Departure WT sep

[MJ]

Is miles between successive departures no longer a thing? Haven't been able to find it.

 

[MJ]

Right but the heavy isn't on an instrument approach... I've always read that as apply that separation to AC operating behind an AC on an instrument approach... Or... Apply that separation to AC on an approach/following an AC on an instrument approach

1. operating directly behind or,
2. following an aircraft conducting an instrument approach

The PCG defines directly behind, and makes an exception in the case of wake turbulence application, which it is the redefined in g1 and the note. If they’re on final to parallels less than 2500’ apart, for wake turbulence application the trail aircraft is directly behind the lead.

Turn your scenario around a little and have the heavy on a straight-in while the large is on a downwind doing pattern work. Large never reports the heavy in sight....when is it legal to tell the large to turn base?

Using 2-1-19b and 2-1-20....which references AC 90-23G


The part saying "if you have visual contact with the larger aircraft" wouldn't even be included if a mileage was required since the wake turbulence would have dissipated by the time the trailing aircraft reaches the same point using mileage.

5-5-4 mentions:
"When operating within 2,500 feet of the flight path of the leading aircraft over the surface of the earth and less than 1,000 feet below"

Unless the large was 300 feet below the heavy, that doesn't apply either in your situation.

5 miles in trail or lead a/c across the threshold.

The AC isn’t regulatory. It’s just to inform and teach avoidance/mitigation technique. Has nothing to do with our requirements.

Anything higher than 1000’ below is less than 1000’ below. Same altitude or above is still less than 1000’ below.

 

[Stinger]

Anything higher than 1000’ below is less than 1000’ below. Same altitude or above is still less than 1000’ below.

I'm an idiot, going by what I posted if someone is 300 feet above, there's never mileage to apply on final. I knew that couldn't make sense haha

5 miles in trail or lead a/c across the threshold.

So at the moment the heavy crosses the threshold, the large can be on base about to turn a one mile final and it would be legal even if the large never reports the heavy in sight?

I see what you're getting at with Class C and mileage, but to me these rules make no sense in a tower environment. I think the tower rules are separate from the radar rules in most cases.

Would the original situation with the heavy in front of large on parallel runways be legal in a Class D tower? What about if the tower is able to apply the 2 increasing to 3 rule for departures.....does that change the arrival requirements?

 

[MJ]

So at the moment the heavy crosses the threshold, the large can be on base about to turn a one mile final and it would be legal even if the large never reports the heavy in sight?

I see what you're getting at with Class C and mileage, but to me these rules make no sense in a tower environment. I think the tower rules are separate from the radar rules in most cases.

Would the original situation with the heavy in front of large on parallel runways be legal in a Class D tower? What about if the tower is able to apply the 2 increasing to 3 rule for departures.....does that change the arrival requirements?

Yeah. It all comes down to who's responsible for separation... ATC or the Pilot. In B and C ATC is required to ensure that WT sep exists, in D the IFR is only provided sep from other IFR, otherwise they're on their own. Think of an uncontrolled airport... you could have a dozen heavies flying in the pattern and approach couldn't care less. That IFR has the same responsibility there as in the D.

 

[ajmezz]

I'm confused as to why he would turn the H in front of the L to begin with, but everyone has their reasons. To the original post, he didn't apply 7-2-1 correctly to begin with. You need approved WT sep before and after the application of vis sep. If he had that, then after the L calls the H in sight, he still needs to tell them to maintain vis sep, unless the pilot calls traffic in sight and will maintain vis sep, at which point he could just say approved/vis sep approved.

 

[Homsar]

1. operating directly behind or,
2. following an aircraft conducting an instrument approach

You added that comma, though, which I feel changes the wording of the passage. If what you wrote were how they intended it to be read, it should be written like this:

“g. Separate aircraft operating directly behind an aircraft, or following an aircraft conducting an instrument approach, by the minima specified and in accordance with the following”

I read the way it’s originally written as only applicable to aircraft either behind or following an aircraft on an instrument approach, not an aircraft behind another always. If they wanted both, why not add “an aircraft” after “behind?” It’s written as to define two ways that separation behind an instrument approach aircraft would apply, either directly behind or following, as in “directly behind” the first aircraft in a straight line or “following” not in a straight line, where you would then use flying miles.

