The way aircraft are operated in day-to-day operations may also present impacts in terms of the noise that reaches the ground. ICAO assists on the development and standardization of low noise operational procedures that are safe and cost-effective. The possibilities include noise preferential runways and routes and noise abatement procedures for take-off and landing. The appropriateness of any of these measures depends on the physical lay-out of the airport and its surroundings, but in all cases the procedure must give priority to safety considerations.
ICAO's recommendations on operational procedures are contained in several documents: