Ray Proudfoot

Wrong heading on EHSI - why?

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UPDATE: Just found the answer supplied by Bert on another post with the same problem. Gyro Drift sorted by pressing D. But how often does that need pressing?

It's been a long time since I flew a light aircraft with these navigation instruments but having just landed on Rwy 25 at EGAA where the runway heading is 250 can anyone please explain why the EHSI shows a heading of 331°? Hope that isn't a daft question:smile:.

The NAV/GPS Mode switch is in NAV mode and NAV1 is selected.

On a slightly different note is it possible for the aircraft to fly heading automatically with a flight plan loaded? I normally fly Concorde which does have that option of course as do all Boeing / Airbus aircraft.

EGAA_Rwy25.png?dl=0

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It is a bug,  I believe... in some planes I have added a little routine to set it automatically.

Make sure that Gyro drift is turned off wherever you can.. or this can happen..

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Thanks Bert. I shall set Drift to Off. A few degrees is reasonable but 90?? :blink:

Could you answer my other question please? Is there any way the route can be flown by instruments only or does it require the pilot to manually change the GPS heading for the active waypoint?

I suppose I'm not used to all this manual stuff! :biggrin:

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9 minutes ago, Ray Proudfoot said:

Thanks Bert. I shall set Drift to Off. A few degrees is reasonable but 90?? :blink:

Could you answer my other question please? Is there any way the route can be flown by instruments only or does it require the pilot to manually change the GPS heading for the active waypoint?

I suppose I'm not used to all this manual stuff! :biggrin:

Ray,

If you set the nav mode to GPS in the GTN 750 or 530; it should shift your heading to active leg in the HSI.

Greg

 

 

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In the real world, small airplanes expect you to manually check/adjust the HSI heading every 15 mins to match the magnetic compass.

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18 minutes ago, gregmorin said:

Ray,

If you set the nav mode to GPS in the GTN 750 or 530; it should shift your heading to active leg in the HSI.

Greg

Thanks Greg. I believe I'm doing that already but it does require pilot input to change the heading to the one indicated by the GPS Mode. I am changing that manually (adjusting for wind influence) but wondered if the a/p was sophisticated enough to do it itself.

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4 minutes ago, Ray Proudfoot said:

Thanks Greg. I believe I'm doing that already but it does require pilot input to change the heading to the one indicated by the GPS Mode. I am changing that manually (adjusting for wind influence) but wondered if the a/p was sophisticated enough to do it itself.

The HSI should automatically show the active GPS course, if the GPS is in GPS mode (not VLOC) and the HSI is in GPS mode also.

And the autopilot will automatically fly the GPS flight plan when in NAV mode.

What kind of GPS are you using in this airplane?

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Errrr...why not just set GyroDrift=False in the Prepar3d.cfg [REALISM] section?  (Or uncheck the option in the sim's realism settings menu.)

Regards

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It is showing the course to the next waypoint. What I'm asking is can the a/p change heading to fly to that waypoint?

I'm using the default GPS supplied with the PC-12. Are there alternatives?

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2 minutes ago, w6kd said:

Errrr...why not just set GyroDrift=False in the Prepar3d.cfg [REALISM] section?  (Or uncheck the option in the sim's realism settings menu.)

Regards

I shall be doing that but using SimStarterNG. :smile:

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5 minutes ago, Bert Pieke said:

And the autopilot will automatically fly the GPS flight plan when in NAV mode.

I missed that bit. I'll double check on my next flight, thanks.

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12 minutes ago, Ray Proudfoot said:

It is showing the course to the next waypoint. What I'm asking is can the a/p change heading to fly to that waypoint?

I'm using the default GPS supplied with the PC-12. Are there alternatives?

The Flight1 GTN750 is a great GPS for this airplane.

http://www.simforums.com/forums/flight1-gtn-in-pc12-v2_topic57846.html

It will change everything.. try downloading a copy of the free Gamin GTN Trainer

and run it separately from the sim, to see the functions..