 

[wikdevo]

Revisiting this topic.
Heavy in the vfr pattern doing touch and goes, with full length departures. Can you apply mileage, and if so, how?

if you're using mileage it would be between two radar identified targets it's in the radar section.

 

[eltors0]

7-4-1 A visual approach is an ATC authorization for an aircraft on an IFR flight plan to proceed visually to the airport of intended landing; it is not an instrument approach procedure. Also, there is no missed approach segment. An aircraft unable to complete a visual approach must be handled as any go-around and appropriate separation must be provided.

The heavy is on the left side doing VFR pattern work. The a320 is going to the right side on the visual. That is not directly behind. The a320 is not on an instrument approach procedure. Issue the cautionary.


5-5-4 has no application in this given scenario (and in my opinion, 5-5-4 only applies to 3-9-6 e. Even with that reference, it states that 5-5-4 may be applied in lieu of the time based wake turbulence separation between successive departures..

Even if tower decides to jam the heavy in front of a straight in visual to the same runway with a smaller weight cat (L/S+/S), you are required to issue the cautionary.

 

[eltors0]

if you're using mileage it would be between two radar identified targets it's in the radar section.

3-9-6 e

 

[wikdevo]

3-9-6 e

yes 5-5-4 radar minima

 

[MJ]

if you're using mileage it would be between two radar identified targets it's in the radar section.

To be nit picky, it’s one of the few exceptions where it’s not with two ID’d targets. One ID’d and one anticipated ID’d.

1. An aircraft taking off and another radar identified aircraft when the aircraft taking off will be radar-identified within 1 mile of the runway end.

That is not directly behind.

It is directly behind. It’s defined specifically for wake turbulence application as such.

 

[Rjb301]

I'm confused as to why he would turn the H in front of the L to begin with, but everyone has their reasons. To the original post, he didn't apply 7-2-1 correctly to begin with. You need approved WT sep before and after the application of vis sep. If he had that, then after the L calls the H in sight, he still needs to tell them to maintain vis sep, unless the pilot calls traffic in sight and will maintain vis sep, at which point he could just say approved/vis sep approved.

This is what I would like to know as well. Especially since there was nothing behind the air bus to conflict with the heavy. The controller that was working is using 2-1-19 to explain why he didn't have a bust. He is saying that the visual approach part makes it ok for him to just issue the traffic, have the airbus report it in sight, and issue a cautionary and go about his day. Personally, anytime I issue traffic and the aircraft reports it in sight, maintain visual separation automatically follows. We all know how much covering our ass is a part of this job.

2−1−19. WAKE TURBULENCE

a. Apply wake turbulence procedures to an aircraft operating behind another aircraft when wake turbulence separation is required.

NOTE−

Para 5−5−4, Minima, subparagraphs g and h specify the required radar wake turbulence separations. Time-based separations are contained in Para 3-9-6, Same Runway Separation, Para 3-9-7, Wake Turbulence Separation for Intersection Departures, Para 3-9-8, Intersecting Runway Separation, Para 3-9-9, Nonintersecting Converging Runway Operations, Para 3-10-3, Same Runway Separation, Para 3-10-4, Intersecting Runway Separation, Para 6-1-4, Adjacent Airport Operation, Para 6-1-5, Arrival Minima, and Para 6-7-5, Interval Minima.

b. The separation minima must continue to touchdown for all IFR aircraft not making a visual approach or maintaining visual separation.

 

[wikdevo]

To be nit picky, it’s one of the few exceptions where it’s not with two ID’d targets. One ID’d and one anticipated ID’d.


