windsock problem?

Gender: Joined: 28 Nov 2009 Posts: 3

Hello there,

I've noticed that the windsocks indication is wrong, it seems that wind course rapresentation is displaced of about 90°.

I'll try to explain better:

Lined up on rwy 10.. (mag 103°)

let's put some headwind for example... from 101° at 36 kt

and now let's check inside the scenery...
As you can see from the screen my heading was 102° magnetic with a wind direction of 111° magnetic and a speed of 36 kt... now look at the wind sock: WRONG INDICATION!

I'm the only one who looks at windsocks before landing? Laughing

Or i'm the only one with this problem?? (note that with other sceneries i've got correct indications).

Ahhh, I'm exlcluding magnetic declination, both heading and wind direction are magnetic... so no problem.

Exclamation

Let me know

regards

Posted: Sat Nov 28, 2009 10:13 pm (No subject)

I'm sure Bill will show up here at some point to reply Smile

Posted: Wed Dec 02, 2009 10:03 pm (No subject)

Hello:

I also had to do a bit of learning about windsocks not so long ago... as this thread illustrates (I mixed up the concepts of Wind "Direction" and Wind "Heading") : Idea

http://forums1.avsim.net/index.php?showtopic=246901&hl=GaryGB+windsock

My apologies to Bill W. for my initial misunderstanding of the 2B2 windsocks ...as I'm a novice pilot that has not had formal training in the finer points of aviation ! Embarassed

I plead guilty as follows...

"And let's get one thing straight. There's a big difference between a pilot and an aviator. One is a technician; the other is an artist in love with flight." — E. B. Jeppesen

http://www.skygod.com/quotes/piloting.html

[EDITED]

PS: As the FSAddon Manual for Plum Island does not provide a copy of the FAA airport chart for Plum Island, here's one:

http://www.airnav.com/airport/2B2

Note: This chart lists MagVar as 16 Degrees West; that correlates with the readout in my screenie below (zoom in as needed).

Perhaps this might help as an example for interpreting the scenario above:

"Magnetic Variation will also be indicated in the airport diagram. This can be used to determine winds in Degrees Magnetic from a METAR weather sequence which reports winds in Degrees True. In the case of Halifax with 20° west, you would add the 20° to the METAR wind direction to get the magnetic direction of winds, so if you saw 09027 on a METAR, the winds at Halifax would be 110°M at 27 knots."

http://bathursted.ccnb.nb.ca/vatcan/fir/moncton/WeeklyTopics/Archives/20030608/CurrentTopic.html

"Wind Direction vs. Wind Heading

There is sometimes confusion between the terms

"Wind Direction" and "Wind Heading"...

"Wind Direction" means "the direction where the wind is coming from"

...whereas...

"Wind Heading" means "the direction where the wind is going to"

...for example...

In the case of a northerly wind direction, the wind is coming from the north and going to the south.

Wind direction and heading differ by 180 degrees. "

http://www.windspeed.co.uk/ws/index.php?option=faq&task=viewfaq&Itemid=5&artid=17

...Some other interesting related links I found "Blowin' In The Wind" :

http://en.wikipedia.org/wiki/Wind_triangle

http://hyperphysics.phy-astr.gsu.edu/hbase/airpw3.html

GaryGB

Gender: Joined: 28 Nov 2009 Posts: 3

Interesting explanation man, but FS gives MAGNETIC wind and MAGNETIC aircraft heading. So the windsock is buggy.

Posted: Fri Dec 04, 2009 1:47 pm (No subject)

No idea. Maybe we should better take 0,005 cent off the price of the product Shocked

Posted: Fri Dec 04, 2009 8:06 pm (No subject)

Hi Ardix:

I've posted below some screenies below to try and better understand this scenario before offering the modifications I already made for the Windsocks used in my "2B2 Nocturnal Immersion" add-on scenery package at Emma Field Forum. Smile

Picture 1: I set a "Wind Direction" 0 Degrees at 16 kts in FSX

NOTE: FS allows us to set "Wind Direction"... NOT "Wind Heading"

Picture 2: My current Windsock "XML Placement Headings" with a "Wind Direction" of 0 Degrees at 16 kts at 2B2 in FSX

Picture 3: Proposed Instant Scenery Windsock "3-D World Object Heading" at 5 Degrees, with a "Wind Direction" of 0 Degrees at 16 kts at 2B2 in FSX

Lets make a "deal": Idea

First, you explain with your in-depth knowledge as an experienced (real-world ?) pilot what precisely the heading is that you'd like see on the 2B2 Plum Island windsocks (to multiple decimal places... FSX can distinguish up to 13 decimal places although most folks don't bother with more than 6 or 10). Rolling Eyes

