Wake turbulence with pattern traffic

[creepstreets]

We had a scenario come up, and there was a bit of a debate regarding wake turbulence for an aircraft in the pattern.

We had a large that was on a visual approach to the runway on right downwind. At the same time, we had a small on left downwind in the pattern. The large turned base, and we pointed out the traffic to the small so that he could follow the large in to the runway. If the small did NOT get the large in sight, would the small require the 4 miles in trail behind the large in 7110.65 5.5.4I?

 

[AZNLUVR69]

FAA Up/Down?

Both are tower only class Charlie. Approach is ran by a different facility at both.

 

[MJ]

No.

Yes. How would you provide radar services as required if there is no radar identification?

Both are tower only class Charlie. Approach is ran by a different facility at both.

Yeah that makes sense. You might not be delegated any responsibilities or authoritah. I'm don't know details on how a tower only in a C surface area is handled, but I can't see how there aren't SOME radar functions you can't perform, you have to be able to do to meet class C requirements. Limited radar services/class c services is how I've seen it described in LOAs.

Corpus approach has that relationship w/ Harlingen, maybe someone from there can add some insight.

 

[slater]

If they have a certified radar display. Tower can provide radar services as stated in the SOP.

 

[ManBearPig]

Yes. How would you provide radar services as required if there is no radar identification?

A) Serious question, have you worked at tower in Class C and had pattern traffic? I have. And worked pattern traffic at it almost every day I was in the tower.

B) Where in "Class C Services" does it say "radar"?

Tower applied visual separation does not require a radar ID. Pilot applied visual separation satisfies 5-5-4 wake turbulence minima, as well as not operating directly behind the lead landing "wake generating" aircraft.

You think DAB is radar IDing the 18 Riddle aircraft in their pattern after every touch and go??

 

[PrisonMike]

We’re just going to ignore para 2-1-20 wake turbulence cautionary advisories in this tread.

Got it.

 

[32andBelow]

False. False false false. "Visual separation may be applied when other approved separation is assured before and after the application of visual separation." If you don't have radar ID, you don't have visual separation (unless you can make it work using Chapter 6 rules).


Yes. I don't think they're issuing the "radar contact" phraseology, but if LC is radar certified (which they should be) then the aircraft are radar identified by application of 5-3-2a. Or heck, 5-3-2c and the crosswind turn.

Yah the center or tracon applies radar before the tower takes over visually

 

[ManBearPig]

We're talking about Class C pattern traffic here. A VFR departs and is in the pattern; they fly a tight downwind for whatever reason and their target gets close to the target of an IFR guy short final.

Class C services include separation between the IFR and the VFR. If someone asks LC "what separation were you using" of course they will say "tower visual." Again, visual separation (tower or pilot) requires the assurance of other separation before and after the visual separation. What separation was LC using before visual? Target resolution. Target resolution is a form of radar separation and requires that both aircraft are (or are about to be) be radar identified. How was the VFR pattern traffic identified? The TRACON sure as hell didn't identify them using 5-3-2a because the TRACON never received a rolling call. So LC has to have identified them somehow.

JFC. I'm going to ask this to you, too. Do you work at a tower in Class C airspace??

No one is saying radar contact to someone in the VFR traffic pattern. The aircraft is in sight the entire time. You are massively over thinking this.

And because someone posted in above, you can't just think "radar contact" in your head, and have it count. You have to say it.

 

[Termine]

I'd say SRS before and after visual

You can transition from SRS directly to tower visual if you have the inbound in sight from the moment the pattern guy leaves the runway. You're right, in many/most situations that will be the case. But I can come up with perfectly plausible and legal situations where you don't have the inbound in sight at the moment the VFR leaves the runway.

In Class C we must separate IFRs from VFRs. Defined minimum separation at all times, 500' or target resolution or visual, not just WT sep when the small is passing behind. Yeah, if the VFR has just rotated and the IFR is on a five-mile ILS then obviously they aren't going to hit. But "come on, obviously they aren't going to hit" is not an approved form of separation. Target resolution is an approved form of separation.

Do you work at a tower in Class C airspace??

Yes.

No one is saying radar contact to someone in the VFR traffic pattern.

I agree.

You have to say it.

I disagree. Proper application of 5-3-2a/b/c or 5-3-3a/b/c/d is necessary and sufficient to consider an aircraft radar identified. The identification process is entirely contained within those paragraphs. There is a separate requirement to "inform" the pilot when initial radar identification is established, but that is an informational requirement and nothing more. It does NOT have any procedural significance. Not saying "radar contact" will not lead to a loss; their radar identification is established as soon as you have completed one of the seven radar ID requirements.

