A Secondary Saga Southbound Sextant Adventure .. "Seeking Sally"

sorry all, we'll post in the morning...........found an error in the sequence and not really satisfied with the format.......

no sense in buggering it up now...the cranium is shutting down. :sleep:
 
Please Read and follow:
Orientation Exercise:
1. Go to SASA, RW 19, our departure airport, for this adventure

2. Settings to start: Time 11:55 UTC or 7:55AM local time

The sextant setting for our first LOP will be our starting location:
Set the following into the sextant by using the + and – hot spots under Assumed Position. It may take some getting used to, but once you have gotten the concept of entering degrees and minutes, it will become easy after a few times.

3. Set into the sextant under ASSUMED POSITION:

The location of SASA (Aircraft) (LOP)
LAT/ DEG= -24 and MIN= -50
LON/ DEG= -65 and MIN= -30

4. Go to:
http://aa.usno.navy.mil/data/docs/celnavtable.php
Set the coordinates S24° 50.0’, W65° 30.0’ and the time as Aug 6, 2011 Hour: 12, Minute: 0, and Second: 00 UT then Get Data chart.

View attachment 45093

On the data chart notice that the sun’s Zn (azimuth) is 64.6°.

The sun’s Hc (elevation above the horizon) is +12° 39.3’.

5. Set into the sextant under STAR:

The location of SUN’s Zenith at this time.
Set AZIMUTH: 65° (note that we do not use minute settings in the sextant for AZIMUTH settings)
Set ELEVATION: 12° 40’ (which rounded off the closest 5 minutes)
Use the Course and Fine Elevation adjustment wheels, located to the right of the eye piece on the sextant to set the elevation. Once again, it may take some getting used to setting these in, but once you’ve gotten the concept of entering degrees and minutes, it will be simple.
Before taking a reading, set the bubble wheel, located on the left side of the eye piece, to Size 3.

We’re now ready to take our first shot of the sun: (For the best accuracy, always start the shot exactly 1 minute before the data chart time): In this case start the shot at 7:59:00 AM local time.


6. Double Click on the eye piece and let the bubble dance for one minute
until it goes out (No need to move the Fine adjustment wheel while we are here at SASA) Once the shot has completed notice that, under DISTANCE N. MILES, the result is 0. Now, at the top left of the graph click on the Star 1 hot spot and there will appear a slanted blue crossing directly over the small green circle (our location is the center of the graph). This is telling us that we are where we are.


View attachment 45092

Now that we know how to navigate around the settings and how to take a reading, let’s make some sense of it all.

Without changing our ASSUMMED POSITION


7. Set AZIMUTH to either 0° (360°) or 180°
and take a reading then hit the Star 2 hot spot. Notice we now have a straight horizontal green line across the graph, no matter which azimuth we chose. (Directly North or South)


8. Next set AZIMUTH to 90° or 270°
and take a reading then hit the Star 3 hot spot. Notice we now have a straight vertical red line across the graph, no matter which one you chose. (Directly East or West)


The graph should look exactly like this.

View attachment 45095

You can turn off the lines on the graph by hitting the Star 1, 2 and 3 hot spots.


9. MOVE the AIRCRAFT to SANT

Repeat steps 7 and 8 but this time, by using the fine adjustment wheel on the right, center the dancing bubble into the circle.

The graph should look exactly like this.

View attachment 45094

You can turn off the lines on the graph by hitting the Star 1, 2 and 3 hot spots.


10 . MOVE the AIRCRAFT back to SASA


Logic: As we all know, the sun comes up in the east (approximately) and sets in the west (approximately). So during the course of the day in the morning the sun will be somewhere in the eastern half of the compass (Zn) until noon and in the afternoon and evening the azimuth of the sun will be on the west side of the compass (Zn)…..thus represented by the red line (exactly east) and the blue (approximately east). So the blue and red (vertical lines) are east and west readings. That is how the graph is oriented and we can look at it as reading LONGITUDE.

The horizontal green line is the LATITUDE reading (north and south).
Of course every star or the sun reading will NOT be located exactly north south east or west, which is illustrated by the blue line which is oriented diagonally across the graph.

To sum it up simply: We now know that the horizontal lines on the graph represent latitude and the vertical lines represent longitude.


All this may not make sense at this time, but keep in mind that the that little green circle in the center of the graph is the ASSUMED POSITION of the our aircraft’s LOP, which is located at SASA. By moving the latitude or longitude under ASSUMED POSITION a couple of degrees one way or the other will give us an ASSUMED POSITION of the aircraft LOP AWAY from the present location. For each degree we move the latitude it will represent 60nm away from the aircraft. For each degree of latitude, read here at S24°50’ a degrees of longitude is about 54nm since the longitudinal lines are getting closer as we move toward the pole from the equator. We can try different settings to get the idea if you’d like at this time. We’ll need to move the elevation to center the bubble in the bubble circle while taking the reading if we do this.