It is directly behind. It’s defined specifically for wake turbulence application as such.

yea, i suppose but by the time the second jet tags up you better have your mileage lol.. or time. in my experience. the mileage might save you 5-10 seconds.

 

[Homsar]

The controller that was working is using 2-1-19 to explain why he didn't have a bust. He is saying that the visual approach part makes it ok for him to just issue the traffic, have the airbus report it in sight, and issue a cautionary and go about his day.

Like I and others said, though, I feel like he's right. 2-1-19 only says to apply it if it's required, and how I read 5-5-4 g c 1 2, since the heavy is not on an instrument approach, with a large behind it, a cautionary is the only requirement. Smart? No. Clean? Yes.

[Edit to add] Cautionary is definitely required per 3-10-3 b:

Issue wake turbulence advisories, and the position, altitude if known, and the direction of flight of:

1. The super or heavy to aircraft landing behind a departing/arriving super or heavy on the same or parallel runways separated by less than 2,500 feet.

Funny enough, on page 30 of this PDF, it mentions a 2 minute WT requirement for both departures and landers behind a heavy conducting a Low Approach, Missed Approach or Touch-and-Go Landing, but the current 7110 only specifies the 2 minute requirement on departures.

 

[Stinger]

Personally, anytime I issue traffic and the aircraft reports it in sight, maintain visual separation automatically follows.

I hope you're exaggerating with this part. If you're telling a VFR to maintain visual separation at any time other than doing pattern work behind a larger weight class departure, you're giving instructions that mean nothing.

 

[MJ]

since the heavy is not on an instrument approach

ok so we have:
1. operating directly behind or,
2. following an aircraft conducting an instrument approach

It still applies.

 

[DL0509]

You dont have to say "Maintain Visual Separation" do you? I thought if you are just giving a caution wake turb call after he has him in sight, the pilot has to be able to apply visual separation, not that it actually has to be said.

 

[Homsar]

ok so we have:
1. operating directly behind or,
2. following an aircraft conducting an instrument approach

It still applies.

Operating directly behind what? You’re ignoring my posts detailing how you’re altering the meaning of the sentence.

 

[MJ]

The lead aircraft... I'm not altering the meaning of the sentence, I'm breaking it up to try and explain it to you. You are grouping "directly behind or following" into one thought using two different descriptors, and this is wrong. The trail a/c does not have to be following a lead on an instrument approach. 5-5-4 is applied in all radar environments, not just final approach. So if the trail a/c is directly behind, OR following an aircraft on an instrument approach, which it may not be directly behind, those sep's standards are applied.

It's my day off and I'm about to start drinking so we need to resolve this otherwise I can't responsible for future posts

 

[Homsar]

I can’t think of any other example in the 7110 where the word “aircraft” is absent, yet you’re supposed to assume it is being referenced as such. The words “the lead aircraft” do not appear in that sentence, it’s instead describing two positions relative to an aircraft on an instrument approach: directly behind, or following. It doesn’t make grammatical sense to break it up the way you do, especially when you’re adding words and commas that don’t appear in the text.

 

[Stinger]

There'll never be an agreement on this topic. I saw it on stuckmic about 7 years ago and it was the same responses as it is now.
Just go with what you're comfortable with since the 7110 says to use best judgment in one of the first paragraphs.

Note at the end of 3-1-9:
NOTE− Unless otherwise authorized, tower radar displays are intended to be an aid to local controllers in meeting their responsibilities to the aircraft operating on the runways or within the surface area. They are not intended to provide radar benefits to pilots except for those accrued through a more efficient and effective local control position. In addition, local controllers at nonapproach control towers must devote the majority of their time to visually scanning the runways and local area; an assurance of continued positive radar identification could place distracting and operationally inefficient requirements upon the local controller. Therefore, since the requirements of para 5−3−1, Application, cannot be assured, the radar functions prescribed above are not considered to be radar services and pilots should not be advised of being in “radar contact.”