.
The enhanced inspection order starts in March and demands questionable parts be replaced within six years, the Journal said.