NOTE: Think of looking at the stars as if we were inside a planetarium (dome) and the stars were on the ceiling of the dome. If we were standing looking straight up at a star, at that moment in time we would be at that star’s Zenith. Or if we were to draw a line from a star straight down to the earth that point on earth is at that star’s zenith. Enough of this…….Orientation is over.
Perhaps you’ve noticed something here by now? We were not actually looking at the sun when taking readings were we? However a star was visible each time we took a reading. So, by this time, you have probably realized that we don’t really NEED to use the charts in FS to navigate. We can get latitude and longitude readings anytime night or day. Of course there are many ways to cheat in FS using map followers, when flying using Guenna, and other means such as the GPS, looking at map view, etc.

As always, the idea for these flights here is to do it honestly.
J


END ORIENTATION

 
SASA to FIX # 1 LOP

Start of the Antarctica Adventure


We’ll try to avoid using Shift Z at all costs when flying, but you may use it to compare the settings, explained below, before takeoff.


First we can check the weather, especially the winds aloft, at various altitudes.

In case you don’t know how to do this in FS, here is my method.

Go to Weather/User Defined/Specific Weather Station/Choose Station./Salta, Salta, Argentina….retrieve the weather then choose the Wind Tab and click on the various yellows lines up to 18,000 to get the existing winds aloft conditions. You can now return to weather updated every 15 minutes. At least we know what it’s doing now. Better info than the navigator pioneers had used the sextant. You’ll find that by using the sextant, we can check our TAS or TGS by taking exact timed readings.


First leg: SASA-SAME (NO WEATHER THIS TIME> Set to clear all weather). When setting up a flight plan in Plan G I set in a fixed point between the two airports at S29° 30’ and W67° 21’ LOP reference. Each leg shows a heading of 198 degrees. This is a slightly off the great circle route, but the difference isn’t that critical when navigating using the sextant.

View attachment 45114

1. Settings to start: Time 11:55 UTC or 7:55AM local time for an 8:00AM TO.

The sextant setting for our first LOP will be our starting location:


2. Make sure that the ASSUMMED POSITION of SASA’s LOP



3. OK were ready to go. Again if graph is not cleared, turn the lines off on the graph by hitting the Star 1, 2 an 3 hot spots and let’s be on our way.


We’re going to start rolling and take off on the RW at exactly 11:59:30Z or 8:59:30 local time or close. This is not critical, but we realize some folks are perfectionists. I guess, once the wheels leave the ground we’re flying. Is that a reasonable thing to assume? I believe that’s when Duenna time begins. Also, on the RR_41 DC-3, I’m going to start the stop watch when at rotate.


Our course will be set to a heading of about 197 or 198°. We’ll climb and use the 17,000’ ceiling on this leg. The default load will be OK this time, we’ll pick up out produce or whatever supplies for Antarctica later. For those who may be flying the DC-3 RR_41, 1940 edition, be sure to keep the CHT below 323C.



4. Go to:
http://aa.usno.navy.mil/data/docs/celnavtable.php
Set in the same coordinates and time of Aug 6, 2011 hour=12, minutes=30, and seconds=0 UT
We’ll take a sun shot when the clock or stop watch reads 8:29AM local time. We’ll leave our ASSUMED LOP at: LAT/ DEG= -24 and MIN= -50 and LON/ DEG= -65 and MIN= -30…….SASA

ON the sextant, set the AZIMUTH to 61° and the ELEVATION to 18° 40’ as read from the charts and we’ll now be ready to take our first LOP shot.


Our first LOP shot will be a reading behind us at SASA.

Notice the sun’s Hc (elevation above the horizon) WILL BE +18 degrees and 42.1 minutes. (Note that at that time the sun is above +15 degrees above the horizon. So in the real world it would be a good shot.
View attachment 45115
We’ve traveled 50nm in 30 minutes at an average ground speed (GS) of R= D*T or 50*60/30=100nmph for the climb out and 1[SUP]st[/SUP] half hour.

5. Next we’ll change our NEW ASSUMED POSITION LOP to FIX # 1, which is S29° 30’ W67° 21’

On the sextant below “ASSUMED POSITION” set:
LAT/ DEG= -30 and MIN= -30
LON/ DEG= -67 and MIN= -20

Again we’ll set at the USNO site: Go to: http://aa.usno.navy.mil/data/docs/celnavtable.php

Set in the NEW coordinates and change the time to Aug 6, 2011 hour=13, minutes=0, and seconds=0 UT

South 29° 30’ and West 67° 30 min then Get Data tables.

This will give us the position of the sun in the future, or in one hour after take-off. Notice that at this time the sun’s Zn (azimuth) will be
55.7 ° and the suns Hc (elevation above the horizon) will be +29° 30.9’


SET IN under STAR:

Location of SUN’s Zenith at this time.

Set these readings into the sextant’s AZIMUTH 56° and ELEVATION DEG= 20 and MIN= 30 using the Course and Fine adjustments on the right side of the sextant’s eye piece.

Now we’re ready to take our second reading at 1300 UTC or 9:00 AM local time. Notice the sun is up to 20 degrees above the horizon so there the atmospheric refraction will not affect our readings. (not that it would in FS, just to make it clear if you were doing this in real life)

Hmm, looks like we’re going to need to do some ridge dodging as well.

