Originally Posted by
J.O.
As an example, you are approaching the airport from the west and landings are on runway 27. You’re on radar vectors and ATC has you descend to 3,000 ft when you’re 10 miles to the west to get you below the departing traffic (an inefficient plan but one that does occur from time to time). The base leg turn point is 8 miles from the runway, meaning you have over 20 track miles to go. That’s a long distance to fly with slats / flaps deployed to stay below 200 kts. The intent is to allow you to stay at minimum clean airspeed until you start extending slats / flaps for the approach.
At many (most?) busy international airports it's routine to fly at less than 200kts for the last 20+ miles. Typical profile has one at 210kts until about 20 miles, 180 until 10, 160 until 4 or 5 miles. Depends on where in the world you are: in the UK they tend to use holds to meter the traffic, in the US they prefer to use delay vectors and speed control.
In practical terms there's no way around flying with some slats/flaps out at ranges more than 10nm.