VFR Radar Operations

[Cristóbal Catalán]

I've been studying the Seattle area documents and other pieces of relevant information for the process of checking out for Seattle Tower and a few questions have come up the back of my mind. SOP 003 states the following:

iii. Certain towers will be given authority to use radar procedures to separate traffic; All Class C and B Towers are assumed to have radar, if a Class D airport is assumed to have radar it will be stated in SOP_100. At those towers where authority to use radar separation is not given in SOP_100, tower controllers will be responsible for providing traffic separation using non-radar or visual separation methods.

Paying attention to the section regarding Class C airports, it mentions that Class C airports are equipped with a radar display.

The Seattle Class B VFR Transition example records SEA_TWR radar identifying a target 10 miles west of the Seattle Tacoma airport and issuing a point-out for the S46 controller above him before giving the aircraft instructions to transition the Class D airspace and telling him he's on radar contact.

In a hypothetical scenario, wouldn't the same situation apply to Portland? Wouldn't PDX_TWR be able to radar identify and radar contact aircraft wishing to transition the Portland Class C? In practice, this doesn't happen at all (at least in my case) and for the few class C transitions that I've handled, I have only verified radar altitude by asking the transitioning aircraft to say altitude as instructed in the VFR Aircraft Phraseology ARTCC document. Note the document also allows the tower to give 'suggested headings' where needed to avoid traffic or for navigational purposes. This leads one to believe that the Portland tower radar display is a certified display workstation.

Transitioning from ARTCC to FAA documents, the 7110.65X notes this in section 3-1-9. USAGE OF TOWER RADAR DISPLAYS.

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.”

Usually when handling a VFR departing/transitioning aircraft from Portland it feels like I'm missing something after confirming the data block's altitude with the PIC and before handing them off to P80/UNICOM and this may be what I think it is.

I guess the real thing I'm wondering is if Portland falls into the 'unauthorized' category that isn't able to radar contact aircraft while Seattle Tower falls into the 'authorized' category or if I'm wrong and Portland is authorized to radar contact arriving/transitioning/departing VFR aircraft. I'm leaning more towards the 'unauthorized' part, since we are not taught any of the mentioned procedures in Minor Tower training.

[Frank Miller]

Cristobal, Great questions. I think the lack of "radar services" on VATSIM is more a function of the network than an attempt to mirror real world procedures. A tower with certified radar (both equipment and personnel!) would "radar contact" both VFR arrivals and departures and provide radar services to them as per the 7110.65 and AIM. This might include transitions, as you say. It would certainly include separation services and vectoring.

I suspect, however, that VATSIM is ill-suited to this approach. First, the training for S2 (Tower) is rather heavy on the fundamentals of tower operations and an additional topic on radar services would be of little practical value given the predominance of IFR traffic on the network. Second, in a sense we are all using radar anyway----we don't have "visual" methods available to us (save, of course, for the luck few who can link up to a sim and create a "tower view"!). And the model matching and potentially incongruous weather being applied by different pilots means we would struggle to truly make a distinction between "visual" and "radar" identification. I suspect this all combines to make VFR radar services just one step too far in terms of applicability to VATSIM. The fact we have charted VFR transitions in the Seattle Class Bravo does afford us a discrete opportunity to teach and apply radar services albeit in a very limited context----but this doesn't meant those services aren't applicable in other cases in both Class B and C airspace.

As for uncertified radar services---that's pretty much VATSIM anyway! I know at my local RW tower (KSGJ, Class D) they use radar to assist in VFR operations, locating aircraft in relation to the field, providing traffic callouts, and maintaining situational awareness more generally. When I got a tower cab tour it was very reassuring and familiar to look at their radar display. It pretty much looked just like VRC.

Frank