Sriwijaya Air FDR Recovered; Concerns Over Air Check Valve
The flight data recorder (FDR) of Sriwijaya Air flight SJ182 was recovered by Indonesian naval divers on the evening of Jan. 12, three days after the Boeing 737-500 carrying 62 people plunged into the sea.
The FDR will be handed over to the Indonesian National Transportation Safety Commission (KNKT) for further investigation.
The search team has yet to recover the cockpit voice recorder (CVR) although they have determined its position through its underwater locator beacon.
KNKT added that the crew did not declare any emergency prior to the Jan. 9 crash and radio conversation with air traffic control appeared “normal and nothing suspicious.”
The 737-500, registered PK-CLC, had been put into storage on March 23, 2020 following COVID-19 related capacity cuts. According to Aviation Week Intelligence Network Fleet and Data Services, the aircraft was stored at Semarang Ahmad Yani International Airport (SRG), in Central Java, Indonesia.
According to the Indonesian transport ministry’s spokesperson, the aircraft has a Certificate of Airworthiness valid until Dec. 17, 2021. The Directorate General of Civil Aviation had inspected the aircraft on Dec. 14, 2020 prior to its return to commercial service on Dec. 22.
Sriwijaya CEO Jefferson Jauwena noted in a statement that in March 2020 the airline underwent Flight Safety Foundation’s Basic Aviation Risk Standard (BARS) safety audits and met all of the safety requirements.
On July 23, 2020, the U.S. FAA issued an emergency airworthiness directive that ordered inspections for corrosion of the engine bleed-air fifth-stage check-valve internal parts on the 737-500 that might have occurred after long-term storage.
“If this valve opens normally at takeoff power, it may become stuck in the open position during flight and fail to close when power is reduced at top of descent, resulting in an unrecoverable compressor stall and the inability to restart the engine,” the FAA said. The regulator’s directive applied to the 737-300, -400, -500, -600, -700, -800 and -900 that are either powered by the CFM56-3 or the CFM56-7.