A SAA South African Airways Airbus A330-300, registration ZS-SXJ performing flight SA-314 from Cape Town to Johannesburg (South Africa), was enroute at FL410 about 240nm northeast of Cape town when the aircraft experienced pitch up and down oscillations, the crew noticed the speed trend was indicating 40 knots over barber pole, disconnected the autopilot and climbed the aircraft to FL412. The aircraft subsequently descended to FL390 and continued to Johannesburg for a safe landing.
South Africa's CAA reported on Jan 8th 2025: "While en-route to WMKJ (Editorial note: Senai, Malaysia) at flight level (FL) 410, the aircraft began to oscillate between pitch-up and pitch-down movements, slowly gaining momentum. The co-pilot, who was the pilot flying (PF), immediately noticed the speed trend vector increasing to approximately 40 knots into the overspeed (red barber pole) protection area. To prevent an overspeed event, the autopilot (AP) was immediately disconnected, and the aircraft was gently pitched down to approximately 1.5 to 2 degrees (Editorial note: ?), which stopped the speed acceleration (Editorial note: ???). The speed trend vector then indicated a trend toward the vertical indicator/vertical protection (Vls/Vprot) range, as the aircraft descended (???), showing a similar 40 to 50-knot change in the speed trend vector. The PF instructed the pilot monitoring (PM) to request a descent from the Air Traffic Control Officer (ATCO) to vacate the flight level and increase the margins between the high and low-speed protections. The PM turned the seatbelt sign to ON and requested a descent to FL390. The aircraft descended to FL390 without further incident. The aircraft diverted to O R Tambo International Airport (FAOR). This oscillation, followed by the rapid approach of the speed trend vector to the overspeed and vertical indicators, occurred within just a few seconds. There was no indication of turbulence on the synoptic charts or in the Aviation Routine Weather Report (ARMS) predictions. Meanwhile, the cabin crew were conducting a breakfast service, and plastic containers from the breakfast trays slid off the passenger chair trays, causing Uood to scatter throughout the back economy section of the aircraft. Food and beverages were scattered from the trolleys too. "
According to flight plan, flight SA-314 always was scheduled to fly from Cape Town to Johannesburg. It would also be amazing to see an A330-300 at FL410 that early for such a long distance flight to Malaysia.
On Oct 21st 2025 South Africa's AIID released their final report reporting, that one crew member received serious and three minor injuries in the upset, and concluding the probable causes of the accident were:
The aircraft flew into clear air turbulence which led to the up and down oscillation of the aircraft; as a result, the cabin crew members incurred injuries as they were serving breakfast, including hot beverages, at the time.
Contributing Factor
- The PF disregarded the Airbus Pilots Operating Handbook (POH) and disengaged the autopilot without proper communication to the PM at the time of the incident.
- The aircraft weather radar did not show any significant weather in the vicinity.
- Poor Crew Resource Management
The AAID analysed:
The flight departed from Cape Town International Airport (FACT) in Western Cape province and was scheduled to stop at O.R. Tambo International Airport (FAOR) in Gauteng province.
The aircraft took off at 0620Z and climbed to FL 410. The autopilot (AP) was engaged during the climb phase and cruise phase at FL 410. The cabin crew members had started serving breakfast at the time the serious incident occurred and the seat belt sign was OFF. The cabin crew always advises passengers to keep their seat belts on even if the sign is OFF.
According to the aircrafts data report at 06:53:09Z, the aircraft was cruising at 243.3 kts (Mach 0.816) and the vertical speed was 0. At 06:53:21Z, the aircraft encountered clear air turbulence (CAT); as a result, the speed trend arrow suddenly increased and the aircraft started to gain momentum slowly. The increase and decrease occurred a few times which prompted the FO to disengage the AP at 06:53:29Z and, thereafter, she informed the captain to request a descent to FL 390 whilst she (PF) was manually engaged in recovering the aircraft from the turbulence. The aircraft recorded a maximum airspeed of 258 kts (Mach 0.860) and a vertical speed of -2176 ft/min. During this period, the aircrafts level fluctuated from 41176 ft to 40404 ft. The AP was engaged again at 06:54:13Z. The height fluctuations continued until the aircraft descended to FL 390 at 06:55:29Z.
As the cabin crew members were serving breakfast at the time of the serious incident, they suffered most injuries because they were standing. Moreover, there was no turbulence warning issued. The crew members who were in the aft galley were thrown around the cabin with food spilling off from the trolleys. Some of the injuries involved burns caused by hot beverages. Even though the passengers were startled and some screamed, none of the passengers was injured. The seat belt sign was switched to ON before the descent to FL390.
According to the official weather report, jet streams were predicted in the vicinity of the flight.
Jet streams are preferred by pilots as they save time and fuel. The report also noted that at certain areas close to the serious incident area, the upper winds were greater than 60 kts.
