SINGAPORE: Several safety issues were raised by Australian authorities over a 2022 incident involving a Singapore Airlines (SIA) plane that was about to depart Brisbane for Singapore, including the discovery that the Airbus A350’s pitot probes were still covered minutes before take-off.
Pitot probes provide airspeed data to aircraft systems and flight crew, which is especially important during take-off and initial climb. If partially or completely blocked, airspeed indications will be inaccurate.
During turnarounds at Brisbane, pitot probes are covered to prevent nesting mud wasps from blocking the tubes, which can occur in as little as 20 minutes. The covers must be removed prior to take-off.
In the incident on May 27, 2022, a refueller in a bay next to the SIA jet noticed that the pitot probes were still covered before take-off, said the Australian Transport Safety Bureau (ATSB) in its final report on the incident released on Mar 15.
A licensed aircraft maintenance engineer responsible for the aircraft’s turnaround was alerted to this and removed the pitot covers two minutes before the scheduled departure time.
The aircraft subsequently proceeded for its planned departure to Changi Airport without further incident, ATSB said.
The bureau highlighted a serious incident in 2018, when a Malaysia Airlines A330 took off from Brisbane with its pitot covers still in place. As a result, its crew had to conduct an emergency return landing without airspeed data.
In the incident involving SIA's jet, it was found that the airline’s contracted engineering provider at Brisbane, Heston MRO, had yet to implement “an acceptable method for accounting for tooling and equipment prior to aircraft pushback”.
“Additionally, the procedural risk controls which were in place for the removal of the pitot probe covers were circumvented when the licensed aircraft maintenance engineer certified for their removal in the technical log and removed a relevant warning placard from the flight deck, without visually or verbally confirming that they had been removed,” ATSB chief commissioner Angus Mitchell said.
The engineer or headset operator also did not perform the final walk-around inspection of the aircraft to ensure that it was correctly configured for flight with all panels and doors closed, and covers removed.
“This incident demonstrates how assumptions and procedural omissions can lead to unsafe conditions; in this case, the potential for an aircraft to take off with erroneous or absent airspeed indications,” Mr Mitchell said.
The investigation also noted that the engineer had reported that his workload in his dual role as an aircraft maintenance engineer and regional manager had become "considerably more demanding" following the COVID-19 pandemic.
Heston MRO did not track the work-related hours of personnel with dual roles like the engineer involved in this incident for fatigue calculation purposes, Mr Mitchell said.
“This meant there was an increased risk of a fatigue-related incident with these personnel,” he added.
However, the bureau was unable to formally establish that fatigue contributed to what happened.
It also found that the pitot probe covers fitted to the aircraft were about 3m above eye level and had relatively short streamers that were not clearly visible. Streamers are flags or ribbons attached to pitot covers and are intended to alert personnel of their presence.
Additionally, a review of closed-circuit television footage (CCTV) of SIA turnarounds at Brisbane Airport found that the majority of flight crew pre-flight inspections observed around the time of the incident were truncated and not undertaken in accordance with company procedures.
SIA’s procedures require flight crew to conduct an exterior aircraft inspection, or walk-around, about 30 minutes before departure.
“The pre-flight walk-around occurs before the pitot probe covers are to be removed, so this did not contribute to (the May 27) incident,” Mr Mitchell noted.
“Nonetheless, it was identified in our investigation as a safety issue, which Singapore Airlines has subsequently addressed.”
Following this incident, Heston MRO no longer requires the Brisbane regional manager position to undertake dual responsibilities, which included aircraft maintenance certification requirements.
It also now tracks the work hours of all employees for fatigue management purposes.
The report also noted that SIA has communicated to its flight crew about the requirements of their pre-flight walk-around checks and why they are important.
SIA has also provided Heston MRO at Brisbane with pitot probe covers that have longer streamers so that they are more visible.
CNA has reached out to SIA for more information.
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Pitot probes provide airspeed data to aircraft systems and flight crew, which is especially important during take-off and initial climb. If partially or completely blocked, airspeed indications will be inaccurate.
During turnarounds at Brisbane, pitot probes are covered to prevent nesting mud wasps from blocking the tubes, which can occur in as little as 20 minutes. The covers must be removed prior to take-off.
In the incident on May 27, 2022, a refueller in a bay next to the SIA jet noticed that the pitot probes were still covered before take-off, said the Australian Transport Safety Bureau (ATSB) in its final report on the incident released on Mar 15.
A licensed aircraft maintenance engineer responsible for the aircraft’s turnaround was alerted to this and removed the pitot covers two minutes before the scheduled departure time.
The aircraft subsequently proceeded for its planned departure to Changi Airport without further incident, ATSB said.
The bureau highlighted a serious incident in 2018, when a Malaysia Airlines A330 took off from Brisbane with its pitot covers still in place. As a result, its crew had to conduct an emergency return landing without airspeed data.
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WHAT INVESTIGATIONS FOUND
In the incident involving SIA's jet, it was found that the airline’s contracted engineering provider at Brisbane, Heston MRO, had yet to implement “an acceptable method for accounting for tooling and equipment prior to aircraft pushback”.
“Additionally, the procedural risk controls which were in place for the removal of the pitot probe covers were circumvented when the licensed aircraft maintenance engineer certified for their removal in the technical log and removed a relevant warning placard from the flight deck, without visually or verbally confirming that they had been removed,” ATSB chief commissioner Angus Mitchell said.
The engineer or headset operator also did not perform the final walk-around inspection of the aircraft to ensure that it was correctly configured for flight with all panels and doors closed, and covers removed.
“This incident demonstrates how assumptions and procedural omissions can lead to unsafe conditions; in this case, the potential for an aircraft to take off with erroneous or absent airspeed indications,” Mr Mitchell said.
The investigation also noted that the engineer had reported that his workload in his dual role as an aircraft maintenance engineer and regional manager had become "considerably more demanding" following the COVID-19 pandemic.
Heston MRO did not track the work-related hours of personnel with dual roles like the engineer involved in this incident for fatigue calculation purposes, Mr Mitchell said.
“This meant there was an increased risk of a fatigue-related incident with these personnel,” he added.
However, the bureau was unable to formally establish that fatigue contributed to what happened.
It also found that the pitot probe covers fitted to the aircraft were about 3m above eye level and had relatively short streamers that were not clearly visible. Streamers are flags or ribbons attached to pitot covers and are intended to alert personnel of their presence.
Also read:
TRUNCATED PRE-FLIGHT INSPECTIONS
Additionally, a review of closed-circuit television footage (CCTV) of SIA turnarounds at Brisbane Airport found that the majority of flight crew pre-flight inspections observed around the time of the incident were truncated and not undertaken in accordance with company procedures.
SIA’s procedures require flight crew to conduct an exterior aircraft inspection, or walk-around, about 30 minutes before departure.
“The pre-flight walk-around occurs before the pitot probe covers are to be removed, so this did not contribute to (the May 27) incident,” Mr Mitchell noted.
“Nonetheless, it was identified in our investigation as a safety issue, which Singapore Airlines has subsequently addressed.”
WHAT HAS BEEN DONE
Following this incident, Heston MRO no longer requires the Brisbane regional manager position to undertake dual responsibilities, which included aircraft maintenance certification requirements.
It also now tracks the work hours of all employees for fatigue management purposes.
The report also noted that SIA has communicated to its flight crew about the requirements of their pre-flight walk-around checks and why they are important.
SIA has also provided Heston MRO at Brisbane with pitot probe covers that have longer streamers so that they are more visible.
CNA has reached out to SIA for more information.
Continue reading...