TACAN Point to Point

Discussion in 'Flight Following' started by midlifeflyer, Sep 23, 2020.

  1. Bob Noel

    Bob Noel Touchdown! Greaser!

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    yup

    I was always making that typo way back when...
     
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  2. 35 AoA

    35 AoA Pattern Altitude

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    Not only this, but until fairly recently, the entire F/A-18 fleet was TACAN only with no (shore based) ILS.....so PAR/ASR or TACAN approach only. We do have RNAV now, but without vertical guidance, so we can only use LNAV MDA. Granted we have had an INS for as long as the jet has existed, so you could manually enter coordinates for a waypoint/navaid/airfield if you happened to have them.
     
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  3. Boone

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    Same with F-14, no named waypoints and no normal ILS. I assume the F-5’s still have to file /T, and the T-38A’s.
     
  4. Pugs

    Pugs Line Up and Wait PoA Supporter

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    We got civilian ILS in the Prowler in the block 89 so about 2000. It came from money the USAF (with the demise of the EF-111) gave the Navy since the expeditionary shore based squadrons needed them as we were flying out of a lot of USAF and overseas bases with no GCA so it was our only precision approach. Same mod got us the GPS so were used that for PtP to fixes.

    I do not remember TACAN point to points fondly in the T-2 in the winter at altitude with a 100+ kts of cross wind.:(
     
    Last edited: Sep 24, 2020
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  5. midlifeflyer

    midlifeflyer Touchdown! Greaser!

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    Yes.
     
  6. midlifeflyer

    midlifeflyer Touchdown! Greaser!

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    That's interesting. Suggest why there was a letter if there was one.
     
  7. midlifeflyer

    midlifeflyer Touchdown! Greaser!

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  8. Boone

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    If you’re getting that from 4.13, that’s referencing PBN. I think that is only referring to accepting RNAV fixes. There’s nothing I’ve seen in the other chapters to suggest that when navigating by ground based stations, you can’t accept direct to a fix. But with the Air Force, anything goes. You may be correct, but that’s not how I would interpret it based on 202v3z
     
  9. MauleSkinner

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    If the Bellamy Brothers covered that song, would it be about “Bellamy Drift”?

    (you can use your CR-3 to calculate that, too.)
     
    Last edited: Sep 23, 2020
  10. Sluggo63

    Sluggo63 Cleared for Takeoff

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    Let’s just say there were pretty strong feelings on both sides when the Fix-to-Fix procedure went away...

     
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  11. luvflyin

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    How do you use the non normal ILS. I assume you mean ICLS. I’ve never seen a published ICLS Approach and never a line of minimums on a TACAN Approach that mentions it. Can you reduce the Straight In minimum if you have it?
     
  12. Boone

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    If I remember right, there were only a handful of non-carrier ICLS approaches when I was flying. Oceana had one, I think. But I don’t remember ever pulling one up on a plate and doing one on the shore. It was supposed to be the same equipment as the ship with a pre-assigned code selected in the cockpit that allowed you to pick 1-20. PARs were more common.
     
  13. luvflyin

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    Well I’ll be dipped. There is such a thang. So you could be cleared to wherever via 29.92 30.03 30.11 direct
     
  14. hindsight2020

    hindsight2020 Final Approach

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    On the USAF side, "fix-to-fix" (what this thread is calling point to point) was officially excised from the undergraduate syllabus and MWS form 8 instrument qual evaluations circa 2013-14. For those unfamiliar, as @Sluggo63 already described in post 37, the procedure is essentially applying dead reckoning and trigonometry approximations to whip out a wind corrected heading out of your @ss in order to emulate going direct to a fix defined by a radial and DME on that radial, while having that radial dialed into your HSI/CDI, and where no course deviation indication direct to said target position is otherwise available to ya on the RNAV equipment front.
    upload_2020-9-23_19-52-7.png
    Essentially, manually computing and updating a track by the use of an RMI (bearing pointer) and a target DME on a radial you're not on yet. Essentially mimicking a "direct to" like what an RNAV equipment provides you. Suffice to say, most people sucked at it and the errors would frequently **** off controllers.

    With the advent of GPS equipment proliferation, the technique was evaluated to be unnecessary (the back and forth regarding the merits of such an adjudication is of course the genesis of many of the videos like the one @Sluggo63 posted on #50) and at least from my recollection as a line instructor, the FAA had a hand in forcing that operational exclusion while in the NAS. A "letter" from the FAA of course wasn't furnished to us as part of the airman read file (FCIF, in USAF parlance), and frankly I'm more interested in why the OP is being so cryptic about his interest in the existence or non-existence of such a "letter".