It would be helpful to others besides myself as well if you would be so kind as to make sure the explanation (and rationale) you give can be readily understood by all here, as we do have many who may not be as advanced in their knowledge as you may be, so I'd appreciate your kind consideration with that, if you please. Confused

Next, I'll make you a repositioned set of 2B2 windsocks (the same models that Jon Patch apparently made available to the FS Community via the FS Developer website some time ago... and I'll even make them the size you like WITH night lighting. Exclamation

Then I'll post them here for both you and others to download so we can focus on our respective various ways of enjoying FSX in general and Plum Island in particular. Very Happy

And perhaps Bill Womack can keep doing what many of us are hoping he's doing now... working on Emma Field for FSX (codename: "EmmaX") Wink

Would that be OK with you ? Question

PS: FYI, There have been very few 3rd party Windsocks made as an alternative to the rather ugly but adaptable and functional one available via the internal FS object code.

Such Windsocks, when 3-D modeled may vary in size, shape, position relative to the central datum or reference point of the spatial wire-frame of the model etc.

IIUC, the one we are dealing with here was made by Jon Patch of Vancouver+ renown some time early before he had progressed further in his GMAX modeling skills and release of his latter work; but it's gorgeous !

We all greatly appreciate his contributions to the FS Community as we do those of Holger and Bill Womack too; so of course most of us don't "critique" a freebie when we can get one. Laughing

Although it is usually considered desirable for 3-D scenery objects to be modeled with their "face" at a "3-D World" heading of 0 degrees in GMAX or FSDS, we see a wide variety of resulting orientations and headings for models that we try to remember to correct for when we place and test objects in scenery.

And most of us don't routinely fly with ambient or fixed winds in FS, so now and then an atypical Windsock 3-D model heading will evade the author and Beta testers discovery that can benefit from a quick, simple, re-positioning.

[EDITED]
Oh, almost forgot to mention that until recently, there were few if any utilities that allow placing Windsocks, so FS Developers tend to recycle an existing old XML "Placement" file for scenery objects to manually place Windsocks, and might (like me now and then !) forget to change the prior XML code for the new Windsock model's "3-D World" heading to 0 (or whatever that particular model requires) in order to correctly follow the wind in FS.

Again, unless the Windsock is tested in FS with the wind blowing, one wouldn't see an incorrect XML "3-D World" model heading.

IIRC, the original Windsock placement for 2B2 was a separate BGL from those for placement of library objects, derived from a custom XML file, and it may be that the scenario above is what transpired. Embarassed

This Windsock modification will take very little to do, so I'll look forward to your reply, and hope you'll be happy with the result. Cool

GaryGB

Gender: Joined: 28 Nov 2009 Posts: 3

The question is: Is wind direction setting (in fs weather menu) magnetic or true?

If we assume that it's magnetic, I can't understand why the windsock indication is offset.

That's all.

EDIT: Another screen...

"fake headwind", looking at the windsock. But try to takeoff with this situation, this is not an headwind at all! We have strong left crosswind, that moves the aircraft to the left... because the wind is from 197° MAGNETIC.

Posted: Sat Dec 05, 2009 8:50 pm (No subject)

Hi Ardix:

Fair enough... I'll offer up an alternative placement BGL for the Windsocks tomorrow after I take a look at the current "3-D World" object heading inside the original XML code from the placement BGL supplied with the Plum Island package.

[EDITED]
FYI: I replaced my windsock that shipped with 2B2 shortly after purchase of the Plum Island package, with a "new" version in order to use a night lighted copy of the Windsocks.

My analysis thus far was based on my "own" re-placement of the Windsock object... sorry for not recognizing immediately that the windsock on your installation was the default one which I had not yet tested with a wind blowing. Embarassed

It is indeed clear from your top-down view that there is "around" a 90 degree Windsock placement heading misalignment in the BGL you are using which needs correcting; thanks for "staying the course" to help us get our heads wrapped around the FS wind and windsock issue at Plum Island. Shocked

Any last requests on sizing ? (I made mine slightly larger for improved visibility)

I'll be out and about today, but will attend to this tomorrow (Sunday).

Have a good day ! Cool

GaryGB

Posted: Sun Dec 06, 2009 9:29 pm (No subject)

Hi All:

[EDITED_AGAIN ! ]

NOTE: I have removed the prior "2b2_Windsocks_Mag-Corrected_GGB.bgl" ZIP file, as further edits were required to align the Windsocks more in keeping with the apparent real world photoimagery positions.

