I live close to indianapolis and have been listening to the atc online.I was just wondering why are they always doing visual approaches?That's all i hear them say on there when talking about approaches.
A number of reasons here.
First, traffic conditions allot for it. Just because an airport has instrument approaches for runways doesn't mean they must always be used. In most cases in the US, visual approaches are even preferred over instrument approaches. Only places where I've seen instrument approaches used first and foremost are JFK and LAX, and even in LAX's case, they may be given the ILS approach first, but as they get closer to the field, pilots are asked to point out traffic converging. If they see it, they are told to follow the traffic and be cleared for a visual approach.
Second, comes the responsibility of separation on the approach. In an instrument approach, that responsibility lies totally on ATC. With a visual approach, the pilot is responsible for his/her separation. This gives ATC the ability to handle more traffic in the arrival stream/corridor, and sequence them in easier.
Third is weather. if the field is VMC, why not? Most times, you can see the field from a good 20nm out, depending on conditions at the field. There may be times where they may need to use the instrument approach (for example, you're landing west, it's late afternoon, and the sun is in your eye). This happens more times than not at places like LAS or PHX, where they would use the instrument approach at times like that. Or if visibility is the issue, then it's best to go with instrument approaches.
So there's a number of factors to go along with instrument vs. visual, but that's the bulk of it. I'm sure other controllers would love to chime in on this with their experiences.