SIDs and STARs
In the last lesson, we appreciated how an orderly IFR departure from busy airports using Standard Instrument Departures (SIDs) is the safest option. The same problems of congestion exist for inbound flights and perhaps the need for such a systematic approach is even more critical given that IFR aircraft are approaching with much lower fuel levels than departing aircraft. This is the realm of the Standard Terminal Arrival Route (STAR).
A problem develops
Let's again picture a busy airport with a mix of general aviation, charter and regular public transport IFR flights scheduled to arrive during the morning rush hour. The sad and increasingly stressed air traffic controller is trying to juggle varying ETAs, approach speeds, altitudes, directions etc and plan to have them all touchdown with minimal delay while maintaining relevant aircraft separation standards. No wonder we would rather fly the aircraft.