"Combined with reduced flying across the network, we recognise a flow-on effect for flight crew's focus and familiarity with the operation," the memo stated.
"Routine items that used to be completed with a minimum of effort now occupy more time and divert attention away from flying the aircraft."
Qantas' flight operations team are responsible for supervising the performance of aircrafts and pilots; a task they believed was "especially important" after 19 months of disrupted operations.
The news follows a warning issued by the Air Accident Investigations Branch (AAIB) in December about how pilots could be at risk of making small mistakes due to fewer flying hours.
One such incident involved a TUI Airways flight in September, which spawned a preliminary report by AAIB. The branch found that the pilots had experienced "significant periods without flying in the preceding 18 months".
Despite completing flight simulator sessions during the pandemic, the AAIB warned that these don't fully "replicate moments of high crew workload".
Similarly, in the United States, the US Aviation Safety Reporting System released a report noting 128 incidents of pilot mistakes between March 2020 and June 2021 due to 'lack of flying'.
In the report, one pilot admitted he forgot to lower the plane wheels when landing, managing to pull them out just 250 metres from the tarmac.