The winds also decreased from 100 kts at FL 360 to 80 kts at FL 410. The weather radar which was set to weather, turbulence and hazard mode (WX+T+HZD) within 40 nm in the aircraft did not show any clouds even though at lower levels there were broken clouds at a base of 3000 ft; hence, they were not aware of the turbulent condition. As a result, the cockpit crew did not alert the cabin crew about the turbulence or change the seat belt sign to ON.
The Airbus report indicated that there was a load overspeed during the turbulence but did not exceed the manufacturer limits:
- Max Calibrated Air Speed (CAS): 262 kts vs Maximum operating speed (VMO) = 330 kts.
- Max (Mach number) Mn: 0.875 vs (Maximum Mach Operating) MMO = 0.86. (ΔMn =
0.015) and duration (9s).
- Time Over Limit (TOL): 9s
- Load factors variations (during the overspeed window): 0.738G to 1.588G
This load report confirmed an overspeed (MMO) event of limited amplitude (ΔMn = 0.015) and duration (9s).
When the aircraft encountered turbulent conditions, the trend vector initial indication was towards overspeed and that is when the aircraft pitched down and, a few seconds later, pitched up, changing the trend towards Vls. The FO thought the aircraft would stall; it seemed as though the FO did not immediately recognise that they had flew into clear air turbulence (CAT). During the interview, the FO insisted that the aircraft was porpoising like riding a wave, and not in turbulence. Without confirming with the captain, the FO disengaged the AP and tried to settle the aircraft on her own, which resulted in her chasing the aircraft (chasing the aircraft means that the pilots reaction is not matching the aircrafts movement). In the Airbus report, there were four instances where the angle-of-attack was triggered and, at those times, the PFs side stick was in the nose-down direction. The report also indicated that the aircraft experienced a 0 G-load factor during that period which was likely the period when some of the cabin crew members were injured.
The captain indicated that he was unable to see the FOs input as the side stick was on his right-hand side. The FO did not follow the Airbus Flight Crew Technique Manual (FCTM) Overspeed Prevention Technique which recommends keeping the AP engaged and deploying appropriate speed brakes level if an overspeed condition is impending. The aircraft exceeded MMO for 9 seconds and triggered an overspeed warning which lasted 4 seconds but the FO said she did not hear any warnings. The captain confirmed that they received the warnings; however, due to protocol, he did not see the need to intervene since the situation was still contained. The captain may have not intervened since the FO was more experienced on the aircraft type and he may have been complacent when he assumed the PF would complete the actions required in line with the AFM. This was evident in his statement He indicated that when the turbulence started and the trend vector was pointing towards overspeed, he assumed the FO would deploy speed brakes to arrest the situation.
The simulation conducted by Airbus demonstrated that the aircraft recovers faster and the turbulence fluctuations are less when speed brakes are deployed and AP is engaged.
South Africa's CAA reported on Jan 8th 2025: "While en-route to WMKJ (Editorial note: Senai, Malaysia) at flight level (FL) 410, the aircraft began to oscillate between pitch-up and pitch-down movements, slowly gaining momentum. The co-pilot, who was the pilot flying (PF), immediately noticed the speed trend vector increasing to approximately 40 knots into the overspeed (red barber pole) protection area. To prevent an overspeed event, the autopilot (AP) was immediately disconnected, and the aircraft was gently pitched down to approximately 1.5 to 2 degrees (Editorial note: ?), which stopped the speed acceleration (Editorial note: ???). The speed trend vector then indicated a trend toward the vertical indicator/vertical protection (Vls/Vprot) range, as the aircraft descended (???), showing a similar 40 to 50-knot change in the speed trend vector. The PF instructed the pilot monitoring (PM) to request a descent from the Air Traffic Control Officer (ATCO) to vacate the flight level and increase the margins between the high and low-speed protections. The PM turned the seatbelt sign to ON and requested a descent to FL390. The aircraft descended to FL390 without further incident. The aircraft diverted to O R Tambo International Airport (FAOR). This oscillation, followed by the rapid approach of the speed trend vector to the overspeed and vertical indicators, occurred within just a few seconds. There was no indication of turbulence on the synoptic charts or in the Aviation Routine Weather Report (ARMS) predictions. Meanwhile, the cabin crew were conducting a breakfast service, and plastic containers from the breakfast trays slid off the passenger chair trays, causing Uood to scatter throughout the back economy section of the aircraft. Food and beverages were scattered from the trolleys too. "
According to flight plan, flight SA-314 always was scheduled to fly from Cape Town to Johannesburg. It would also be amazing to see an A330-300 at FL410 that early for such a long distance flight to Malaysia.
On Oct 21st 2025 South Africa's AIID released their final report reporting, that one crew member received serious and three minor injuries in the upset, and concluding the probable causes of the accident were:
The aircraft flew into clear air turbulence which led to the up and down oscillation of the aircraft; as a result, the cabin crew members incurred injuries as they were serving breakfast, including hot beverages, at the time.
Contributing Factor
- The PF disregarded the Airbus Pilots Operating Handbook (POH) and disengaged the autopilot without proper communication to the PM at the time of the incident.
