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I seemingly can't find an answer to this quite obvious question: What's the preferred approach procedure for a passenger jet at a modern airport fully equipped for precision ILS (both aircraft and airport): ILS or visual approach?

If it's ILS, what would cause a visual approach to be flown (except for the ILS not working of course)?

If it's visual,

  • a. why? (ILS seems more secure from my naive standpoint)
  • b. what would be the cause to do ILS instead? Bad weather / sight for instance?

Is the decision made only by the tower or does the captain of the aircraft have any saying in it?

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    $\begingroup$ Absolutely not a duplicate question. Plenty of aircraft CAN NOT autoland, but there is still the choice between a visual approach or an ILS approach. Not the same question, and the answers won't be the same here as for that question. $\endgroup$ – Ralph J Mar 11 '15 at 23:39
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    $\begingroup$ Note, that flying visual approach does not mean ILS is not used. It just means visual contact is required. Most pilots will still use ILS for cross-check if it is available. $\endgroup$ – Jan Hudec Jan 11 '16 at 5:55
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I'll give the answer from an ATC perspective. A visual approach is the most preferred approach, since we can get aircraft to follow each other, and don't have to worry as greatly about aircraft getting too close. The rules say we can compress under certain conditions to 2.5 miles on ILS or radar separation approaches, but timing wise, for the runway to be clear, you can often need less separation between aircraft to maximize its usage. With the visual approach, you're vectoring to keep aircraft closer so they can see each other and follow in closely to each other to the runway.

In most ATC facilities, the Tower decides what runway to use, and the approach control calls the type of approach generally on offer(this can vary depending on facilities and how they agree to run things). A pilot can always request a different approach... they might be delayed, sometimes significantly if they insist on something way out of the loop.

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  • $\begingroup$ That's an interesting addition on the answers given in the duplicate that I missed, thank you very much! $\endgroup$ – asco Mar 10 '15 at 23:58
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Given the caveat that I retired in 1999 and cannot speak for today's pilots, my thinking and the observed preferences of the great majority of the pilots I flew with follow.

With few exceptions, a visual approach was preferred over an ILS for the simple reason that it's usually quicker, and over time in large aircraft, the fuel savings can be significant for your company. I did know a few pilots, though, that liked to stay in the air longer to increase the size of their paycheck when being paid by the flight hour. I always felt this was unprofessional. A 747-100/200 (my airplane for my final 10 years) burns a lot of fuel, and part of the captain's responsibility is not costing the company money if you don't have to. Also, if you have people in the back making connections, you want to maximize the time they'll have to make those connections.

There are times, though, even with CAVU conditions, you may want the ILS. For example, I was offered the visual approach one night into Hunter Army Airfield in Savannah, Georgia. It was my first time there, and locating the runway in the maze of lights made it unwise to accept. In fact, I found that airfield so hard to find visually at night, that I continued asking for the ILS until I had been there several times.

Of course, if it's clear, but you're going into LAX on a hundred mile final from the east with 15 or more aircraft doing the same, you don't even think about a visual.

Generally I followed the practice of requesting a visual approach when first possible going into familiar airports when the traffic was light and there was time to be saved.

There were pilots of foreign airlines that would never request a visual. For example, Japan Air and Korean Air going into Anchorage in the early 1990s always requested an ILS. If it wasn't available, they would request a VOR approach. As I understand it, their training, culture, and experience (as explained to me by a JAL check captain) didn't favor being able to just look at a runway and land.

It's a minor point, but to me visual approaches offered more opportunities to play.

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  • $\begingroup$ I also preferred the visual. I made a habit of calling out visual contact with the airplane in front of me ("Newark tower, jetlink 1234 with the 737 traffic over TEB in sight"), which usually got me the visual clearance. I'm also sure the guys at the EWR tower were happy to be relieved of spacing concerns (particularly when they'd squeeze us onto 11 in between the 22L/4R arrivals). $\endgroup$ – casey Jan 10 '16 at 3:53
  • $\begingroup$ even on the visual, many large airports with straight in approaches (eg, NOT JFK), will tell the pilot, "turn left 020, intercept the localizer, descend and maintain 3,000". so even though you're officially on the visual, you're still tracking the localizer. Other airports have published visuals with waypoints, like SFO Quiet Bridge globalair.com/dtpp/globalair_00375QUIETBRIDGE_VIS28LR.PDF $\endgroup$ – rbp Jan 10 '16 at 20:55
  • $\begingroup$ What makes a visual approach quicker than an ILS approach? As a non-pilot, I can't see why there would be any difference, speed wise? $\endgroup$ – Gavin Coates Jan 11 '16 at 12:15
  • $\begingroup$ @GavinCoates The first sentence of your comment would make a good regular question and thus allow for a full answer. A short answer is that there are a number of things. Perhaps easiest to understand is the situation where you are, say, coming in from the south and the runway in use is landing to the south. If you fly an ILS approach, you're going to be taken to a point at least 5 miles north of the airport before turning back. If you're on a visual, you need to get only as far north of the airport to allow a turn back. One mile would be sufficient. Ask as a question and I'll give more detail. $\endgroup$ – Terry Jan 11 '16 at 19:07
  • $\begingroup$ @Terry done: aviation.stackexchange.com/questions/24275/… $\endgroup$ – Gavin Coates Jan 12 '16 at 11:12

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