Wake Turbulence Advisories

[Rob Law]

I was talking with one of our fellow controllers (who will remain nameless) last night about the excellent approach control displayed by Keith last night.

Here is the setup, the two a/c on the simutaneous parallel apps was a 737 in the lead followed by a 757. The controller in question was also listening in to my comms (for what reason I dont know :lol: ) and asked my why I didn't issue a wake turbulence advisory to the 757 following behind the 737.

I said to my knowledge wake advisories are issued when the smaller a/c is behind the larger one and that a 737 whould hardly disturb a 757. His contention was that because of the close proximity of the two, an advisory should have been issued.

Well buddy I actually looked this up in the bible and you owe me 15 cents :P . Here is the text:

2-1-19. WAKE TURBULENCE

a. Apply wake turbulence procedures to aircraft operating behind heavy jets/B757's and, where indicated, to small aircraft behind large aircraft.

NOTE-
Para 5-5-4, Minima, specifies increased radar separation for small type aircraft landing behind large, heavy, or B757 aircraft because of the possible effects of wake turbulence.

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

REFERENCE-
FAAO 7110.65, Approach Separation Responsibility, Para 5-9-5

2-1-20. WAKE TURBULENCE CAUTIONARY ADVISORIES

a. Issue wake turbulence cautionary advisories and the position, altitude if known, and direction of flight of the heavy jet or B757 to:

REFERENCE-
AC 90-23, Aircraft Wake Turbulence, Pilot Responsibility, Para 12.

1. TERMINAL. VFR aircraft not being radar vectored but are behind heavy jets or B757's.

2. IFR aircraft that accept a visual approach or visual separation.


This is naturally a moot point on vatsim because wake turbulence isnt simulated in FS.

[TONY]

:o Ok Lets raise the 15 cents to 20 cents shall we...

When you have landing traffic at an airport with parellel approacehes, like sfo..

Scenario

The winds, lets say 200 at 5 k-10 kts, landing runways 28l and 28r are in effect. Little b737 lands 28l first followed by big brother 757 lands 28r,

Is this a case to issue caution wake turbulence alert? In prepartion to landing.

What are those little crazy vortices doing in a gentel breeze? Perhaps moving towards the north east (28r) might be in the way?

I have never known of an aircraft that has not been disturbed by those little crazy vorticies????

[Rob Law]

Hey man 20 cents it is :D , notice I was trying to keep your identity secret.

My answer is still no because the 737 will do nothing to the 757. now if a cessna was in trail of the 737 I would.

OK now its time for one of you real smart vatsim people to join in.

Rob

[Dan Sprouse]

here is what is in the VATUSA Training Material for TOWER

6-4-1. Apply wake turbulence procedures to aircraft operating behind Heavy jets and, where indicated, to Small aircraft behind Large aircraft. Specific separations are listed in the appropriate chapters.

6-4-2. Separation shall continue to touchdown for all IFR aircraft not making a visual approach or maintaining visual separation. (NOTE this paragraph states that only seperation will be maintained for all IFR TRAFFIC until touchdown) It does not say anything about wake turblance notice. That is covered in the following paragraph.

6-5. Issue wake turbulence cautionary advisories, eg "CAUTION WAKE TURBULENCE" to:

6-5-1. VFR aircraft behind a Heavy or B757.

6-5-2. IFR aircraft that accept a visual approach or visual separation behind a Heavy or B757.

6-5-3. Any aircraft if in your opinion wake turbulence may have an adverse effect on it.

The above information is taken from the VATUSA Training Material which is stating what the FAA 7710.65 REGULATIONS SAY.

I have to agree with Rob on this one the need to issue a wake turblance is not needed for a 757 following a 737.

[Inigo Markle-Allen]

If you have simultanious visual approaches coming into 28L and 28R side by side (this is legal so long as they don't overtake each other) then the 737 is going to have an adverse effect on the 757 no matter how much heavier it is. There's still going to be turbulence coming off the vorticies of the wings, and that's where:

"6-5-3. Any aircraft if in your opinion wake turbulence may have an adverse effect on it."

Comes into play. When you have large airlines within a mile or two there's no question there's going to be wake turbulence, regardless of the size of the airplane. By cautioning the pilot you let them decide what to do with their "Visual seperation" clearance if they're going to be coming in simultaniously. It's really common to hear Norcal set a BSR2 on the TIP TOE 28L, and send a MOD2 heading to intercept the SFO 095 radial. Let's say the BSR2 is an A320, the MOD 2 might be a 767. Approach might go "Follow the 737, caution wake turbulence, he's for 28 LEFT, cleared visual approach 28 RIGHT." This would be within a mile or so though, so they'd have to be visual sep or it'd be a deal anyway. You also hear stuff like "Do not overtake the airbus" because that's another wake turbulence rule (Do not allow a large aircraft to overtake a small aircraft, heavy/757 to overtake a large aircraft). So what am I getting at? Wake turbulence rules are increadibly specific, so much so that controllers don't have time to know exactly when to issue the advisory and do it when two planes get close, regardless of how much they weigh I generally hear controllers just say it for the hell of it so they're not responsible should something happen and legal action be taken (obviously if it was a 737 behind a cessna it'd be a little different, although I've heard controllers at large airports slide a caution wake turbulence in there as a joke when ever they can (also "Check gear" on a fixed gear airplane)). Inigo's stance on the issue: Depends how far behind he was Tony. If they were parallel, go for it. If he was more than 3 miles in trail, that's legal and not a factor. Use your best judgment, although I've never heard of five knot winds overtaking an airplane with an approach speed in excess of 140. :huh:

EDIT: 737s depart 1L and 1R side by side a lot (check airliners.net keyword "simultanious or parallel) and still get wake turbulence advisories. After all, they're right next to each other, in an airplane that rocks around from thermal lift from parking lots, you'd think some wing tornados (yes I know... vorticies :P ) might be somewhat of a factor...