If you get it, contact me for my latest PC12/GTN fixes.

ps You can also replace the crummy Carenado GNS by an RXP or Flight1 GNS.. but I would suggest getting the GTN instead.

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Compatible with FSX, FSX-SE, P3Dv3.x and P3dv4.x

Worth it?  I think so...it's a full implementation of both of the Garmin GTN units (GTN650 and GTN750) using Garmin's own FTD software as its core.  It gives you a touch-screen navcom system with TAWS and TCAS, and a whole lot of real-world bells and whistles.

Regards

 

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Bob,

Maybe if it's your primary aircraft. As I said earlier I have EFB which gives me navigation info and a whole lot more on a separate display running WideFS.EFB

I notice the terrain data is only for Nth America too. Each to their own. :wink:

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Ray - Looks like you found my thread from back in the day.

I have noticed that if the engine is started before the plane moves, there isn't a heading sync problem.

What's odd, this is the only Carenado plane that has this problem. I don't encounter heading sync issues with the 9 other products I own from them. I also have the gyro drift turned off (unchecked) and I still have this problem, as well as the requirement to adjust the sync (by pressing D) every 100 or so nautical miles in the air. It'll still drift 2-3 degrees.

 

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2 hours ago, Ray Proudfoot said:

Bob,

Maybe if it's your primary aircraft. As I said earlier I have EFB which gives me navigation info and a whole lot more on a separate display running WideFS.EFB

I notice the terrain data is only for Nth America too. Each to their own. :wink:

It comes with a Worldwide database.. some things like airport approach charts are North America only..

Your call.. :happy:

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@softreset, yes Mark it was your post. I should have searched first. :smile:

Now that I’m aware of the issue I’ll continue to check for it. Strange that the problem continues even with drift disabled. I can probably live with 2-3 degrees but not 90! :biggrin:

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1 hour ago, Bert Pieke said:

It comes with a Worldwide database.. some things like airport approach charts are North America only..

Your call.. :happy:

For that price I would expect worldwide coverage of everything. I’ll give it a miss thanks.

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I too have noticed the heading gyro drift with P3D gyro drift off in the realism settings. I know I’m slipping into the Real World here, but aren’t the AHRS “slave” switches supposed to sync the heading gyro with the magnetic compass? Carenado/Alabeo have done this with their other aircraft, notably the Alabeo Titan c404. I wonder what part of the software code addresses this?

Lantz

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12 hours ago, LZScout said:

I too have noticed the heading gyro drift with P3D gyro drift off in the realism settings. I know I’m slipping into the Real World here, but aren’t the AHRS “slave” switches supposed to sync the heading gyro with the magnetic compass? Carenado/Alabeo have done this with their other aircraft, notably the Alabeo Titan c404. I wonder what part of the software code addresses this?

Lantz

You can just write a line of code that checks for HSI vs Compass heading and reset it,  if different..

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Easier said than done Bert. You're the master with this stuff. I'm assuming you are talking about a line of code inserted in the aircraft.cfg file? what would the format be?

 

Lantz

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2 hours ago, LZScout said:

Easier said than done Bert. You're the master with this stuff. I'm assuming you are talking about a line of code inserted in the aircraft.cfg file? what would the format be?

 

Lantz

No, that would have to be inside a gauge... sorry..

In this case, the EHSI gauge would be a good place.

Something like:

(A:Plane heading degrees gyro, degrees) flr (A:PLANE HEADING DEGREES MAGNETIC, degrees) flr != if{ 1 (>K:HEADING_GYRO_SET) }

Translated:  If the Gyro Heading and Magnetic Heading differ by more than a fraction, reset the Gyro Heading.

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Hi Folks,

Yep - RW - Directional Gyros need to be reset (gyroscopic precession) continually especially when making many substantial heading changes - slaved HSI's usually once before flight... The slaved HSI can have no compass input which requires it to be manually set for each flight while it compensates for errors once set... I don't know how this works with glass HSI's...

Regards,
Scott

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