Here's 2 modified Windsock placement BGLs for 2B2 Plum Island which should function in compliance with the way that FS itself reports and displays Wind Direction and aircraft position relative to the world... as MAGNETIC, and NOT as TRUE. Idea

I have positioned both sets of Windsocks more in keeping with the "apparent" real world Windsocks (as I visualized them in the photoreal imagery of the Plum Island airport background texture).

"2b2_Windsocks_Mag-Corrected_Original_Day_GGB.BGL" retains the ORIGINAL size, and displays them WITHOUT a night lighted texture

"2b2_Windsocks_Mag-Corrected_Big_Night_GGB.BGL" enlarges them 1.5 X original size, displaying them with a night lighted texture.

The screenie below shows the resulting Windsock display with a 16 kt. Wind Direction of 180 degrees Magnetic set in FSX... at "Dusk".

In the screenie below, my superimposed "GGB" Windsock placements are on the Left; Bill W.'s are on the Right.

This was an interesting scenario of discovery for a subject that has been, IMHO, rather poorly documented in both the real world and FS world.

I did finally find some links that address the way that (most) real world Winds are reported by ATIS and/or ATC to aviators (...or was that "Pilots" ?! Laughing

)

This finding was a bit disconcerting for a number of reasons, as will become clear to those who chase the following list of links and read between the lines.

Some, of course (or was that OFF course ?) may have the opinion such as that seen on one of the websites I visited:

"In aviation, Magnetic Variation should come into play only, as a previous poster inferred, when plotting a course on a VFR aeronautical chart then converting those course lines to magnetic directions or when answering FAA test questions."

Regardless... a few things I found out:

[EDITED]
1.) Real world ATIS and ATC info on Wind Direction may or may not be given as Magnetic (although most airports give Magnetic)... this is reportedly still inconsistent today, and varies between airports. At some airports, since RWY numbers are always labeled with their numbers rounded off to the nearest 10 degree points on the compass, this can increase the risk of a pilot choosing (or being assigned !) a RWY that may not be optimum for a safer landing relative to "wind direction".

This is sometimes referred to as reporting direction using "36 points on the compass".

2.) Airport diagrams on VFR charts are intended to display Magnetic as well as Mag Var and True... some are wrong or incomplete

3.) AFCAD RWYs are intended to be numbered for Magnetic heading... some (many ?) are wrong.

BTW: Even if they were once right, the Magnetic Declination changes at a rate of 2-2.5 arc degrees every hundred years... so AFCADS should have an expiration date ! Razz

For a BIG, detailed chart to do a Mag Var reality check, click this link:

http://upload.wikimedia.org/wikipedia/commons/2/28/Mv-world.jpg

4.) "The magnetic compass in FS receives its variation data from the magdec.bgl file. These values do not coincide with the data shown in AFCAD, FSNav and similar programs. That is because these programs are accessing the airport BGL files, which contain information based on a diferent magnetic north model."

5.) Pilots may forget what settings they are actually using in FS since some FS Utilities such as ActiveSky, FSNav, and others may report Wind as True; GPSs may be set for either Magnetic or True for example.

6.) Winds in FS are based on Magnetic north. "In the real world of aviation, life is a bit more complicated. Surface winds are reported based on Magnetic north and winds aloft are reported based on True north. Thus WCA's are calculated using True Course and the winds aloft reports."

Here's some of the links I chased (...for those who want to learn more):

http://en.wikipedia.org/wiki/Magnetic_declination

http://earthsci.org/education/fieldsk/declin.htm

http://forums.flightsim.com/vbfs/showthread.php?t=64437

http://www2.hifisim.com/node/41

http://www.metacraft.com/VRC/forums/viewtopic.php?t=235

http://flyawaysimulation.com/postt6570.html

http://www.tpub.com/content/aerographer/14269/css/14269_56.htm

http://www.tpub.com/content/aerographer/14269/css/14269_55.htm

http://www.navfltsm.addr.com/basic-nav-plotcourse.htm

http://www.avweb.com/news/avtraining/flight_simulator_x_for_pilots-chapter_13-weather_196384-1.html

This was a particularly interesting Tutorial for plotting a course for a flight along the East coast in the general vicinity of Plum Island... a good read:

http://www.navfltsm.addr.com/basic-nav-plotcourse.htm

Hope this helps; feedback and/or requests for changes of the file posted below (preferably supported by an educational and factual rationale) are welcome.

