? For ATC; varying speed under IFR flight plan

Discussion in 'Cleared for the Approach' started by JOhnH, Dec 12, 2020.

  1. JOhnH

    JOhnH Touchdown! Greaser!

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    I recently had a couple of cylinders overhauled. Part of the break-in process is to vary the power between 65% AND 75% every 15 minutes. If I am under an IFR flight plan will it annoy anyone or cause any issues if I keep varying my speed up and down for a while?
     
  2. luvflyin

    luvflyin Final Approach PoA Supporter

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    Maybe. How many knots we talkin about?
     
  3. Brad Z

    Brad Z Final Approach

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    The controller will never notice.
     
  4. Radar Contact

    Radar Contact Pattern Altitude

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    ATC won’t notice or care about 10% of any plane that has cylinders. :)
     
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  5. Larry in TN

    Larry in TN Pattern Altitude

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    The official answer is 5% or 10 knots, whichever is greater, per AIM 5-3-3. 5% doesn't come into play until your TAS is over 200 knots.

    The issues would be when you're sequenced behind, or in front of, other traffic on the same route. That's more of an issue for jets or outside of radar service.
     
  6. gacoon

    gacoon Pre-takeoff checklist

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    How will they know its you or a wind change, especially if your speed doesnt change that much,
     
  7. luvflyin

    luvflyin Final Approach PoA Supporter

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    because another plane in the same wind starts overtaking or being overtaken by you. But like you said if the speed difference is small it ain’t gonna be a big deal. Plenty of time for the controller to respond to it.
     
  8. N1120A

    N1120A Pattern Altitude

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    I once had a controller tell me to climb and maintain 15000. I said "unable" (no O2 and that's not a good altitude for a NA piston anyway) and was kinda shocked. I'd filed for and been cleared to 11000 by tower. Dead air. "Oh, that's your speed, maintain 11000."

    I really doubt they care, unless there is someone else bearing down on you or that you are bearing down on.
     
  9. JOhnH

    JOhnH Touchdown! Greaser!

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    Thanks everyone. We are only talking about maybe a 10 kt diff (From 160 to 170).
     
  10. frfly172

    frfly172 Touchdown! Greaser!

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    As long as they don’t have to adjust other aircraft because of your speeds ,there shouldn’t be a problem.
     
  11. Larry in TN

    Larry in TN Pattern Altitude

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    Right. They don't care, until they do. No way for a pilot to know when they will, or will not, care.

    Well, A 10 knot change is the trigger, for TAS up to 200 knots, for a report under AIM 5-3-3, so shoot for 9.9 knot changes and you don't have to worry about it.
     
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  12. Busflyer

    Busflyer Pre-takeoff checklist

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  13. Timbeck2

    Timbeck2 Final Approach

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  14. 4CornerFlyer

    4CornerFlyer Pre-takeoff checklist

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    I think this would be more of an issue in a non-radar environment, meaning few places in the continental US. If you're on radar, the controller knows you speed--at least the speed that matters. That being said, the AIM does specify what you are supposed to do.
    Jon
     
  15. AeroLudite

    AeroLudite Pre-Flight

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    File for the lower speed. No one will notice or care. I’ve only been told to maintain maximum forward speed! Never slow down except by tower controller at Orlando Exec. I was in a Turbo Saratoga, kept calling me a Cherokee . Lots of Skyhawks in the pattern...