September 15, 2002
WASHINGTON -- Airlines in the United States and abroad were inspecting new Boeing 737s Saturday to detect and remove potentially defective flight control equipment that could fail and make the planes handle like a car with bad power steering.
The Federal Aviation Administration's emergency order, which covers 737s in the 737-600 through 900 series that were produced since May 21, gives airlines 10 days to complete the review. Most of the 93 aircraft are in service, but some might be at Boeing, FAA spokesman Paul Takemoto said.
Each plane has two modules that control hydraulic fluid to the flight control system. A failure of both modules could significantly affect a plane's flight control systems by nearly jamming the controls, making the jetliner sluggish and difficult to operate, Takemoto said.
"Basically you can fly with one failed module," Boeing spokeswoman Liz Verdier said. With two out, "they feel heavier." She compared it to power steering problems on an automobile.
Verdier said the company detected the problem this month in production ground and flight tests and alerted the FAA and customers.
She would not say which airlines have taken delivery of the planes but said the company had sent notices to all its customers.
Takemoto said the FAA's airworthiness order requires carriers to check the serial numbers before flying again and replace modules with the suspect serial numbers. The FAA has no jurisdiction over foreign carriers, but they generally follow its recommendations.
To check the modules, "You just have to look up into the wheel well and check the serial number," Takemoto said.
The FAA said it's looking for a recent batch of modules with a high rate of failure. Fifteen modules were found to be defective, four in flight and 11 during ground inspections, Takemoto said. None caused an accident, he said.
Not all planes produced since May 21 have failed modules, Verdier said. "They have suspect modules," she said.
There are 84 foreign aircraft with modules from the bad batch and nine U.S. carriers, Takemoto said, but not all have been delivered. He said some of those delivered might not be in service.
Three foreign airlines reported Saturday they had acted on Boeing's warnings. Australia's two main carriers, Qantas and Virgin Blue, said they had grounded eight Boeing 737-800s to exchange the parts. At least seven flights were canceled. In Ireland, the budget carrier Ryanair grounded two 737s overnight for the repairs and returned them to the fleet Saturday.
The company that made the modules, European-based Smiths Aerospace, had no immediate comment.
James McKenna, managing editor of Aviation Maintenance magazine, said the airplanes are probably built so that if all of the flight control modules break, the pilot still has some mechanical control of the airplane.
"Still," he said, "there's a possibility that this could lead to a crash."