In the wake of last month’s Indonesian jetliner crash into the Java Sea which killed all 62 people on board, US airplane manufacturer Boeing has issued an updated safety bulletin.
The bulletin reminds pilots of the steps required to ensure they maintain control of their aircraft in challenging circumstances.
The Flight Operations Technical Bulletin was sent out this week, designed to “reinforce active flight crew monitoring of airplane state and flight path management to prevent airplane upsets.”
The document serves as a timely reminder for pilots to monitor their aircraft for the kind of technical issues that occurred prior to the crash and how to recover from such situations.
“Loss of Control In-flight remains the single greatest cause of fatalities in commercial aviation,” the company said in the document reviewed by Bloomberg News. “This bulletin is meant to reinforce the importance for active monitoring of the airplane state while managing the airplane flight path.”
Less than three minutes after departing from Jakarta, the left engine on the Sriwijaya Air 737-500 plane began reducing power as the right engine’s setting remained the same, according to a preliminary report issued 10 February by Indonesia’s National Transportation Safety Committee.
Such unequal thrust settings can cause a plane to turn if they aren’t countered properly.
According to the report, there were indications the pilots weren’t able to maintain their assigned heading. At the same time, the flight crew was attempting to turn around a storm, so might also have been distracted.
Flight SJ 182 crashed into the Java Sea on 9 January, four minutes after take-off from Jakarta.
Divers subsequently retrieved from the seabed the flight data recorder of the 26-year-old Boeing Co 737-500 jet.
The Sriwijaya crash was the biggest airline disaster in Indonesia since October 2018, when 189 people were killed onboard a Lion Air Boeing 737 MAX that also plunged into the Java Sea soon after take-off.
In the bulletin, the company lists various causes that can trigger a loss of control, which include malfunctions and incorrect actions by pilots. Preventing such concurrences “involves the active participation of both pilots,” it said.
“Active monitoring skills are essential to facilitate early detection of conditions that can lead to an airplane upset,” the company said. An upset occurs when a plane flies too slowly or banks, climbs or descends too steeply.
It also warned against distractions and complacency. “Highly automated and reliable flight control systems have greatly reduced pilot workloads, but the requirement for monitoring complex systems has increased,” it said.