AI Tumble and return to operation

Discussion in 'Avionics and Upgrades' started by hish747, Sep 7, 2020.

  1. hish747

    hish747 Pre-takeoff checklist

    Joined:
    Mar 31, 2015
    Messages:
    194
    Location:
    Skylark Airpark
    Display Name:

    Display name:
    Hish747
    Today on a cross country flight (VFR thankfully) the AI started to tumble left, stayed there and then slowly returned to normal operation about 15 minutes later without another hiccup. Everything else continued to work fine. Is there a known issue that causes this? Is it just time for a new AI/G5/AV30?
    Thanks,
    Hish
     
  2. unsafervguy

    unsafervguy Pattern Altitude

    Joined:
    Aug 16, 2011
    Messages:
    1,990
    Location:
    Sw florida
    Display Name:

    Display name:
    bob
    First question, what was the vac gauge showing during all this? If vac was steady it definitely time for a G5.
     
  3. RyanB

    RyanB Administrator Management Council Member PoA Supporter

    Joined:
    Jul 21, 2010
    Messages:
    12,436
    Location:
    Chattanooga, TN
    Display Name:

    Display name:
    Ryan
    For sure... I would also not fly IFR until it’s rectified.
     
    simtech and unsafervguy like this.
  4. PaulS

    PaulS Touchdown! Greaser!

    Joined:
    May 29, 2007
    Messages:
    10,290
    Location:
    New England
    Display Name:

    Display name:
    PaulS
    I would never trust it again.
     
  5. benyflyguy

    benyflyguy En-Route

    Joined:
    Jan 1, 2018
    Messages:
    2,839
    Location:
    NEPA
    Display Name:

    Display name:
    benyflyguy
    Is your heading indicator on the vacuum or electric? What did that do if on the vacuum? If vacuum was hood time for a refurb on the AI. We did ours in our club plane-I lobbied for G5 switch but rest of club voted me down.
     
  6. hish747

    hish747 Pre-takeoff checklist

    Joined:
    Mar 31, 2015
    Messages:
    194
    Location:
    Skylark Airpark
    Display Name:

    Display name:
    Hish747
    Vacuum gauge showed normal 5" and all other instruments were fine. One thing that makes me wonder is, this only started happening after the DG was replaced. Can this be caused by a contaminant particle in the line? Seems pretty unlikely though, right? Probably time for an overhaul or G5.
     
  7. hish747

    hish747 Pre-takeoff checklist

    Joined:
    Mar 31, 2015
    Messages:
    194
    Location:
    Skylark Airpark
    Display Name:

    Display name:
    Hish747
    Well, the shop replaced the AI with an overhauled unit. 100 times worse than before. Took a 3 hour trip and the AI did cartwheels the entire way. Very frustrating since they replaced it on a Friday afternoon and we had a weekend trip planned. Does this sound like installation error or a faulty unit? The vacuum powered DG worked fine and the gauge shows 5".
     
  8. TrueCourse

    TrueCourse Pre-takeoff checklist

    Joined:
    Dec 10, 2019
    Messages:
    129
    Display Name:

    Display name:
    TrueCourse
    Sounds like vacuum supply issue unless your lucky enough to get a bad overhauled AI.
     
  9. Htaylor

    Htaylor Pre-takeoff checklist

    Joined:
    Jul 7, 2015
    Messages:
    230
    Location:
    Juneau, AK Summer, SoCal winter
    Display Name:

    Display name:
    Htaylor
    And I've had that happen.
     
  10. Getonit

    Getonit Pre-takeoff checklist

    Joined:
    Apr 15, 2013
    Messages:
    418
    Display Name:

    Display name:
    Mark
    I was on my third repair of my RC Allen gyro.....said third Garmin g5 going in. The overhaul shop just did **** poor work.
     
  11. iflyatiger

    iflyatiger Pre-takeoff checklist

    Joined:
    Mar 2, 2005
    Messages:
    303
    Display Name:

    Display name:
    iflyatiger
    I have an rc Allen electric AI I was thinking of getting overhauled, it needs it.. Could you please let me know (pm if prefer) the good and bad places to consider for the rebuild. Thanks in advance..
     
  12. Dan Thomas

    Dan Thomas Final Approach

    Joined:
    Jun 16, 2008
    Messages:
    6,734
    Display Name:

    Display name:
    Dan Thomas
    Sounds like they got the vacuum and air lines switched at the AI.