The Federal Aviation Administration (FAA) said on Friday it wanted the US carrier Boeing Co () 143 of the 737 Classic aircraft to investigate the potential wiring failures arising from an investigation into a plane crash. Indonesia in January
The 737 Classic is a two-decade older aircraft, the FAA said the issue affected 1,041 737-300, -400 and -500 Classic series aircraft worldwide, but many are now shut down due to the issue. COVID-19 or other problems
The FAA is issuing an airworthiness directive to let operators verify that the flap’s synchro wire, which plays a role in the aircraft’s automatic throttle system, is firmly connected to the safety sensor.
Wiring failures may not be detected by auto-throttle computers on affected aircraft and pose a safety risk.
The FAA wanted a faster review than Boeing suggested, saying late Friday. “It contributes to an ongoing effort to deliver improvements in safety and efficiency across the fleet.”
The 737 MAX and the newer 737 NGs were not affected by the order.
The FAA and Boeing have identified problems that may arise during an investigation into the Sriwijaya Air Flight 182 crash on January 9 in the Indonesian capital.
The crash of Indonesia’s third major airline in just six years highlights the Southeast Asian country’s poor air safety record.
On board, 62 people died after a 26-year-old Boeing 737-500 crashed into the Java Sea shortly after take off from Jakarta.
The FAA said there was no evidence that flap synchronization problems were involved in the accident, although the possibility of a failed connection demonstrated a safety concern that warranted timely attention.
In February, Indonesia’s National Transportation Safety Board (KNKT) said the aircraft had unbalanced engine propulsion that eventually caused the plane to land rapidly before its final dive into the sea.
There have been two previous reports of problems with the automatic throttle system that automatically controls engine power, according to maintenance records. But the problem was resolved four days before the crash, the agency said.
Boeing sent a message to operators on March 30 ordering them to conduct an electronic inspection of the automatic throttle computer to confirm that the line was connected within 250 flight hours.
The FAA requires preliminary testing within 250 flight hours or two months from now, whichever comes first. “To ensure low-rate aircraft can be corrected in a timely manner,” the operator will then make repairs if necessary.
The FAA said a faulty connection could result in the automatic throttle system failing to detect the wing position if the aircraft’s engine was operating at different thrust settings due to other faults.
The FAA requires monitoring every 2,000 hours after the first flight.
The U.S. carriers affected include Aloha Air Cargo, DHL, iAero Airways, Kalitta Charters and Northern Air Cargo, the FAA said.
(Corrects second paragraph to say that there are many out of service at the moment, few of them)
Our Standard: The Thomson Reuters Trust Principle.