Possible bug - stuck air speed
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First flight in the Caravan I think I ran into a bug. My airspeed got stuck around 150 knots. I think it happened when I adjusted the true airspeed dial on the airspeed indicator. I noticed it in my descent that my airspeed wasn't changing and REALLY noticed it on approach. It affected both the pilot and copilots air speed indicators as well as the air speed indications on the GTN750 density altitude page. I flew the approach and landing using the ground speed indication on the GPS. Checked on the tablet and none of the covers were in place and no failures shown on the failure page. I have it on video if you'd like me to upload so you can see.
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I just had the same thing happen on my fourth flight (no issues on my first three). Flew from Bethel to Fairbanks, AK at 5000’ and at some point near the end of the journey the airspeed was stuck at 160kt. I had the pitot and stall heats on the whole time and no failures were indicated on the tablet. I realized during my initial approach that something was definitely wrong with the speed. I tried tapping on the glass but no change. This also affected the copilot ASI. I also tried switching to alternate static source with no effect.
There was light icing during the journey but nothing that windshield and prop heat wouldn’t clear in a few seconds. No noticeable airframe icing.
The ASIs remained stuck at 160kt after landing and shutting down.
Not sure it helps but I had the PMS 750/650 in all four flights and used a sim rate adjustment in at least two or three for a portion or cruise and it was only the latest flight that had an issue.
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I just had the same thing happen on my fourth flight (no issues on my first three). Flew from Bethel to Fairbanks, AK at 5000’ and at some point near the end of the journey the airspeed was stuck at 160kt. I had the pitot and stall heats on the whole time and no failures were indicated on the tablet. I realized during my initial approach that something was definitely wrong with the speed. I tried tapping on the glass but no change. This also affected the copilot ASI. I also tried switching to alternate static source with no effect.
There was light icing during the journey but nothing that windshield and prop heat wouldn’t clear in a few seconds. No noticeable airframe icing.
The ASIs remained stuck at 160kt after landing and shutting down.
Not sure it helps but I had the PMS 750/650 in all four flights and used a sim rate adjustment in at least two or three for a portion or cruise and it was only the latest flight that had an issue.
@Iconography said in Possible bug - stuck air speed:
I had the pitot and stall heats on the whole time
Unless someone else has seen this in the tropics, far away from any icing conditions, I think the problem was actually found by another user, which was a single character mistake that rendered the pitot heat inoperable if both the stall heat and pitot heat switches were on.
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@Iconography said in Possible bug - stuck air speed:
I had the pitot and stall heats on the whole time
Unless someone else has seen this in the tropics, far away from any icing conditions, I think the problem was actually found by another user, which was a single character mistake that rendered the pitot heat inoperable if both the stall heat and pitot heat switches were on.
@Black-Square that would make sense! I noticed during my preflight that it looked like the generator amps dropped when both switches were on but I thought I surely must have been misunderstanding what I was seeing.
