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  • airspeed on final approach

    I have been trying to lower my airspeed on final approach and am concerned because my stall warning will occasionally sound. This seems to happen around 55 knots IAS in light wind conditions, sometimes even at 60 knots IAS if there is mild wind gusts. I have a 260SE and am thinking the plane will stall around 38 knots with 20 degrees of flaps so. My POH states that at 20 degrees of flaps, 50 Knots IAS calibrates to 57 knots and 40 Knots IAS calibrates to 50 knots. I typically fly by myself or with one other 125 lb passenger. My gross weight is typically less than 2600 lbs. I think an approach speed of 55 KIAS should give me a healthy margin of safety in all but very gusty conditions. So my questions are:
    1. Should I trust the stall warning horn or trust the airspeed indicator?
    2. Am I correct in that the 260SE should stall around 38 knots IAS?

    Any advice or comments would be appreciated.

  • #2
    Mike

    Provided that your canard system is properly rigged and has not been degraded by well-intentioned (or presumptuous) fiddling by ignorant mechanics, 55 KIAS should be more than adequate--maybe even a touch fast!--for the conditions you describe.

    Note that your CAS figures are for the stock 182. They will not be accurate for the flatter pitch attitudes conferred by the canard at slow speeds.

    Just for reassurance, you might try going out and doing some coordinated power-off and power-on stalls at a safe altitude and see for yourself how much margin you have. I'm sure you'll be considerably (and pleasantly) surprised.

    I'm guessing Todd will be able to provide an authoritative answer in the next couple of days.

    I also strongly recommend that, if it's at all possible, take a trip in your plane out to El Dorado for some 1:1 with Todd, or find an experienced Peterson pilot near you.
    Kevin Moore
    Former 260se/stol Katmai with BRS owner; planeless for now
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    • #3
      Yes, doing some stalls at altitude is a good idea. Thanks Kevin.

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      • #4
        You might also read/review post #2 in this thread.
        Kevin Moore
        Former 260se/stol Katmai with BRS owner; planeless for now
        sigpic

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        • #5
          The stall warning indicator can go off anywhere from 3 knots above stall speed to 20 knots depending on how it is set up. 55 knots on final is a reasonable speed for final with a 260SE but remember the slower you go the less lift and energy you have available thus you need to be further ahead of the airplane. A lot also depends on the temperature, wind, load, etc. On days that are really windy I will add half the gust factor to my approach speed just like a regular airplane. As you come in slower you also need to leave just a little power in on the approach and flare and you do not chop the power as you would do with a 60 knot approach. Things change when approaching below 60 knots and one just has to know what to do when things start to go wrong. Above all don't drag the airplane in at 55 knots. Rather keep the final approach with a reasonable rate of descent, maybe 400 fpm or so. There isn't any reason you can figure this out for yourself but be careful. Work the airplane on a calm day with half tanks when experimenting. It only takes one bad move to ruin your day and your airplane.

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          • #6
            Thanks for the insights Todd and Kevin. Kevin, I believe you had a G500 in one of your planes. I just installed one and my attitude indicator indicates a 2 1/2 to 3° climb during straight and level. I am just wondering if this may be occurring because of the avionics shop did not take the canard into account. I will contact the shop to have it corrected but I was just wondering if you ran into a similar problem.

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            • #7
              Originally posted by Mikearmentano View Post
              Thanks for the insights Todd and Kevin. Kevin, I believe you had a G500 in one of your planes. I just installed one and my attitude indicator indicates a 2 1/2 to 3° climb during straight and level. I am just wondering if this may be occurring because of the avionics shop did not take the canard into account. I will contact the shop to have it corrected but I was just wondering if you ran into a similar problem.
              You can see photos of what my G500 display looked like in cruise and various other regimes here. I asked the shop that did the installation to set "straight and level" at about 130 KIAS. It seems they did a good job of it. I loved flying with the G500; a PIREP is here.
              Kevin Moore
              Former 260se/stol Katmai with BRS owner; planeless for now
              sigpic

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              • #8
                Thanks for the pics Kevin

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