A communication breakdown between pilots and air-traffic controllers has emerged as an early focus of the investigation into last weekend’s crash of a 1990s-era Boeing 737 in Indonesia, according to people with knowledge of the probe.
The cockpit crew of the Sriwijaya Air jet, which plunged into the Java Sea minutes after takeoff, failed to acknowledge or respond to two radio transmissions from controllers questioning why the aircraft had shifted from its designated route during its climb away from Jakarta’s Soekarno-Hatta International Airport, the people said. Instead of flying northeast as expected, the plane veered northwest and at one point, a controller instructed the pilots to execute a turn to get back on track, one of these people said.
It is too early to draw definitive conclusions about the sequence of events before the crash that killed all 62 people on board, according to these people and safety experts not connected with the investigation. Indonesian authorities said the aircraft’s flight-data recorder, one of its so-called black boxes, was recovered by divers Tuesday and taken to a laboratory so its contents can be downloaded.
Authorities said they believe the location of the cockpit-voice recorder—which is the other black box—also has been identified, but rough seas prevented retrieval Wednesday.
For now, according to the safety experts, the crew’s lack of response on the radio could indicate pilot confusion or distraction. One possibility is that a problem with some mechanical or flight-control system could have consumed the pilots’ attention, they said.