Deviation from the planned route in magenta line (FMS)

Find out more before you buy, or chat to other KA pilots!
(No support requests please)
Post Reply
ramon.cutanda
Posts: 20
Joined: Sat Jul 12, 2014 5:41 am
Location: Cieza - Murcia - Spain
Contact:
Deviation from the planned route in magenta line (FMS)

Post by ramon.cutanda » Mon Jun 01, 2015 11:17 pm

Before I actually make my question, I would like to clarify some points:

1. I am a complete newbie. I have only completed half a dozen flights with the 350i. There is no documentation so I will be probably doing TONS of things wrong.

2. I am perfectly aware this product is a "beta" version still under development prone to bugs and other unexpected behaviours.

Now. To the point. have a look a this picture:

Image

Which one is "lying"? A or B? It is not possible to be following the line and having a deviation at the same time. So one of the screens is lying.

So, am I doing something wrong? Is this a bug? Which one should I believe?

Thanks for the info :-)

Bests,

PS: I am running vA2.150304

jzimmermann
Posts: 166
Joined: Mon May 20, 2013 12:16 pm
Re: Deviation from the planned route in magenta line (FMS)

Post by jzimmermann » Tue Jun 02, 2015 1:09 am

Hi there Ramon,

The 350i is actually still in Alpha and has not yet reached Beta. :)

I would say that both are correct. Your zoom level on Screen B is at it's highest level zoomed in, and since your wind is coming from roughly 92 degrees, your actual flight vector will be offset to compensate for the wind coming out of the east.

If you zoom out using the Range knob between the PFD and MFD, then you should see the line getting much closer to the aircraft and have less of a "lying" appearance. :lol:

Cheers,

Jerome

ramon.cutanda
Posts: 20
Joined: Sat Jul 12, 2014 5:41 am
Location: Cieza - Murcia - Spain
Contact:
Re: Deviation from the planned route in magenta line (FMS)

Post by ramon.cutanda » Tue Jun 02, 2015 8:10 am

Thanks Jerome for your prompt and helpful reply. It is true that I made the screeshot with the highest level of zoom. But even with higher values (up to 80nm) you can notice the deviation. As I said, I am aware this is a product still under development, but I just wanted to know a little bit more about it.

Thanks again,

KenG
Posts: 144
Joined: Sat May 09, 2015 2:33 am
Re: Deviation from the planned route in magenta line (FMS)

Post by KenG » Tue Jun 02, 2015 11:34 am

I disagree with Jerome. The map mode and the HSI should show the same deviation from desired course regardless of winds. With a stiff crosswind you may see a heading that differs from your computed desired track, but when the crosstrack (XTX) on the FMS reads 0 (NAV page 1, 4L position) then both the HSI and the Map mode should display zero offset. Unless you are using SXTX (selective crosstrack.)

I have seen this as well but have been unable to duplicate it with consistency to report as a bug. Glade you captured a photo.


v/r

-Ken
-Ken
King Air Instructor
CFI, CFII, MEI

ramon.cutanda
Posts: 20
Joined: Sat Jul 12, 2014 5:41 am
Location: Cieza - Murcia - Spain
Contact:
Re: Deviation from the planned route in magenta line (FMS)

Post by ramon.cutanda » Tue Jun 02, 2015 9:08 pm

Even with lower zoom ranges the deviation is pretty noticable:

Image

On the other hand, I am not actually asking for help or support. I'm just pointing out something I have found weir, so I would leave up to the mods where to place this thread and what to do with the info.

Bests,

QCman
Posts: 94
Joined: Sat Feb 18, 2012 1:22 am
Re: Deviation from the planned route in magenta line (FMS)

Post by QCman » Thu Jun 04, 2015 2:33 pm

Deviation on the PFD is right, but on the MFD (map mode) it's a line drawing. When 2 waypoints are far away, we are not drawing a arc (earth is round).

Sorry, I just don't know how to do this calculation.

JonathanBleeker
Posts: 9379
Joined: Sat Mar 13, 2010 7:38 pm
Re: Deviation from the planned route in magenta line (FMS)

Post by JonathanBleeker » Thu Jun 04, 2015 4:13 pm

David I think I can come up with something....Ill let you know by email.
-JB

Milviz R&D Lab dev/Resident PITA Perfectionist.


Image
Please read the manual before posting. You will learn quicker than if I act as your instructor.

ramon.cutanda
Posts: 20
Joined: Sat Jul 12, 2014 5:41 am
Location: Cieza - Murcia - Spain
Contact:
Re: Deviation from the planned route in magenta line (FMS)

Post by ramon.cutanda » Thu Jun 04, 2015 10:15 pm

we are not drawing a arc
That answers my question... Thanks!!!
I think I can come up with something
Great!

I'm glad I could come up with something to improve this great product.

Bests,

Krazycolin
Site Admin
Posts: 10005
Joined: Mon Sep 08, 2008 4:18 pm
Re: Deviation from the planned route in magenta line (FMS)

Post by Krazycolin » Fri Jun 05, 2015 3:25 am

No promises here...
Creative Director and chooser of planes.

KenG
Posts: 144
Joined: Sat May 09, 2015 2:33 am
Re: Deviation from the planned route in magenta line (FMS)

Post by KenG » Fri Jun 05, 2015 1:10 pm

Gentlemen,

I don't know if this helps, but here is a mad math page on aviation formulas for great circle navigation. http://williams.best.vwh.net/avform.htm#GCF

When it comes to this stuff I am a pilot and I did not major in math. Anything more complicated then time, distance, and heading in which I can pull out my old trusty never need batteries E6B, then I am done for. :D

v/r

-Ken
-Ken
King Air Instructor
CFI, CFII, MEI

jzimmermann
Posts: 166
Joined: Mon May 20, 2013 12:16 pm
Re: Deviation from the planned route in magenta line (FMS)

Post by jzimmermann » Fri Jun 05, 2015 6:59 pm

KenG wrote:Gentlemen,

I don't know if this helps, but here is a mad math page on aviation formulas for great circle navigation. http://williams.best.vwh.net/avform.htm#GCF

When it comes to this stuff I am a pilot and I did not major in math. Anything more complicated then time, distance, and heading in which I can pull out my old trusty never need batteries E6B, then I am done for. :D

v/r

-Ken
Bloody hell, some really good info there, great stuff Ken!

Cheers,

Jerome


Post Reply

Return to “K.A.350 General Forum”