[bradl]

To add onto this (and a really cool trick to do with parallel approaches; we do this at KLAS when the 1s are in use) is to get them wing to wing from the approach all the way down.

As long as the 757 does not pass the 737, they can get wing to wing all the way down. I've seen two SWA 737s accomplish this together; one Silver One, the other Shamu One. This also has happened with a Twin Cessna and a 737, but once again, as long as the larger of the two aircraft does not overtake the smaller one, getting wing to wing is perfectly legal.

There is a picture on airliners.net of a Lear 45 and a 744 landing simultaneously, nose to nose, at KLAX. I can't remember which airline the 744 was (might have been JAL), but do a search there for simultaneous approaches, and it should pop up.

BL.

[Sachin]

here is that picture

http://www.airliners.net/open.file/509635/L/

[Inigo Markle-Allen]

For you SFO lovers out there...

Simultanious side by side arrivals to 28L and 28R:

http://www.airliners.net/open.file/486967/L/

http://www.airliners.net/open.file/342514/L/

http://www.airliners.net/open.file/414843/L/

http://www.airliners.net/open.file/475430/L/ <- That&#39;s what I call cutting it CLOSE&#33;

The side by side 1L and 1R takeoffs I was talking about:

http://www.airliners.net/open.file/019164/L/

http://www.airliners.net/open.file/481622/L/

^ How can they get away with this? 1L departure on the PORTE3 turns left heading 350. 1R departure on the SFO8 turns right heading 030. B) Like so (look really hard in the backround):

http://www.airliners.net/open.file/310063/L/

And of course all of that ILLEGAL overtaking that&#39;s not SUPPOSED to happen:

#1 - http://www.airliners.net/open.file/176899/L/

#2 - http://www.airliners.net/open.file/176898/L/

Now is SFO not the freakin coolest airport in the world? B)

[bradl]

There&#39;s actually one more that I&#39;m looking for, that has a Gen Av jet nose to nose with a B744 (can&#39;t remember the airline) and I want to say it&#39;s at KLAX..

But here&#39;s a good example:

http://www.airliners.net/open.file/025792/M/

as long as the B777 doesn&#39;t pass the B735, you&#39;re good to go. Just remember:

give wake turbulence caution to:

smalls behind larges
smalls behind heavies or B757s
Large behind Heavies/B757s
Heavies behind Heavies/B757s.

Do a google search for In-n-Out Burger, and try to find something on the founder. You will find out that he was actually killed in an airplane accident in his prop, because he was intrail of a B757, and was caught in its wake. Because of that accident, the whole Wake Turbulence concept came into existence.

BL.

[feathers]

Originally posted by Dan Sprouse@Feb 15 2004, 09:52 PM
6-5. Issue wake turbulence cautionary advisories, eg "CAUTION WAKE TURBULENCE" to:

6-5-1. VFR aircraft behind a Heavy or B757.

6-5-2. IFR aircraft that accept a visual approach or visual separation behind a Heavy or B757.

6-5-3. Any aircraft if in your opinion wake turbulence may have an adverse effect on it.
Love that crazy FAA... as Inigo says, they give you a very specific list of when to issue clearances, and then say "Any aircraft in your opinion..."

I guess it allows you (as a controller) to cover yourself, but so much for the specific rules. &#39;This, this, this and this and then anything else you think needs it...&#39;

^_^

James

[Shane]

Originally posted by inigo88@Feb 16 2004, 06:58 PM
http://www.airliners.net/open.file/475430/L/ <- That&#39;s what I call cutting it CLOSE&#33;

Now is SFO not the freakin coolest airport in the world? B)
I would call it 750ft close-- especially if you&#39;ve got 2 B777s landing in parallel.

As for wake turbulence at SFO I&#39;ve sat out an listened to ATC and haven&#39;t heard many wake turbulence advisories on parallel approaches to the the 28s. I do hear a lot given by SFO TWR because of cross traffic of the departures on the 1s and arrivals on the 28s

SFO is a cool airport except when you have weather. I&#39;ve spent many hours in a holding pattern or sitting on the ground because of flow control into KSFO because of fog, wind, rain etc... That&#39;s the problem with insufficient runway separation at KSFO--landing capacity is restricted 50% when visibility falls. That&#39;s why they&#39;re pushing hard to reconfigure runways for 1/4 mile separation. The sticking point is how much they have to fill in the San Francisco Bay to do it.

[feathers]

Originally posted by Shane@Feb 18 2004, 09:20 AM
visibility falls. That&#39;s why they&#39;re pushing hard to reconfigure runways for 1/4 mile separation. The sticking point is how much they have to fill in the San Francisco Bay to do it.
What&#39;s this? Are they abandoning the construction of the PAR system? Or do they want something that will be operational sooner?

James

[Scott Fritz]

From what I understand the PAR system will only increase capacity by around 30%. Seperating the runways would gain them more capacity than the PAR can. I believe the PAR should be online this spring at KSFO.

[bradl]

Thanks to Mike Hale down at ZLA, I was able to find the picture in question of simultaneous approaches. It&#39;s of a JAL B744 for 25R, and a Gulfstream for 25L. As long as the 744 doesn&#39;t pass the Gulfstream, they can land at the exact same time. The 644 can slow up, get wing to wing, or nose to nose, but just can not pass him. otherwise, wake turbulence advisories and slowing the Gulfstream down would come into play, and make for a serious issue, especially that close to touchdown. But enjoy&#33; :)

JAL B744 and Gulfstream at KLAX (http://www.airliners.net/open.file/150311/L/)

BL.