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?

 

[rhombus]

This argument doesnt really hold up to scrutiny.

If you're 2000' from the runway threshold and airborne in a class delta, you are no longer on the surface, so I can land a 747 behind that Cessna right?

Or to put it another way, a landing aircraft can cross the runway threshold with another aircraft on the runway but as long as it's airborne I don't have to apply any separation?


Everyone claims the 7110 was written by lawyers but it was mostly written by a bunch of FAA management/staff support types who "fixed" problems haphazardly as they arose. It is written with the assumption that the person reading it can infer quite a bit of the practical application aspect and avoid using rules in situations where it would compromise safety. Unfortunately most people are kind of stupid so they find new ways to fuck things up while still thinking that theyre following the rules. As a consequence the rule book has to get bigger every year because it doesn't explicitly say what to do in every situation.

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?

 

[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.

 

[rhombus]

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.

All runway separation is based on markings or landmarks on the ground. The ground is the reference point. It doesn’t matter if one of the aircraft involved is airborne. Runway separation or lack thereof occurs on the ground

 

[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”

 

[AlphaLima@]

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

“from the surface” not “including the surface”

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"

 

[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?

 

[Phanatical]

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?

As long as the 172 gets the large in sight, you can instruct the Skyhawk “Maintain visual separation, caution wake turbulence.” After that you don’t need the timer. It’s not strictly a cautionary since you are instructing to maintain visual (7110.65 3-9-7-b-3)

 

[sizziano]

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?

3 mins or visual as Phanatical said