A Jetstar Airways Airbus A321-200N, registration VH-OFS performing flight JQ-987 from Perth,WA to Sydney,NS (Australia), was on approach to Sydney's runway 34L descending through about 3500 feet when the autopilot disengaged and the aircraft began an uncommanded climb. The flight crew re-engaged the autopilot and continued the approach for a safe landing about 6 minutes later.
The ATSB opened an investigation into the occurrence.
The aircraft returned to service about 33 hours after landing.
On Aug 21st 2026 the ATSB added, that after the autopilot #2 disengaged the aircraft climbed by about 400 feet reaching 3500fpm climb rate. The captain engaged autopilot #1 and continued the approach. The occurrence was rated a serious incident.
On Sep 22nd 2026 the ATSB added that they discontinued the investigation:
As the aircraft approached Sydney, it descended in dark night conditions with autopilot 2 and autothrust engaged. During the descent, westerly winds between 4050 kt were recorded by the aircrafts digital flight data recorder and the flight crew described turbulence experienced during the descent as moderate.1 At 2214 local time, air traffic control provided clearance for the crew to descend to 3,000 ft above mean sea level (AMSL) and make a left turn to join an approach for runway 34 left.
While in the turn and descending below 3,640 ft AMSL, the first officer, acting as pilot flying, asked the captain, acting as pilot monitoring, to select flaps 1. At about the same time that the captain selected flaps 1, the flight crew felt a larger turbulence encounter, the aircrafts flight envelope angle of attack protection activated, and the autopilot disconnected. The aircraft pitch also increased from 7.7° nose-up to a maximum of 17.1° nose-up and the aircraft began to climb. The autothrust system remained engaged and increased engine thrust to maintain airspeed.
As the aircraft climbed, the first officer attempted to reengage the autopilot, but turbulence once again caused the angle of attack protection to activate, and the autopilot disengaged again after 1 second. At the same time, the captain took control and manually lowered the nose to reduce the pitch angle and the angle of attack protection deactivated. The aircraft reached a maximum recorded altitude of 4,110 ft AMSL.
After reducing the pitch angle and reestablishing the descent, the captain then engaged autopilot 1. The autopilot engaged and the aircraft returned to the desired descent profile. The descent continued and the aircraft landed on runway 36 left at 2223 without further incident.
...
The ATSB strives to use its limited resources for maximum safety benefit and noted that in this case, the aircraft flight envelope protections worked as designed and the flight crew responded promptly and appropriately to reestablish the descent profile. Therefore, the ATSB considered it was unlikely that further investigation would identify any systemic safety issues or important safety lessons. Consequently, the ATSB has discontinued this investigation.
The ATSB opened an investigation into the occurrence.
The aircraft returned to service about 33 hours after landing.
On Aug 21st 2026 the ATSB added, that after the autopilot #2 disengaged the aircraft climbed by about 400 feet reaching 3500fpm climb rate. The captain engaged autopilot #1 and continued the approach. The occurrence was rated a serious incident.
On Sep 22nd 2026 the ATSB added that they discontinued the investigation:
As the aircraft approached Sydney, it descended in dark night conditions with autopilot 2 and autothrust engaged. During the descent, westerly winds between 4050 kt were recorded by the aircrafts digital flight data recorder and the flight crew described turbulence experienced during the descent as moderate.1 At 2214 local time, air traffic control provided clearance for the crew to descend to 3,000 ft above mean sea level (AMSL) and make a left turn to join an approach for runway 34 left.
While in the turn and descending below 3,640 ft AMSL, the first officer, acting as pilot flying, asked the captain, acting as pilot monitoring, to select flaps 1. At about the same time that the captain selected flaps 1, the flight crew felt a larger turbulence encounter, the aircrafts flight envelope angle of attack protection activated, and the autopilot disconnected. The aircraft pitch also increased from 7.7° nose-up to a maximum of 17.1° nose-up and the aircraft began to climb. The autothrust system remained engaged and increased engine thrust to maintain airspeed.
As the aircraft climbed, the first officer attempted to reengage the autopilot, but turbulence once again caused the angle of attack protection to activate, and the autopilot disengaged again after 1 second. At the same time, the captain took control and manually lowered the nose to reduce the pitch angle and the angle of attack protection deactivated. The aircraft reached a maximum recorded altitude of 4,110 ft AMSL.
After reducing the pitch angle and reestablishing the descent, the captain then engaged autopilot 1. The autopilot engaged and the aircraft returned to the desired descent profile. The descent continued and the aircraft landed on runway 36 left at 2223 without further incident.
...
The ATSB strives to use its limited resources for maximum safety benefit and noted that in this case, the aircraft flight envelope protections worked as designed and the flight crew responded promptly and appropriately to reestablish the descent profile. Therefore, the ATSB considered it was unlikely that further investigation would identify any systemic safety issues or important safety lessons. Consequently, the ATSB has discontinued this investigation.
This article is published under license. Article Source
Published Date
