Autopilot with HSI free & Pitot block
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Hi @Black-Square,
I have made two unrelated observations on the Bonanza, presuming they are also relevant for the Baron and Duke:
HSI and AP:
When the HSI gyro is free and the heading is slewed, the autopilot will follow the actual heading in HDG mode instead of the heading bug on the Gyro. An example to illustrate and reproduce:
Aircraft flying hdg 230.
Set Gyro in free mode, slew away, i.e. to gyro indicating heading 260
Set heading bug to 230 on HSI.
Aircraft will fly actual heading 230. I would expect it to turn left in this case, following the heading bug on the HSI.Pitot and static block:
When in the air and triggering a pitot block failure, the airspeed indicator indicates 0, instead of the IAS at the time of the blockage. The behaviour is observed when the static port is blocked.
Additionally, whith the AP engaged in VS mode when a static block occurs, the aircraft will level off.Hope these could be adressed in a patch

Best regards,
Marc -
I am well aware of these two failure deficiencies, as they are two of the only areas where I have no taken complete control over the systems to achieve my desired level of accuracy.
The former, I have not thought of a good way to do this without overriding the native autopilot, which becomes a near impossibility when dealing with so many different 3rd party developers for GPS units, who also override the native autopilot for their own purposes.
The latter is only slightly difficult, because MSFS does not provide a persistent indicated airspeed value (one not affected by the simulator's own sense of icing and blockages, which cause it to go to zero...), and I would worry about trusting my own derived value (that I currently use for sounds) for something as critical as airspeed.
I have wanted to tackle the entire genre of pitot/static failures for a while, but the math is fairly difficult to get them real world accurate with all lapse rate and temperature effects (high to low, look out below), and I know that is the first thing people would want to try if I make that kind of realism claim.
In short on both issues: It's never as easy as it seems, and sometimes it's an order of magnitude harder than you might even imagine.
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Hi @Black-Square,
I have made two unrelated observations on the Bonanza, presuming they are also relevant for the Baron and Duke:
HSI and AP:
When the HSI gyro is free and the heading is slewed, the autopilot will follow the actual heading in HDG mode instead of the heading bug on the Gyro. An example to illustrate and reproduce:
Aircraft flying hdg 230.
Set Gyro in free mode, slew away, i.e. to gyro indicating heading 260
Set heading bug to 230 on HSI.
Aircraft will fly actual heading 230. I would expect it to turn left in this case, following the heading bug on the HSI.Pitot and static block:
When in the air and triggering a pitot block failure, the airspeed indicator indicates 0, instead of the IAS at the time of the blockage. The behaviour is observed when the static port is blocked.
Additionally, whith the AP engaged in VS mode when a static block occurs, the aircraft will level off.Hope these could be adressed in a patch

Best regards,
Marc@topfen said in Autopilot with HSI free & Pitot block:
When the HSI gyro is free and the heading is slewed, the autopilot will follow the actual heading in HDG mode instead of the heading bug on the Gyro.
I just happened to be in the right neighborhood to spot a flag in the SDK I had never seen before to enable this behavior. I guess I didn't see it in the past, because it had no default listed, so I would not have assumed that the default behavior was for the autopilot to be driven by the magnetic compass... Glad that's working now! Nobody is probably happier at these little features than I am, haha. Thanks for putting this in my mind recently. It will be rolled out to the entire fleet after SU4.
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I am well aware of these two failure deficiencies, as they are two of the only areas where I have no taken complete control over the systems to achieve my desired level of accuracy.
The former, I have not thought of a good way to do this without overriding the native autopilot, which becomes a near impossibility when dealing with so many different 3rd party developers for GPS units, who also override the native autopilot for their own purposes.
The latter is only slightly difficult, because MSFS does not provide a persistent indicated airspeed value (one not affected by the simulator's own sense of icing and blockages, which cause it to go to zero...), and I would worry about trusting my own derived value (that I currently use for sounds) for something as critical as airspeed.
I have wanted to tackle the entire genre of pitot/static failures for a while, but the math is fairly difficult to get them real world accurate with all lapse rate and temperature effects (high to low, look out below), and I know that is the first thing people would want to try if I make that kind of realism claim.
In short on both issues: It's never as easy as it seems, and sometimes it's an order of magnitude harder than you might even imagine.
@Black-Square Nick, if you ever develop a plane without an alternate static source, a very cool failure workaround would be to be able to break the glass of the VSI or altimeter to restore the pitot-static system. You’ve already got glass tapping… give us the hammer

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@Black-Square Nick, if you ever develop a plane without an alternate static source, a very cool failure workaround would be to be able to break the glass of the VSI or altimeter to restore the pitot-static system. You’ve already got glass tapping… give us the hammer

@DangerZoneDmo That's a very amusing and creative idea

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Funnily enough, this was actually possible in the DA20 Katana by Marcel Felde (Aerosoft) for FSX, an add-on that was truly a decade ahead of its time.

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@topfen said in Autopilot with HSI free & Pitot block:
When the HSI gyro is free and the heading is slewed, the autopilot will follow the actual heading in HDG mode instead of the heading bug on the Gyro.
I just happened to be in the right neighborhood to spot a flag in the SDK I had never seen before to enable this behavior. I guess I didn't see it in the past, because it had no default listed, so I would not have assumed that the default behavior was for the autopilot to be driven by the magnetic compass... Glad that's working now! Nobody is probably happier at these little features than I am, haha. Thanks for putting this in my mind recently. It will be rolled out to the entire fleet after SU4.
@Black-Square said in Autopilot with HSI free & Pitot block:
@topfen said in Autopilot with HSI free & Pitot block:
When the HSI gyro is free and the heading is slewed, the autopilot will follow the actual heading in HDG mode instead of the heading bug on the Gyro.
I just happened to be in the right neighborhood to spot a flag in the SDK I had never seen before to enable this behavior. I guess I didn't see it in the past, because it had no default listed, so I would not have assumed that the default behavior was for the autopilot to be driven by the magnetic compass... Glad that's working now! Nobody is probably happier at these little features than I am, haha. Thanks for putting this in my mind recently. It will be rolled out to the entire fleet after SU4.
I'm very happy to see that you're coming back to this! Meanwhile I had some fun watching the magnetic compass swing left and right while toggling the windshield heat on and off again.