    BL, there's no conspiracy here, nor is it a secret the DOD got rid of fix-to-fix operations in their Service Components' instrument manuals/instructions/et al. We're not bounded by the FARs per se, but we are guests in the NAS, and the FAA rightfully controls it. Getting rid of fix to fix ops in the NAS was imo part of that stewardship and goodwill, ditto for ADSB-out equipage in selected MDS's.
     
    Last edited: Sep 23, 2020
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  15. N1120A

    N1120A Pattern Altitude

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    CZQ
     
  16. 35 AoA

    35 AoA Pattern Altitude

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    You use it at the ship; it looks and flies like any normal ILS, though the pilot inputs a channel rather than a frequency. Like Boone mentioned, we had a handful of NAS's with shore based ICLS and ACLS approaches, but those were de-funded and removed years ago.....I think during my first operational tour in Oceana actually. I can't honestly remember if the approaches were ever published in the NOS plates.....I seem to remember them being only printed in the Oceana Air Ops "In Flight Guide" which they guarded with great fervor. At the ship, it is basically just assumed that you will be using both systems if available, and you still fly the same CV-1 or CV-2 approach (night/IMC) which is initially TACAN based until 3 NM where you "push over" and start flying ICLS/ACLS. Actually that is not entirely true.....you get ICLS azimuth miles before that, which a smart person starts referencing to fix lineup and any required crab angle early on. But the glideslope intercept only happens at 3 miles/1200 ft. If you don't have either, you let approach know and they will give you a CCA (Carrier Controlled Approach) which in practice is similar to an ASR.

    To Pugs point, the exped. Growler/VAQ community still swaps out their ICLS boxes for civilian ILS boxes in the same manner. So at least those guys do have traditional ILS when needed. FA-18 community could theoretically have the same thing when shore based I believe, but there just isn't the funding and it also takes some maintenance work to make it happen. I might be only partially accurate on that last point, but that is my understanding.
     
  17. kkoran

    kkoran Pattern Altitude

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    I don't recall seeing the letter from the FAA, but I was at Headqurters Air Force Reaserve Command when the subsequent memo from AFFSA came out. As some others have pointed out, fix-to-fix navigation is an educated guess on the heading to the desired fix.

    VORs, TACANs, GPS, etc., have to meet accuracy requirements to be used for IFR navigation in the NAS. Fix-to-fix does not, so it is not a acceptable means of IFR navigation.
     
  18. kkoran

    kkoran Pattern Altitude

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    Look at Part 91. Some things specifically apply only to civil aircraft. The other regs apply to everyone, including the military. I think people believe that because the FAA can't take action against the pilot of a military aircraft for violations of Part 91 that it does not apply to the military. Not true. Discussed here.
    https://www.pilotsofamerica.com/community/threads/govt-aircraft-lack-faa-oversigh.45834/


    The issue isn't navigating on TACAN radials.
     
    Last edited: Sep 24, 2020
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  19. flyingron

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    Never said it was. But why is off-radial flight with TACAN any different than off-radial flight with VOR or any other non-area nav system. Even dead reconning is a valid IFR navigation technique.
     
  20. midlifeflyer

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    LOL! It takes someone special to find a cryptic hidden meaning in
    It is part of my background research for a possible article. The TACAN pseudo RNAV procedure is actually a very small part of it.

    Thank you. Although I am still hoping to find something verifiable - an FAA letter or even the memo you mentioned, your responses in this thread have been very helpful in confirming much of what I have already learned on the subject.
     
  21. midlifeflyer

    midlifeflyer Touchdown! Greaser!

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    FAA source for that statement, please.
     
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  22. flyingron

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    Which statement? You dead recon all the time IFR. You do it when intercepting courses, flying holds and PTs, etc... Even many approaches have DR legs in them.
     
  23. bflynn

    bflynn Final Approach

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    Searched the FAA site for tacan + "point to point". I found no letter, but there were many references to not using PtP with tacan because of accuracy issues. There are hints in the AIM and AIP. There's about 90 documents returned here.

    Also search for "fix to fix" and got back just a few documents, mostly 7110.65. Interesting discussion in FAA-H-8083 about tacan that uses words like "cone of confusion".

    Good thread, I've learned something this morning.
     
