SINGAPORE: Australian safety authorities confirmed that the crew of a Malaysia Airlines flight took off from Brisbane Airport without noticing that the plane's pitot probes were covered, resulting in "unreliable airspeed indications".
In the incident on Jul 18 this year, the Airbus A330-300 left Brisbane for Kuala Lumpur but ultimately had to turn back and land, according to the preliminary report published by the Australian Transport Safety Bureau (ATSB) on Thursday (Aug 30).
The incident resulted in the main runway of the airport being closed for 90 minutes, according to The Australian. No injuries were reported.
A subsequent inspection revealed that the covers were still fitted over the aircraft's three pitot probes after it landed.
"This resulted in unusable airspeed information being displayed to the flight crew," said ATSB.
Pitot probes measure air pressure to assess speed, and are ineffective if they are blocked.
The ATSB report noted that Brisbane Airport recommends that pitot probes be covered while planes are on the ground, as wasps in the area have been known to build nests in the openings and block them.
The covers have long red tags attached to them that read "remove before flight".
However, both the operator's maintenance engineer and the captain did not notice the pitot covers during separate external aircraft inspections. Nor did the ground handlers spot the covers, the ATSB report said.
The crew later said that they did not routinely use the pitot covers on a turnaround, and that the airline did not normally fly to airports where the use of such covers was standard, the report noted.
ATSB Chief Commissioner Greg Hood said unobstructed pitot probes are critical to flight safety.
"This is a serious incident. The CCTV footage reveals that the three pitot covers were in place on the aircraft as it pushed back from the terminal and as it accelerated down the runway," he said.
"This limited the amount of information – the critical information – that is available to flight crew during the take-off and during the short flight, up to 10,000 feet, and then the return to Brisbane Airport where the aircraft landed safely.”
He added that the ATSB was issuing a safety advisory notice to all operators to take "particular care".
“Today we are issuing a safety advisory notice to all operators to take particular care and review their procedures for the fitment of pitot covers on landing at Brisbane Airport and ensure their processes are robust for the removal of these covers prior to flight,” he said.
“Our investigation is continuing. We will be focusing specifically on the procedures for flight crew and ground crew in relation to the pre-flight checks for the aircraft, and also the cockpit warning systems received by the flight crew as they accelerated down Runway 01.”
There have been multiple reports of insect activity disrupting aircraft systems at Brisbane Airport, according to ATSB.
A preliminary review of the ATSB database indicated that, from 2008 to 2018, there were at least 15 incidents involving "high-capacity regular public transport aircraft" departing from Brisbane Airport where one of the pitot probes had a partial or total blockage, at least four of which were identified as insect nests, according to ATSB.
These resulted in three rejected take-offs, four aircraft returning to Brisbane Airport after continuing the take-off and one aircraft that continued to its destination.