Child Restraint Device
From Qantas.
The safest way for an infant or small child to travel on an aircraft is in a Child Restraint Device such as a car seat. Infants are allowed to be carried on your lap however research has demonstrated it does not provide the protection of a child seat.
A car seat must be pre-approved for use as a child seat at least 24 hours before departure. (my understanding is that most seats approved for cars in Aus are also suitable for aircraft) Approval of car seats cannot be obtained on departure at the airport. You must buy a seat on the plane to ensure the use of a pre-approved car seat or CARES restraint device. To buy a seat on an aircraft for your infant and get pre-approval for the use of a child seat, contact your local Qantas Office.