You can contribute by submitting additional or updated information.
| Date: | Sunday 21 March 2021 |
| Time: | 03:10 UTC |
| Type: |  Airbus A330-343 |
| Owner/operator: | SriLankan Airlines |
| Registration: | 4R-ALR |
| MSN: | 1689 |
| Year of manufacture: | 2015 |
| Engine model: | Rolls-Royce Trent 772-B60 |
| Fatalities: | Fatalities: 0 / Occupants: 16 |
| Other fatalities: | 0 |
| Aircraft damage: | None |
| Category: | Incident |
| Location: | Jakarta FIR -
 Indian Ocean
|
| Phase: | En route |
| Nature: | Passenger - Scheduled |
| Departure airport: | Colombo-Bandaranaike International Airport (CMB/VCBI) |
| Sydney-Kingsford Smith International Airport, NSW (SYD/YSSY) | |
| Investigating agency: | CAASL |
| Confidence Rating: |  Accident investigation report completed and information captured |
The aircraft was in cruise at FL390. Auto Pilot 2 and both FDs were engaged in ALT CRZ/NAV mode. Auto Thrust was in active mode and Mach was managed at M 0.81. At about 03:10 UTC, AP 2 had disconnected with the master warning sounding. The aircraft started to descend below the selected FCU altitude. A few seconds later AP 1 was engaged by the CP from the left seat. The aircraft was still in a descent. Subsequently, AP 1 also disengaged and the master warning wastriggered. Few seconds later AP 2 engaged by the F/O (PF). The aircraft lost altitude and descended approximately 1540ft at a rate of 5700ft/min on the VSI (Vertical Speed Indicator). Then AP2 was re-engaged by the cruise pilot in open climb mode and the aircraft commenced climb to FL 390.
Probable causes: The disconnection of the AP on both occasions was caused by a force applied to the F/O’s
side stick. A warning was triggered as this was not the recommended procedure to disconnect the AP. Poor situational awareness and non-adherence to SOPs in handing over and taking over of controls culminated in the AP disconnection on two occasions and which resulted in loss of altitude.
Accident investigation:
 |
|
Sources:
CAASL
History of this aircraft
Other occurrences involving this aircraft
| 27 May 2018 | 4R-ALR | SriLankan Airlines | 0 | Cochin International Airport (COK/VOCI) |  |
min |
| 28 June 2023 | 4R-ALR | SriLankan Airlines | 0 | near Colombo-Bandaranaike International Airport (CMB/VCBI) |  |
non |
| Landing gear issues | ||||||
| 19 September 2023 | 4R-ALR | SriLankan Airlines | 0 | near Colombo-Bandaranaike International Airport (CMB/VCBI) | |
non |
| Near miss | ||||||
Location
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 03-Mar-2025 10:12 | Prometheus | Added |
| 03-Mar-2025 10:13 | ASN | Updated [Source, Accident report, ] |
Corrections or additions? ... Edit this accident description
The Aviation Safety Network is an exclusive service provided by:
Quick Links:
| ASN Home | Send Correction / Feedback |
| FSF Home | Disclaimer | Copyright |
| Contact Us | Privacy Policy |
| Press / Media |
CONNECT WITH US:
©2025 Flight Safety Foundation