Happy Flying ! Cool

GaryGB

Posted: Mon Dec 07, 2009 9:50 pm (No subject)

Hi All:

I made a 180 degree goof (...due to the "180 proof" in my beverage ? Embarassed

) in the version I had posted yesterday evening.

But I now have posted above, what I believe to be a correctly oriented version for the 2B2 Windsocks.

One person downloaded a copy of that incorrect file (I don't know if it may have been a Search Engine spider), but I hope whoever it was comes back to get the correct version of the above Windsock placement file.

Happy Flying ! Very Happy

GaryGB

Posted: Mon Dec 07, 2009 10:01 pm (No subject)

Wow !

Posted: Mon Dec 07, 2009 10:10 pm (No subject)

Was that 'Wow' as in: "Wow... 180 proof !!!" ? Laughing

Uhm, would you believe I made it from a trusty old Hungarian recipe... can't remember the name (one of the side effects, I guess !) Mr. Green

Lemme see (please, please !)... I think it was "Visi-" something.

...As in "my vision is failing due to an unanticipated side effect of the fermentation process" ! Razz

GaryGB

Posted: Tue Dec 08, 2009 3:38 am (No subject)

Hi guys,

This thread prompted me to have a close look at the windsock placement file, and indeed it seems that the socks were placed at some other rotation than 0, which is what they should always be at to avoid problems. I've recompiled the socks BGL only, and am attaching it here. Please put it into your Plum Island scenery folder and give it a try. It corrects the problem for me.

thanks,
Bill

Posted: Tue Dec 08, 2009 8:59 am (No subject)

More wow ! Smile

Posted: Tue Dec 08, 2009 7:07 pm (No subject)

Bumped for the recent edits and file changes above in my post dated Fri Dec 04, 2009 1:06 pm Wink

NOTE: I have removed the prior "2b2_Windsocks_Mag-Corrected_GGB.bgl" ZIP file, as further edits were required to align the Windsocks more in keeping with the apparent real world photoimagery positions.

I posted above 2 new modified Windsock placement BGLs for 2B2 Plum Island which should function in compliance with the way that FS itself reports and displays Wind Direction and aircraft position relative to the world... as MAGNETIC, and NOT as TRUE. Idea

I have positioned both sets of Windsocks more in keeping with the "apparent" real world Windsocks (as I visualized them in the photoreal imagery of the Plum Island airport background texture).

"2b2_Windsocks_Mag-Corrected_Original_Day_GGB.BGL" retains the ORIGINAL size, and displays them WITHOUT a night lighted texture

"2b2_Windsocks_Mag-Corrected_Big_Night_GGB.BGL" enlarges them 1.5 X original size, displaying them with a night lighted texture.

BTW: I recall that in prior versions of FS, one was required to place (2) windsocks at an airport in order for them both to function correctly; perhaps this Windsock model used at 2B2 has implemented a workaround inside the MDL file (ex: 1 of 2 objects is "hidden", or FSX fixed this process to allow a single Windsock to work properly).

Regardless, I believe that the "wire frame" model in question is rotated approximately 8.5 degrees from the desired "0" reference point heading in the 3-D World, so that if a heading in XML placement of "0" degrees is used, the object does not precisely follow the FS Wind Direction (always expressed in degrees Magnetic).

And I do recall that a precise "0" degrees XML placement heading had to be used with the default FS windsock object created at run time from obscure object code in order for it to work correctly.

Certainly I'm new to this aspect of FS, and welcome opportunities for better understanding this somewhat mind-bending topic; perhaps Bill Womack and others could offer additional input on this matter ? Rolling Eyes

The reason I ask is, as seen in the screenies below, Windsock placement in Bill's "fixed" BGL appears (in my present understanding of the scenario) as rotated off the desired Mag Heading for Wind Direction by 8.5 degrees. Shocked

Again, the screenies below show the resulting Windsock display with a 16 kt. Wind Direction of 180 degrees Magnetic set in FSX.

And again, in the screenies below, my superimposed "GGB" Windsock placements are on the Left; Bill W.'s are on the Right.

But obviously as my screenies both above and below show, the current placement in Bill W.'s "2b2_Windsocks.bgl" file seems "reasonably" close to a position that would visually alert a pilot to what direction the wind is coming from so they can navigate accordingly on a VFR approach and landing.

FYI: It has been my goal here to help others as well as myself to better comprehend the best practices for both flying in and out of 2B2, as well as for Windsock placement in scenery development. Idea

I would appreciate any and all feedback from others here, to be sure we now have a correct and final set of 2B2 Windsock files posted for ongoing use, and archival safekeeping.

Thanks... and Happy Flying ! Cool

GaryGB