Visual separation on an Instrument approach

[tmdarlan]

My facility is discussing wether or not you can for example: tell an aircraft on an ILS approach to maintain visual seperation from A. The preceeding aircraft on an ils. Or B. Some random vfr/ifr target they are going to over fly.
I feel like you can. Just like any other application of visual. A little weird in A. Because you can just clear for the visual approach. But say they needed the ils for whatever reason.

The argument against is that if they are on an approach they arent able to maneuver to avoid the aircraft. Which seams silly to me. They can maneuver. It may create an unstable approach. But they can turn or climb or whatever if it comes to that.

Can anyone provide any reference that specifically says yes or no you can do this?

 

[MJ]

Can anyone provide any reference that specifically says yes or no you can do this?

Is there rules for using visual separation for an IFR a/c? Yes.
Is there anything prohibiting the use of above rules in said scenario? No.

 

[DankVectorz]

We’re not talking about approach controllers here. We’re talking about tower controllers working aircraft that are already established on final and talking to the tower. Maybe that’s where the confusion is

Until you said this there was no indication it was only referring to tower controllers.

 

[MJ]

If they’re maintaining visual sep behind the preceding aircraft then technically it’s a visual approach

visual separation and visual approach are not synonymous

 

[bravounite33]

An IFR at 16000 is not the same as an IFR on final. Like I said if it’s legal fine, I think it’s sketchy and wouldn’t work like that. Cleared ILS, maintain visual separation (bc I’m about to have a deal), contact tower.

1. APPROACH SEPARATION RESPONSIBILITY
2. The radar controller performing the approach control function is responsible for separation of radar arrivals unless visual separation is provided by the tower, or a letter of agreement/facility directive authorizes otherwise. Radar final controllers ensure that established separation is maintained between aircraft under their control and other aircraft established on the same final approach course.

*unless provided by the tower (not the pilot)

Visual separation is a form of separation. As a radar controller, I must provide radar separation OR visual separation the entire way down the final. IF the tower is authorized to use visual separation, then my responsibility for radar or visual separation ends when the tower is able to provide.

Wake turbulence is by far the most common reason I hear visual separation being used on the final (including keeping them on the instrument approach). The pilot accepting the visual separation instruction is taking the responsibility of dealing with the wake from the controller (they can stay higher on the approach, they can slow down, or they can do absolutely nothing if they are comfortable with it). Either way, it's not my responsibility anymore when they accepted the clearance.

 

[COWTOWN]

This is common practice all day at airports that have parallel final's not 2500 feet apart. The planes wont hit, but they will keep going their way on final on their instrument approach with less than 3 miles. Perfectly acceptable and legal.

 

[DidYouDoYourNATPRO]

I'm convinced everyone saying this isn't ok is prior military and "just doesn't like it" but can't reference any rules or explain how it's bad

fwiw I'm a pilot and do it often, usually with adjacent finals when it's hazy but not IFR. Let the planes fly how they want to, not with our arbitrary separation criteria we're so proud of for some reason

 

[Termine]

tell an aircraft on an ILS approach to maintain visual seperation from A. The preceeding aircraft on an ils

Is other approved separation ensured both before and after the application of visual separation? Is the lead aircraft smaller than a Super? Then yes, this is allowed.

. Or B. Some random vfr

Is the aircraft operating with a TRSA, or Class B/C airspace? If so, this is allowed. If not, other approved separation will not and cannot exist before and after the application of visual separation, so no, this is not allowed. But luckily you had no standard separation to lose in the first place.

/ifr target

Same consideration as the first scenario. Provided the underlying aircraft doesn't have a WT separation requirement from the overflying aircraft, as long as the overflying aircraft reports in sight, visual separation can be applied.

 

[MKK]

Why would you tell them to follow and clear them for a visual approach? Are pilots not able/allowed to maintain visual separation from an aircraft and fly an ILS approach at the same time?

That’s my thinking. I mean we use visual separation on aircraft in air on IFR flight plans. I still probably wouldn’t do it but seems like it wouldn’t be illegal

 

[OscarMike931]

‘maintain visual separation from the proceeding b737 two miles ahead, cleared ILS rwy36’. Yup there ya go, good controlling! ~sarcasm~ you suck.

Oh no the guy in the PA28 now has to fly 100 feet above the glideslope to stay out of the wake of the 737 that is outrunning him. How will he manage to land on the 8000 foot runway so high above the glideslope without overshooting.

 

[Termine]

If they’re maintaining visual sep behind the preceding aircraft then technically it’s a visual approach

I don't agree with this thinking at all. If an IFR aircraft flying at 16000 feet is cleared direct to some fix, and then later they're instructed to maintain visual with another aircraft, are they now technically VFR? Of course not. Same thing here. The pilot is still cleared to fly the procedure but they're also required to avoid hitting the guy in front.

In almost every situation, pilot visual doesn't mean that the pilot does something drastically different than they were doing before—or even that they do anything different at all. It just means separation decreases from 3 miles to 2.4 and everything is still legal.

 

[Jake Sully]

You’d call the traffic, tell them to follow and caution for the wake and clear them for a visual at that point so it’s no longer an ILS. That’s what saves you

 

[rhombus]

You’d call the traffic, tell them to follow and caution for the wake and clear them for a visual at that point so it’s no longer an ILS. That’s what saves you

Why would you tell them to follow and clear them for a visual approach? Are pilots not able/allowed to maintain visual separation from an aircraft and fly an ILS approach at the same time?

 

[rhombus]

Oh duh. Yeah 100% then tower applied visual all day lol

All day erryday unless wake is involved. Then it’s pilot applied visual or loss

 

[tmdarlan]

Everyone agrees its not great practice. But i used it trying to save a final controller from a wake turbulence bust (small behind large 3.5nm.) but theres some debate on if it would actually make it legal or not. We also have an untowered field right on our final that causes issues.

 

[tmdarlan]

You’d call the traffic, tell them to follow and caution for the wake and clear them for a visual at that point so it’s no longer an ILS. That’s what saves you

Yea they needed the ils for whatever reason. That was my first thought.

 

[tmdarlan]

Why would you tell them to follow and clear them for a visual approach? Are pilots not able/allowed to maintain visual separation from an aircraft and fly an ILS approach at the same time?

This is exactly the question im asking

 

[rhombus]

This is exactly the question im asking

You won’t find anything saying they can’t. If pilots are really worried they can always adjust their speed and/or descent rate as long as they still comply with posted altitudes on the ILS. I’m a firm believer that most pilots don’t give a shit though and will just report the traffic in sight and continue on their merry way.

 

[ManBearPig]

It's legal.

 

[rhombus]

Until you said this there was no indication it was only referring to tower controllers.

True. Rules are still the same for pilot applied vis sep though. Clearing the second airplane for a visual approach is overkill