Some Qantas pilots are making mistakes as they return from long breaks caused by the Covid-19 pandemic, according to an internal memo reported by Australian media on Wednesday.

Among the errors listed in Qantas pilot reports: starting take-off with the parking brake on and misreading the altitude as airspeed, said a report by the Sydney Morning Herald and Melbourne's Age.

It also cited switches in cockpit panels being in the wrong position, and crew looking back at an event and "not realising that they were overloaded or had lost situational awareness".

The memo by Qantas' fleet operations chiefs reportedly said the Covid-19 related disruption to flights meant pilots had less recent flight experience, a requirement known as "recency".

As a result, the memo is quoted as saying, expert pilots "experienced a subsequent reduction in cognitive capacity".

"Airlines around the world are working through the complex process of returning to pre-Covid operations, including bringing back pilots who experienced extended periods on the ground," a Qantas spokeswoman said.

Qantas recognised very early that it needed to reassess pilots' recent and current flight time requirements as well as its "refamiliarisation programs", she said.

"We designed an enhanced return-to-work program fit for the unprecedented challenge facing our industry," the spokeswoman added.

"Safety is our number one priority and all of the data shows that our pilots are coming back with the skills and confidence to do their job safely."