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Class D arrival WT

Discussion in '7110.65' started by MJ, Jun 10, 2017.

  1. MJ

    MJ Administrator Staff Member

    In a class D tower, is radar wake turbulence separation applicable between a larger VFR a/c followed by a smaller IFR a/c on final?
    Why or why not.

    the short answer is aircraft would not receive radar separation from the VFR tower, in accordance with 5-5-4. Chapter 5 is radar separation and VFR tower controllers are normally not operating under Chapter 5, Radar. However, wake turbulence procedures still apply in accordance with 2-2-19&20 and 3-10-3, which are advisory in nature. The inbound IFR would receive the approach clearance from radar approach control and communication would be transferred to the tower (typically, at least 7 to 10 miles out). Radar Approach may not even know what type aircraft is in the VFR pattern. Either way, the requirement would be for the tower to ensure Wake Turbulence advisories with the VFR aircraft.
    Last edited: Mar 13, 2018 at 5:51 AM
  2. cosoccer

    cosoccer Certified FAA

    FAA Facility:
    MDT Harrisburg Tower
    Oh geez, this has been a lengthy debate here at our up/down. I don't even know what is right anymore...
  3. ATOH

    ATOH Certified

    I don't work in a class D tower so I could very well be wrong but I would think so because just because larger a/c is VFR doesn't mean he doesn't cause wake turbulence. I would try hard to get the smaller a/c to report the larger one in sight though.

    How many VFR Gulfstream's can there be flying around anyway?
  4. cosoccer

    cosoccer Certified FAA

    FAA Facility:
    MDT Harrisburg Tower
    We have Military and presidential fleet practice up frequently mixed with smalls and majority believe it does not apply because tower does not apply radar separation. Even though an up/down might know what traffic is in the pattern, you will not as radar, know what's at a satellite/contract "D" so how can you apply it?
  5. rhombus

    rhombus Developmental

    7110.65 3-10-3 b., 2: Issue wake turbulence advisories, and the position, altitude if known, and the direction of flight of: The B757/large aircraft to a small aircraft landing behind a departing/arriving B757/large aircraft on the same or parallel runways separated by less than 2,500 feet.

    It's just an advisory. We sequence the small behind the large just like any other aircraft, give the advisory, and clear them. More often than not the pilot of the small will extend their downwind to allow extra spacing behind the large, understandably.
    ajmezz likes this.
  6. echster

    echster Certified

    My two cents.

    Responsibilities for ensuring separation in instances like this are normally addressed in LOAs or facility directives; however, if they are not, the answer depends on specifics.

    Yes. See .65, 5-9-5. Tower has a responsibility to the appropriate radar facility (ARTCC, TRACON, or Tower controller authorized to perform approach services) for maintaining radar wake turbulence separation for aircraft cleared for IFR approaches. For example, a radar facility (one of the three listed above) clears a C-172 for an ILS approach and Tower has a large in the VFR pattern. In this instance, the Tower cannot jam the large in front of the C-172 because the IFR aircraft receives separation services (radar and radar wake turbulence) when cleared for an approach. Tower-applied visual separation is not applicable in this instance because .65, 7-2-1.a.1.(e) states, "The use of tower-applied visual separation is not authorized when wake turbulence separation is required."

    No. The IFR small aircraft was cleared for a visual approach and visual separation is being used. For example, the same C-172 above requested a visual approach and the Tower coordinated with the radar facility something like, "The C-172 is number 2 to follow the Super King Air turning base." The radar facility issues the traffic, the C-172 sees the traffic, and is then cleared to follow the traffic for the visual approach. In this instance, a wake turbulence advisory need only be issued vice maintaining radar wake turbulence separation.

    Here is a decent guide to wake turbulence separation. Responsibilities are in 2.6. (ATC) and 2.7. (Pilot).
  7. eltors0

    eltors0 Chow Runner FAA

    FAA Facility:
    MFD Mansfield Tower
    No. You are responsible for the applicable time based wake turbulence minima as stated within chapter 3 sections 9 and 10 of the .65.
    MJ likes this.
  8. CaptainObvious

    CaptainObvious Certified

    My take is also this. The transition is made from the radar to tower environment and becomes a time based arrival WT sep. it functions the same way as maintaining IFR separation in the class delta. Have to have sep until Tower can maintain visual, have to have WT sep until Tower can apply WT time.

    Just my take though.
  9. rugbydog11

    rugbydog11 Certified

    I always air on the side of safety, especially in the world of wake turbulence. If radar needs miles, I do not put a large or heavy in front. I can see the argument either way, but which way would you rather argue in court when the light sport flips and dies because you short approached a C17?
  10. wikdevo

    wikdevo Certified

    is the smaller ac being radar vectored ?
  11. rhombus

    rhombus Developmental

    I get the point you're trying to make, but there is no wake turbulence separation between a small landing behind a large on final. It doesn't matter if it's IFR/VFR, VFR/IFR, VFR/VFR, or IFR/IFR. It's just an advisory. 7110.65 3-10-3 Section b, Paragraph 2.

    Now is it a good idea to force an RJ's base in front of a Cessna on a four mile final? Of course not. But as long as you give the wake turbulence advisory, it is legal.
  12. ATOH

    ATOH Certified

    You sure about that.....? I sure hope the small has the large in sight. Especially if both are IFR
    wikdevo likes this.
  13. CaptainObvious

    CaptainObvious Certified

    Why? Small to large is for arrival after a departure.
  14. rugbydog11

    rugbydog11 Certified

    Ummmmm.... 3 increasing to 4 at the threshold. If the threshold can't be determined, the furthest point that can? If tower can't provide visual with a small behind a large both IFR why would they be able to tuck a vfr large in front. Still the same amount of wake turbulence.
    wikdevo likes this.
  15. rugbydog11

    rugbydog11 Certified

    7-2-1 e, 5-5-4 h,
  16. CaptainObvious

    CaptainObvious Certified

    3 increasing to 4? That's a new one to me. I see what you're referencing but 3 miles is a wake turbulence bust to start. using 5 to get 4 at the threshold, 6 to get 5 etc, is a much better way of saying what you're trying to say. With the VFR arrival in front, it is the same amount of wake turbulence, but all you're required to give is a cautionary for a small arrival behind a large arrival to the same runway. Page 3-10-3.
    Last edited: Jun 10, 2017
    #1349 likes this.
  17. Robertb

    Robertb Certified FAA

    FAA Facility:
    A80 Atlanta Tracon
    Is the tower radar certified and responsible for providing radar separation to aircraft?
    rhombus likes this.
  18. rugbydog11

    rugbydog11 Certified

    Standard 3 small behind a large... It becomes 4 once operating directly behind on an approach and the 4 must exist by the time the first aircraft (large) crosses landing threshold.
    wikdevo and GulfBravoPapa like this.
  19. Stinger

    Stinger Certified

    Using 5 to get 4? How does that work with a C172 following a B737?
    It's 3 miles, increasing to at least 4 miles when the B737 crosses the threshold.
    wikdevo, rugbydog11 and corn4ahead like this.
  20. Stinger

    Stinger Certified

    This is what I'd go with.

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