 

[AB19]

MJ definitely didn’t work at a level 8 up down that’s a class Charlie with lots of military in the tower pattern what would he know about anything

 

[rhombus]

Im still stuck on the no wake turb in deltas… my facility is gona have some heated convos this week…

How are we getting around 3-9-6 and the arrival version? Deltas can still use time. And i argue if you got a certified tower display you can still use miles. Thats the whole point of it.

3-9-6 is about runway separation and has nothing to do with airspace. You follow those rules regardless of what class of airspace you are in

 

[Termine]

3-9-6 is about runway separation and has nothing to do with airspace. You follow those rules regardless of what class of airspace you are in

Can you point to where the book says that?

I mean obviously you do it, I do it, we all do it. We provide same-runway sep because we have to and I'm not saying we shouldn't... but what's the textual justification for providing SRS between two VFRs at a Delta? Putting the pieces together, same-runway separation is a kind of separation. It's right there in the name. And according to the pilot/controller glossary, at a Delta there is no separation service provided between VFRs.

Just one of those things that they haven't gotten around to spelling out in the book because nobody has been annoying enough to force them to, I guess.

 

[Termine]

Runway sep is a requirement regardless of airspace, and the "no separation service" you're referencing is in regards to airspace requirements.

I believe you from a common-sense and "everyone does it this way" standpoint. I'm not about to go to work and launch a VFR Twin Cessna with 2000-and-airborne behind a Skyhawk. Obviously.

But do you have a textual reference for that statement? 7110.65, 7210.3, ICAO PANS-ATM, anything?

 

[MJ]

7110.65 ch3, ch7; AIM ch 3-2; 14 CFR Subpart B
probably others...

 

[rhombus]

I believe you from a common-sense and "everyone does it this way" standpoint. I'm not about to go to work and launch a VFR Twin Cessna with 2000-and-airborne behind a Skyhawk. Obviously.

But do you have a textual reference for that statement? 7110.65, 7210.3, ICAO PANS-ATM, anything?

Runways are part of the earth and are not considered or included in airspace


“from the surface” not “including the surface”

 

[Somenewguy]

If you consider runways airspace would you also consider taxiways airspace? How would you go about applying Class B or Class C airspace separation to two taxiing aircraft?

I didn't say runways are airspace. I said your explanation of how things are doesn't make sense because same runway separation DOES include airborne aircraft.

 

[Somenewguy]

If a departing aircraft is airborne 1500 feet from the arrival threshold and a landing aircraft crosses the runway threshold, both aircraft are in the airspace and runway separation still applies. Your explanation of why runway separation is independent of airspace designation isn't sound.

Runways are part of the earth and are not considered or included in airspace
View attachment 8629

“from the surface” not “including the surface”

 

[rhombus]

From

/frəm/
preposition
1.
indicating the point in space at which a journey, motion, or action starts.
"she began to walk away from him"
2.
indicating the point in time at which a particular process, event, or activity starts.
"the show will run from 10 to 2"

Thanks for the grammar lesson. Look at the part I highlighted. “Airspace from the surface”. The surface is not considered part of airspace. If you control traffic on the surface based on airspace separation standards, good luck to you and whatever airport you work at

 

[LikeLemon]

If they are in the pattern, and can't get pilot applied, it's time for them to full stop.

I've full stopped people for less...

 

[exercisefaith]

Somebody clear this up for me. (Class D airspace). A large and a small doing patterns to the same runway.

A large aircraft is doing patterns and is on the go. A skyhawk is also doing patterns and turns base to follow the large. My OJTI said I need to start the 3 min timer when the large rotates off the runway to provide wake turb sep for the VFR skyhawk because he is an intersection departure when he does his touch and go or get the large in sight for the skyhawk. At my last facility I just issued a cautionary to the skyhawk. Is my OJTI correct in requiring the 3min/visual or do I just need the cautionary?

 

[HammerHead]

No, that's IFR separation. The separation between an A388 super arrival and a C172 doing pattern work is don't trade paint and a cautionary wake turbulence advisory.

I understand that it's in the radar separation section which is synonymous with IFR but wake turbulence affects everyone. You make a good point.

It doesn't make sense to me to have wake turbulence separation by minutes for departing VFR aircraft but on final it doesn't matter let them get blown away.

My question to you is, do you provide that separation between IFR aircraft or TO an IFR aircraft. Example, you have a IFR small on an instrument approach. Tower has a heavy in the pattern. They base their VFR heavy in front of your IFR small. Do you need to apply 6 miles of separation or does it not matter because the heavy is VFR?