The Qantas jumbo eventually took off on the 12-hour flight to Chile about 45 minutes late.

While a sign of strong demand for flights, pilots say the airline’s high utilisation of aircraft is placing pressure on crewing. And it also raises the likelihood of disruptions to flights when aircraft encounter significant technical problems.

All standby crew have been used and SMS messages sent plus management pilots contacted. There’s no one.

Qantas manager of base operations

On Friday, a Qantas A330 bound for Bangkok turned back to Sydney Airport shortly after take off when one of its two engines suffered a “high vibration event”.

The plane circled Sydney before landing safely about an hour after departing. Passengers on QF23 were later put on a replacement plane bound for Bangkok, but the affected A330 remains grounded at Sydney to allow for the engine to be replaced.

And late on Friday night, another Qantas A330-300 bound for Hong Kong was forced to remain on the ground at Brisbane Airport due to a flight-control malfunction, resulting in a three-hour delay.

“Due to the increased utilisation and complexity in the A330 network, I would expect there to be ongoing delays for the next few days due to these two events,” Qantas’ deputy manager for Airbus fleet operations told pilots in an email on Saturday.

“This is unfortunately going to result in some roster disruptions.”

The senior manager said the A330 engine’s “high vibration event” above Sydney on Friday bore similarities to an engine problem on an aircraft departing Brisbane recently.

“We will be investigating the cause and provide information to you as soon as possible,” he said in the note.

At the weekend, six international flights were delayed by an average of about three hours.

Qantas said in a statement that airline schedules were finely tuned and, while it had a level of redundancy to help recover quickly if an aircraft had unexpected technical issues or crew suddenly became unwell, it sometimes did cause delays.

“Qantas is undertaking one of the largest pilot recruitment programs in its history, with
150 pilots to be recruited into Qantas and QantasLink in the next financial year,” it said.

Qantas plans to open a pilot academy next year capable of training up to 500 pilots annually.