  24. luvflyin

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    TERPS is one. There are dead reckoning segments on Approaches. MEA gaps require it. But that’s kinda outta context with what we’re talkin about here. It’s not point to point
     
    Last edited: Sep 24, 2020
  25. flyingron

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    Again, TACAN point-to-point is a technique where you simulate area navigation to get from one point to another. It involves dead reconning. You can either do it by "visuallizing" things on the HSI and guessing or by computing stuff with your flight computer. Either way it's still technically dead reconning.

    http://navyflightmanuals.tpub.com/P-203/Tacan-Point-To-Point-Navigation-136.htm
     
  26. luvflyin

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    Yup
     
  27. luvflyin

    luvflyin Touchdown! Greaser! PoA Supporter

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    I think they may have had one of those “In Flight Guide” things at Lemoore. There was an ICLS there. No one ever got cleared for it, it never came up in any ATC communications. I had worked there for a year or so before I even knew it was there. Question, are they ‘stabilized’ on the ship or does the Glideslope rock up and down with it in heavy seas?
     
  28. midlifeflyer

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    Agreed. I think there's a difference between such things as specifically approved DR segment, VCOAs, MEA gaps, headings as opposed to course or track on an ODP on the one hand and general enroute navigation on the other.
     
  29. luvflyin

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    Yeah. You asked for a reference that has DR in it so I threw that out. But like I said, and you are now, it’s outta context with the subject here. Those things are pretty much a point to leg so to speak, not point to point
     
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  30. hindsight2020

    hindsight2020 Final Approach

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    In the USAF, the technique wasn't limited to TACAN btw, you could do it with VORs just as well. What still is true is we're not allowed to hold over them (pre-GPS substitution), for the obvious course reliability issues overhead.
     
  31. Velocity173

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    Still had a SPN-46 PALS at Miramar when I was there. At least the console that is. Was decommissioned in 97.

    AE1FBF6B-F497-45CB-B6EF-46C192307F51.jpeg
     
  32. luvflyin

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    Is that ACLS? This thing I saw was over by one of the ACLS’s. A small panel on the wall. I asked, what’s that. The person I asked said it was the ICLS monitor and it was a back up to ACLS. Are ACLS and ICLS tied to each other?
     
  33. Velocity173

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    It’s ACLS but I believe @35 AoA said ACLS and ICLS are two different components. SPN-46 is a shipboard Radar system that’s used for ACLS and select NAS facilities had the shore based version. Some of the guys told me that it could do fully automated mode I approaches with certain Navy/USMC aircraft. I know F-18s were equipped.
     
  34. Boone

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    ACLS and ICLS are different operations, with different stabilizing platforms. I don’t remember the limitations but I do remember being cautioned that the ICLS stabilization was more susceptible to ship’s movement. In ICLS, the aircraft passively received a signal. With ACLS, the ship’s radar data-linked its information to the aircraft which was displayed in the cockpit and allowed for Mode 1,2,& 3 recoveries. Occasionally, the wrong aircraft was linked to the ship and received the information intended for the preceding aircraft. I always kept Bullseye up as a cross-reference.
     
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  35. luvflyin

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    Bullseye I take it is the ICLS. Locking on to the wrong plane caused a couple ‘situations’ when I was working at Lemoore. A plane flying through final that you expected to turn to final when simultaneous approaches to the parallel runway are in progress can make things a little cozy.
     
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  36. Velocity173

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    On a side note. If you’ve ever watched The Final Countdown, in one scene at the beginning you can see an old SPN-42 display. Can even see the glide path & course lines. I’m pretty sure you don’t monitor a Russian Troller with it though. ;)
     
  37. 35 AoA

    35 AoA Pattern Altitude

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    Yeah "bullseye" is the brevity term for ICLS, whereas "needles" is ACLS. The cockpit/HUD ACLS cue (at least in the Hornet/Rhino/Growler) is a little spermy looking thing that kind of looks like a tiny bullseye, and the ICLS needles are just that. How is that for a confusing convention?

    Boone's recall is correct; ICLS is "bolted" to the ship and you will see swings of the GS needle if the deck is pitching, as well as some localizer swings since normally there is somewhat of a dutch roll component to deck movement. ACLS does offer "Mode 1" which you couple up to the jet's autopilot and has the capability to fly you down to an arrestment. I never actually did one myself, the thought of it made me uncomfortable. It tended to put guys/gals low crossing the ramp in a lot of cases, though arguably not to the extent of being unsafe for the most part. It also has no ability to fly you to touchdown if the deck is pitching.....that is all manual pilot+LSO teamwork and a little lucky timing.