Results 1 to 7 of 7

Thread: Tach time

  1. #1

    Tach time

    I am new to the AF5500 installed in a Searey. I have rebuilt this airplane and installed a new to it Rotax 914UL. I have about 2 hours on the plane now and the Tach has only incremented by about .75 hours. I have seen that it should log anything above 1250 RPM. My idle is at 1800 RPM so I would think it should be logging more tach time that it is. Is the tach recording a settable RPM? Also can I set the tach time for the replacement engine? The engine has about 104 hours on it.

  2. #2
    Advanced Flight Systems Shawn McGinnis's Avatar
    Join Date
    Sep 2012
    Location
    Canby, OR
    Posts
    861
    An AF-5000 will accumulate tach time for the Rotax above 3500 RPM. Hobbs for Rotax will accumulate above 500 RPM. You can adjust the values from within Calibration -> Admin Settings -> Set Tach and Hobbs Time
    Shawn McGinnis

    Advanced Flight Systems
    support@advanced-flight-systems.com

  3. #3
    Shawn (or Jonathan), this is an old post but we have a SeaRey too and are trying to understand the Hobbs vs Tach settings. I have gone into Calibration -> Admin Settings -> Set Tach and Hobbs Time, and I can see that I could change the Hobbs and Tach numbers (I think that is what it allowed but I don't want to change them) but I don't see how to see how to tell what the RPM thresholds are, nor how to change them (assuming I can change the RPM numbers).
    Last edited by Harold Roberts; 08-13-2022 at 06:58 PM.

  4. #4
    You can manually change the hobbs and tach times, but you cannot change the RPM crossover threshold.

  5. #5
    Jonathon, thanks. Is there any way to be assured that our SeaRey RPM settings are really 3500 and 500 by looking into the settings or should I simply trust that all SeaReys (with Rotax) are set to the same? The reason I ask is our A&P wants to be 100% sure for the purposes of meeting Rotax required maintenance periods. Rotax measures the hours of the engine by the time it is started to the time it is turned off. By the settings above, the Hobbs is what we want since the engine will always be above 500 rpm when it is started.

  6. #6
    Harold yes it sounds like you should use Hobbs time and not tach for scheduling your engine maintenance.

  7. #7
    Advanced Flight Systems Shawn McGinnis's Avatar
    Join Date
    Sep 2012
    Location
    Canby, OR
    Posts
    861
    You can verify which engine type is selected by looking in calibration -> Aircraft Info -> Engine Type.
    ROTAX 2 EGT, ROTAX 4 EGT, ROTAX 912iS, ROTAX 915iS all have >3500 RPM will increase the TACH time and >500 RPM will increase the HOBBS time
    Shawn McGinnis

    Advanced Flight Systems
    support@advanced-flight-systems.com

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •