ark

HSI Red Bearing Pointer

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Hi all,

Just wanted to point out a few things about the red HSI bearing pointer in the Falcon 50 since the aircraft manual lags updates somewhat.

If in GPS mode, and you have a GPS flight plan or waypoint set up, the diamond end of the bearing pointer should point to the next GPS waypoint. In GPS mode the new ADF/VOR switch (see the FSW Thread F50 New Feature below) has no function.

If in VLOC and you have a valid VOR signal in NAV1, and the ADF/VOR switch is down (VOR position) the diamond end of the bearing pointer should point to the VOR station.

If in VLOC and you have a valid ADF signal in ADF1, and the ADF/VOR switch is up (ADF position) the T end of the bearing pointer should point to the NDB or source of the ADF signal.  Admittedly this seems somewhat strange (at least to me) but that is the way the real instrument works according to the documentation.

The ADF OFF position for the bearing pointer is horizontal with the T end of the pointer pointing to the 90 degree position relative to the HSI lubber line.

The VOR OFF position for the bearing pointer is straight down with the diamond end of the pointer pointing 180 degrees relative to the HSI lubber line.

If in GPS mode, the OFF position for the bearing pointer (no GPS flight plan or waypoint set up) is North, that is the diamond end of the bearing pointer will point to Magnetic North on the HSI compass card.

In selecting the ADF/VOR switch positions, and the bearing pointer 'needle' OFF positions, the intent was to be consistent with the RMI gauge.

Al

 

Edited by ark
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Hi Al:

Running latest Beta 4.5, or maybe 5.2 I think. Fresh download this morning.

Maybe I am misunderstanding this a bit but right now I am flying in GPS mode and ALT on the autopilot panel with a flight plan active in my F1 GTN 750. On the HSI a red symbol looking like a T is at the top and a red symbol looking kinda like a diamond laying on it's side is at the bottom. And I do not see a solid red line. The only solid line in the HSI is the green line which appears to be inactive as I don't have an ADF or VOR teed up. Am II getting this?

Thanks

Rick

Edited by Wink207

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22 minutes ago, Wink207 said:

Hi Al:

Maybe I am misunderstanding this a bit but right now I am flying in GPS mode and ALT on the autopilot panel with a flight plan active in my F1 GTN 750. On the HSI a red symbol looking like a T is at the top and a red symbol looking kinda like a diamond laying on it's side is at the bottom. And I do not see a solid red line. The only solid line in the HSI is the green line which appears to be inactive as I don't have an ADF or VOR teed up. Am II getting this?

Thanks

Rick

The red bearing pointers do not span the HSI. The actual HSI is not an electronic display, but a mechanical instrument, so all of the various pointers are electrically driven by internal servos. The red pointer symbols rotate around the periphery of the compass card, and are always directly opposite each other. If the red pointer source is ADF, the "T" symbol represent the relative bearing "TO" the tuned NDB. If the bearing source is VOR or GPS, then the diamond symbol represents the "TO" bearing.

The green pointer is your course deviation indicator which is used with VORs and localizers, and will show course deviation when tracking a GPS flight plan in NAV mode.

The CDI course must be physically set by the pilot to match the VOR radial or ILS localizer course. When using a Garmin GNS or GTN GPS, the GPS screen will display a message when a course change is upcoming to tell you what course to set the green pointer to.

With an electronic "glass cockpit" HSI, the Nav receiver or GPS can adjust the course of the CDI needle automatically since the green needle is just a digital image, but with a mechanical HSI such as found in the Falcon, the pilot must do it. 

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3 hours ago, JRBarrett said:

 

 When using a Garmin GNS or GTN GPS, the GPS screen will display a message when a course change is upcoming to tell you what course to set the green pointer to. 

 

Thank you for the explanation. Very helpful. The quote above tells me that, when in GPS mode, the green line will no longer automatically track the GPS heading and the pilot needs to make an adjustment if one desires the green line to lie along the flight plan heading. This is a change, correct?

Thanks

Rick

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1 hour ago, Wink207 said:

Thank you for the explanation. Very helpful. The quote above tells me that, when in GPS mode, the green line will no longer automatically track the GPS heading and the pilot needs to make an adjustment if one desires the green line to lie along the flight plan heading. This is a change, correct?

Thanks

Rick

Yes. In the first few betas, the green pointer did auto-track GPS course changes, but since a mechanical HSI can’t actually do that, the auto mode has now been disabled. 

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The auto-track feature can be re-enabled in either of the GPS units. It is a 'realism' issue up to the user to decide. And of course, the Falcon 50 is a two crew a/c in the real world, so one could argue that a little help is not unreasonable.  😉

Al

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Thanks guys and yes I like realism and I like the idea that electro-mechanical systems are not perfect. This realism keeps us pilots on our toes. In the RW, nothing is ever perfect.

Rick

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