An Ethiopian Airlines Boeing 737-800, registration ET-AOB performing flight ET-343 from Khartoum (Sudan) to Addis Ababa (Ethiopia), was enroute at FL370 when the pilots fell asleep. The aircraft continued past the top of descent maintaining FL370 and continued along the FMC route set up for an approach to runway 25L without descending however. Air Traffic Control(ATC) tried to contact the crew numerous times without success. After overflying runway 25L at FL370 the autopilot disconnected, the disconnect wailer woke the crew up who then manoeuvred the aircraft for a safe landing on runway 25L about 25 minutes after overflying the runway at FL370.
The aircraft remained on the ground for about 2.5 hours before departing for its next flight. The incident happened few days ago.
ADS-B data confirm the information, The Aviation Herald received, showing the aircraft maintained FL370 until after overflying the runway before the aircraft began to descend and manoeuvre for another approach.
Posting about the event on Twitter, aviation analyst Alex Macheras described the event as “deeply concerning”.
“Ethiopian Airlines Boeing 737 #ET343 was still at cruising altitude of 37,000ft by the time it reached destination Addis Ababa,” he wrote.
“Why hadn’t it started to descend for landing? Both pilots were asleep.”
Macheras blamed pilot fatigue for the incident.
“Pilot fatigue is nothing new, and continues to pose one of the most significant threats to air safety – internationally,” he added.