vertical separation for traffic alert?

[GeorgeC]

On the way home on Monday, I had traffic 1000' directly below me, same location, same direction of flight. I saw them on ADS-B, but Tracon didn't mention them. Eventually our paths diverged and I saw them scoot away. How close would we have needed to be vertically before we received an alert?

 

[RyanB]

Funny you mention that, because a similar situation happened to me on Sunday*.

Had just been terminated by TRACON, squawked 1200 and changed over to CTAF. Just after my initial radio call, I look up and see an RJ 1000ft above me, opposite direction. Was quite surprised that ATC never queued me on them.

*I was not ADSB equipped, so it’s not the same situation.

 

[AggieMike88]

Monday as I was headed southbound over Fort Worth and above the clouds at 5000 feet MSL, I was advised of a jet flying the opposite direction at 4000 feet and very much obscured by the cloud deck.

I said thanks to the controller, and said I would not be able to see him at all due to the clouds.

Controller responded, "yeah, I thought so, but since you two are at 1000 feet separation, I'm required to advise you of each other." Totally professional in his tone and I appreciated his explanation.

 

[Timbeck2]

On the way home on Monday, I had traffic 1000' directly below me, same location, same direction of flight. I saw them on ADS-B, but Tracon didn't mention them. Eventually our paths diverged and I saw them scoot away. How close would we have needed to be vertically before we received an alert?

Were you both VFR? 500'
1000' for IFR unless you were in the flight levels which I doubt.

 

[GeorgeC]

Were you both VFR? 500'

Yep, both VFR. Thanks!

 

[Timbeck2]

Welcome

 

[asicer]

Were you both VFR? 500'
1000' for IFR unless you were in the flight levels which I doubt.

Interesting. I was Northwest bound at 8500 in a WAAS G1000 DA40 on an airway with the GFC700 autopilot flying and was given a traffic alert for another DA40 (likely similarly equipped and also on the airway) in the opposite direction.

This was a couple years ago but the reason I still remember it because I was thinking I could probably just look at the spinner and tilt my head up a few degrees to spot it. Sure enough, he passed directly over my centerline and I directly under his. Amazing how accurate is WAAS and digital autopilots.

Maybe the controller was bored.

 

[Velocity173]

Technically it’s not an”alert” just a “traffic advisory.” Alert-unsafe proximity. Traffic advisory-given when separation may decrease to less than minimum, or where no sep exists, controller’s judgment.

Aggie got the advisory because the controller was providing “merging target procedures” for the turbojet.

Sep standards are as Tim stated above...if you were in airspace that requires sep for VFR aircraft.

 

[luvflyin]

On the way home on Monday, I had traffic 1000' directly below me, same location, same direction of flight. I saw them on ADS-B, but Tracon didn't mention them. Eventually our paths diverged and I saw them scoot away. How close would we have needed to be vertically before we received an alert?

Pretty much just the controllers judgment if they think it's warranted.

2−1−21. TRAFFIC ADVISORIES
Unless an aircraft is operating within Class A airspace
or omission is requested by the pilot, issue traffic
advisories to all aircraft (IFR or VFR) on your
frequency when, in your judgment, their proximity
may diminish to less than the applicable separation
minima. Where no separation minima applies, such
as for VFR aircraft outside of Class B/Class C
airspace, or a TRSA, issue traffic advisories to those
aircraft on your frequency when in your judgment
their proximity warrants it. Provide this service as
follows:
it goes on with all clock position phraseology stuff. That's just calling traffic. If by 'Alert' you mean an actual Safety Alert it's this

2−1−6. SAFETY ALERT
Issue a safety alert to an aircraft if you are aware the
aircraft is in a position/altitude that, in your judgment,
places it in unsafe proximity to terrain, obstructions,
or other aircraft. Once the pilot informs you action is
being taken to resolve the situation, you may
discontinue the issuance of further alerts. Do not
assume that because someone else has responsibility
for the aircraft that the unsafe situation has been
observed and the safety alert issued; inform the
appropriate controller.
b. Aircraft Conflict/Mode C Intruder Alert.
Immediately issue/initiate an alert to an aircraft if you
are aware of another aircraft at an altitude that you
believe places them in unsafe proximity. If feasible,
offer the pilot an alternate course of action. When an
alternate course of action is given, end the
transmission with the word “immediately.”

As far as what altitudes constitute less than applicable separation minima it varies depending on the Airspace you are in. Pretty much what @Timbeck2 said above, 500 VFR and 1000 IFR. In your example, 1000 feet and not looking like it might be decreasing shouldn't give the controller a reason, but often they call it anyway.