- The aircraft weather radar did not show any significant weather in the vicinity.
- Poor Crew Resource Management
The AAID analysed:
The flight departed from Cape Town International Airport (FACT) in Western Cape province and was scheduled to stop at O.R. Tambo International Airport (FAOR) in Gauteng province.
The aircraft took off at 0620Z and climbed to FL 410. The autopilot (AP) was engaged during the climb phase and cruise phase at FL 410. The cabin crew members had started serving breakfast at the time the serious incident occurred and the seat belt sign was OFF. The cabin crew always advises passengers to keep their seat belts on even if the sign is OFF.
According to the aircrafts data report at 06:53:09Z, the aircraft was cruising at 243.3 kts (Mach 0.816) and the vertical speed was 0. At 06:53:21Z, the aircraft encountered clear air turbulence (CAT); as a result, the speed trend arrow suddenly increased and the aircraft started to gain momentum slowly. The increase and decrease occurred a few times which prompted the FO to disengage the AP at 06:53:29Z and, thereafter, she informed the captain to request a descent to FL 390 whilst she (PF) was manually engaged in recovering the aircraft from the turbulence. The aircraft recorded a maximum airspeed of 258 kts (Mach 0.860) and a vertical speed of -2176 ft/min. During this period, the aircrafts level fluctuated from 41176 ft to 40404 ft. The AP was engaged again at 06:54:13Z. The height fluctuations continued until the aircraft descended to FL 390 at 06:55:29Z.
As the cabin crew members were serving breakfast at the time of the serious incident, they suffered most injuries because they were standing. Moreover, there was no turbulence warning issued. The crew members who were in the aft galley were thrown around the cabin with food spilling off from the trolleys. Some of the injuries involved burns caused by hot beverages. Even though the passengers were startled and some screamed, none of the passengers was injured. The seat belt sign was switched to ON before the descent to FL390.
According to the official weather report, jet streams were predicted in the vicinity of the flight.
Jet streams are preferred by pilots as they save time and fuel. The report also noted that at certain areas close to the serious incident area, the upper winds were greater than 60 kts.
The winds also decreased from 100 kts at FL 360 to 80 kts at FL 410. The weather radar which was set to weather, turbulence and hazard mode (WX+T+HZD) within 40 nm in the aircraft did not show any clouds even though at lower levels there were broken clouds at a base of 3000 ft; hence, they were not aware of the turbulent condition. As a result, the cockpit crew did not alert the cabin crew about the turbulence or change the seat belt sign to ON.
The Airbus report indicated that there was a load overspeed during the turbulence but did not exceed the manufacturer limits:
- Max Calibrated Air Speed (CAS): 262 kts vs Maximum operating speed (VMO) = 330 kts.
- Max (Mach number) Mn: 0.875 vs (Maximum Mach Operating) MMO = 0.86. (ΔMn =
0.015) and duration (9s).
- Time Over Limit (TOL): 9s
- Load factors variations (during the overspeed window): 0.738G to 1.588G
This load report confirmed an overspeed (MMO) event of limited amplitude (ΔMn = 0.015) and duration (9s).
When the aircraft encountered turbulent conditions, the trend vector initial indication was towards overspeed and that is when the aircraft pitched down and, a few seconds later, pitched up, changing the trend towards Vls. The FO thought the aircraft would stall; it seemed as though the FO did not immediately recognise that they had flew into clear air turbulence (CAT). During the interview, the FO insisted that the aircraft was porpoising like riding a wave, and not in turbulence. Without confirming with the captain, the FO disengaged the AP and tried to settle the aircraft on her own, which resulted in her chasing the aircraft (chasing the aircraft means that the pilots reaction is not matching the aircrafts movement). In the Airbus report, there were four instances where the angle-of-attack was triggered and, at those times, the PFs side stick was in the nose-down direction. The report also indicated that the aircraft experienced a 0 G-load factor during that period which was likely the period when some of the cabin crew members were injured.
The captain indicated that he was unable to see the FOs input as the side stick was on his right-hand side. The FO did not follow the Airbus Flight Crew Technique Manual (FCTM) Overspeed Prevention Technique which recommends keeping the AP engaged and deploying appropriate speed brakes level if an overspeed condition is impending. The aircraft exceeded MMO for 9 seconds and triggered an overspeed warning which lasted 4 seconds but the FO said she did not hear any warnings. The captain confirmed that they received the warnings; however, due to protocol, he did not see the need to intervene since the situation was still contained. The captain may have not intervened since the FO was more experienced on the aircraft type and he may have been complacent when he assumed the PF would complete the actions required in line with the AFM. This was evident in his statement He indicated that when the turbulence started and the trend vector was pointing towards overspeed, he assumed the FO would deploy speed brakes to arrest the situation.
The simulation conducted by Airbus demonstrated that the aircraft recovers faster and the turbulence fluctuations are less when speed brakes are deployed and AP is engaged.
This article is published under license. Article Source
Published Date
