Mechanical Stall Warning??

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Vans have supplied the kit with two pilot holes ready for the Stall Warner Vane slot.

I have asked the LAA (Light Aircraft Association, UK) whether I will be compelled to fit a mechanical stall warner, since I plan to fit a pitot probe with AOA. This will of course be displayed on an EFIS with audio warning.

I suspect I’ll need to apply for an official modification, but in the meantime I’ve decided not to cut the slot. Instead I’ve machine countersunk the holes & fitted small OOP’s rivets.

If it turns out that I have to fit a stall warning vane after all, I’ll drill out the rivets and open up the holes to #10 as per the manual, and file the slot. Apparently there are several RV7’s & 8’s in the UK flying with no mechanical stall warner, so it bodes well, but fingers crossed

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I’ve prepared the brackets that attach the stall warning microswitch, and will also rivet the relevant nutplates to the left inboard LE rib just in case it has to be incorporated.

5 Comments on "Mechanical Stall Warning??"

  1. Bill Sweetnam | June 16, 2019 at 10:16 am | Reply

    Hi Steve… great blog!
    I’m on the home straight with my 14 QB tail dragger…full G3x ifr installation…
    Also wondering about the mechanical stall warner…did you ever get a ruling on this? Otherwise I’ll just leave wires in place and be able to fit later.

    • Hi Bill … thanks for your comment. I contacted the LAA who said the following … “In summary, yes, we’d be happy for you to use the Garmin AoA system in lieu of a mechanical stall warning device, subject to the test pilot confirming that it gives an appropriate/obvious warning of an impending stall and the visual component of the warning is also sufficiently clear.” They said they are planning to publish a Technical Leaflet about this topic, but I haven’t seen anything yet. I’ve sent you a private email with a little more info.

  2. Mark Browning | May 11, 2020 at 10:02 pm | Reply

    Hi Bill
    I’m building a 14 in Doncaster
    I’m planning my avionics and did not fit a stall Warner
    When I built the wings with the intention of using the AOA
    And Garmin 3GX
    Would it be possible for you to forward any details or confirmation on this please
    I really need to nail this down before I paint the wings
    Many thanks

  3. Hi Mark … I’ve heard nothing different from the LAA than my original reply to Bill last June (see above). Just sent you an email.

    • Mark Browning | May 11, 2020 at 10:24 pm | Reply

      Thanks Steve

      Our RV-7 has Dynon D100 with AOA and no stall Warner
      To be honest I’ve flown all the RV’s and there’s no problem with stall , they give you lent of warning although the 8 is a little more slippery.
      It could be our aircraft engineer never picked It up, unfortunately He recently passed away. We have being flying this for ten years.
      I have to get to confirmation on this from LAA or my engineer
      Before I paint later this year
      Thanks for all your help 👍
      Best regards

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