 

[asicer]

Ah, so it was a bored controller, then...

 

[luvflyin]

Technically it’s not an”alert” just a “traffic advisory.” Alert-unsafe proximity. Traffic advisory-given when separation may decrease to less than minimum, or where no sep exists, controller’s judgment.

Aggie got the advisory because the controller was providing “merging target procedures” for the turbojet.

Sep standards are as Tim stated above...if you were in airspace that requires sep for VFR aircraft.

Yup. Here's what that is about:

5−1−8. MERGING TARGET PROCEDURES
a. Except while they are established in a holding
pattern, apply merging target procedures to all radar
identified:
1. Aircraft at 10,000 feet and above.
2. Turbojet aircraft regardless of altitude.
REFERENCE−
P/CG Term− Turbojet Aircraft.
3. Presidential aircraft regardless of altitude.
b. Issue traffic information to those aircraft listed
in subpara a whose targets appear likely to merge
unless the aircraft are separated by more than the
appropriate vertical separation minima.

 

[luvflyin]

Ah, so it was a bored controller, then...

Some just like to hear themselves talk more than others. Actually I don't mean that quite as harsh as it sounds. In my experience more often than not the 1000 foot traffic call gets made. Just makin sure y'all aint gonna think we fell asleep or had a heart attack or sumpin.

 

[Timbeck2]

Controllers are sometimes damned if they do and damned if they don't. Several years ago, I had a small business jet fly over our runway (12/30) in route to land runway 21 at Tucson with a flight of four A-10s at initial (yep, there's that word again) with 700 feet vertical separation. The SOF* (Supervisor of Flying, NOT supervisor of controlling...that's MY job) jumped up and demanded my local controller give traffic to the A-10s. I calmly told the SOF that my controller wasn't going to do that and that he needs to keep his outbursts toward something that is more important. I also explained that we only needed five hundred feet and we had two hundred over the minimum. He countered with "where do you think number four (the fourth A-10 in the flight) is looking?" I replied, " I don't care where the A-10 pilot is looking, I only care that my controllers follow the rules - which they are."

This happened a few years ago and long after I took off my uniform, I would be a lot more tactful had I still been in uniform. It's good to be a civilian.

* The SOF is a rated A-10 pilot who is up in the tower to help the single seat A-10 pilot in case of emergency and also is our go-between to the operations group commander if we need approval for things such as heavy departures that will go over the city. A SOF in no way directs air traffic and most of them are great guys/gals and easy to work with. This one on that day wasn't.

 

[FlySince9]

dam, thats a creepy avatar...

 

[AggieMike88]

Were you both VFR? 500'
1000' for IFR unless you were in the flight levels which I doubt.

Both IFR.

Me, headed "out of town" through the DFW bravo and had recently climbed through the layer.

Him, I think he was headed toward Meacham.

 

[Velocity173]

Controllers are sometimes damned if they do and damned if they don't. Several years ago, I had a small business jet fly over our runway (12/30) in route to land runway 21 at Tucson with a flight of four A-10s at initial (yep, there's that word again) with 700 feet vertical separation. The SOF* (Supervisor of Flying, NOT supervisor of controlling...that's MY job) jumped up and demanded my local controller give traffic to the A-10s. I calmly told the SOF that my controller wasn't going to do that and that he needs to keep his outbursts toward something that is more important. I also explained that we only needed five hundred feet and we had two hundred over the minimum. He countered with "where do you think number four (the fourth A-10 in the flight) is looking?" I replied, " I don't care where the A-10 pilot is looking, I only care that my controllers follow the rules - which they are."

This happened a few years ago and long after I took off my uniform, I would be a lot more tactful had I still been in uniform. It's good to be a civilian.

* The SOF is a rated A-10 pilot who is up in the tower to help the single seat A-10 pilot in case of emergency and also is our go-between to the operations group commander if we need approval for things such as heavy departures that will go over the city. A SOF in no way directs air traffic and most of them are great guys/gals and easy to work with. This one on that day wasn't.

SOF kinda sounds like a position that would be a PITA in the tower. Air Ops O used to come up to the tower and chit chat with us but he had no authority on any ATC procedures.

I think if the business jet was restricted to at least 500 ft above the A-10s, I wouldn’t call traffic. A lot of the controllers these days are just traffic call crazy and want to hear themselves talk. They’ll even throw in a “should be no factor” at the end of it. Well if that’s the case, why even bother with the call. Bunch of Ms!