View attachment 45116
Notice where the blue line and the horizontal lines cross at 120nm on the graph. Also note the once you record the distance on the graph, the DICTANCE N. MILES reading changes. I don’t know why, but this happens….with the sextant and graph gauge.
We’ve traveled 70nm in this 30minutes at cruise so our average speed GS has been R= D*T or 70*60/30=140nmph at cruise speed. We should be over the FIX #1 at about (120/140)*60=51.4minutes or at 9:51AM local.

We’ll take another shot in 25.4 minutes at or 9:25:45 (1 minute before we should be AT 60nm for Fix #1).



6. Again Go to:
http://aa.usno.navy.mil/data/docs/celnavtable.php and set the time for the sun readings and set them into AZIMUTH and ELEATION. For 51° and 24°55’ respectfully as read on the data chart.
SET IN under STAR:
Location of SUN’s Zenith at this time.

By now I’d be willing to bet we have several sextant pros!!!!
J

View attachment 45118
Shot taken at 25.4 minutes at or 9:25:45 (1 minute before we should be AT 60nm for Fix #1). The Green line shows us that we're traveled another 60nm which was our projected time and distance in 25 3/4 minutes.



7. Again Go to:
http://aa.usno.navy.mil/data/docs/celnavtable.php and set the time for the sun readings and set them into AZIMUTH and ELEATION at For 46° and 29°10’ respectfully as read on the data chart.
Start the shot at 9:50:15 (again 1 minute before reading time)
View attachment 45119
Bubble is looking good!!!!! (This is a shot of the bubble before the reading).

One minutes has passed.

View attachment 45120
Wala! We've reached Fix #1 LOP right on time! :running:
:applause:

The next post will be from Fix#1 to SAME

dil
 
Flight from SASA-SAME continued from Fix#1 to SAME.

Next we’re going to set the coordinates for SAME, which, according to our calculations is located at:

On the sextant below “ASSUMED POSITION” set:
LAT/ DEG= -32 and MIN= -50’
LON/ DEG= -68 and MIN= -50’


While writing here I’d run out of fuel in the Mains and discovered I’d lost 2000' so this is going to take a toll on our average speed……or should I say mine.
J

At this time we should change our heading about 10 degrees or so to one side or the other of SAME. We need to do this because we don’t really have an accurate way of determining latitude and longitude without a two or three star reading. We only have the sun.


8. Again Go to:
http://aa.usno.navy.mil/data/docs/celnavtable.php and set the time for the sun readings and set them into AZIMUTH and ELEATION. For 46° and 29°10’ respectfully as read .

We’re going to set in the time as 14:30:00 at the UNSO site.

(Anyone can feel free to take as many shots as they may desire now) Don’t forget to set in the coordinates for SAME before GET DATA
Also make sure to have an accurate Zn and Hc for each time a reading is taken!


View attachment 45127
Notice that the AZIMUTH of the sun is on 37° (and behind us in the souther hemisphere), which is less than 40° from "noon" which would be a Zn 0 or 360° giving us more of the latitudinal reading than longitudinal accruacty. For this reason we're going to rely more on the horizontal lines of the graph thanvertical lines. Looks like about 75 nm to SAME LOP.

9. At about 60 nm we’re going to start a slowly descent down to where we can get a visual once we turn 90 degrees onto our LOP. In this case since I turned to 188 degrees I believe we’ll be east of SAME so we’ll turn right to heading 278 or 198+90 degrees to the airport.

View attachment 45128

Found out that if we resize the screen, while flying we loose all our settings in the sextant. Thus we had tor reset the ASSUMMED POSITION and STAR in the sextant. thus the lost prior reading. Not important just to let everyone know why we have only one LOP line after the 2nd SAME LOP reading.
Again writing while flying has got me. I’d forgotten to start a descent at 60nm, so we’re heading down now at 25 LOP. We learn from our mistakes. We’re not doing this flight over. What we see is what we have got.
icon26.gif



View attachment 45129
8. LOP 5nm....It's time to turn right 90 degrees to heading 278° and begin searching for the airport. We'd turned 10 degrees left back about 70nm out, which gave us a right turn once the LOP was reached. If anyone turned more left to intentually MISS on one side of SAME then they should turn right one the LOP is reached. Stands to reason.

I had a nice shot when we first got the airport and accidently deleted it.
I'm sure we'll get some great shots from others who make this flight.


After a procedure turn to loose altitude we located the airport once again and landed sucessfully.

View attachment 45130
Final approach to Mendosa, Argentina SAME.

This completes the first leg to Antarctica. We’ll keep this detailed flight for reference. There’s no need to post subsequent flights with such detail and screen shots. Everyone who’s completed this flight will have a good idea how the sextant works.

The challenges from here on out will increase as we’ll use real world weather on the next legs..

Please join us all who can!!!:wiggle:

dil
 
What a wonderful job Dil!!


A tremendous effort very well laid out.




Now take a well deserved break and let the rest of us blokes follow along.


See what sort(s) of questions come up.




Thanks Man!! ... this is terrific!
 
Thanks salt

We decided to give it a try with Duenna so we used the weather. Once we acquired we saw that the winds aloft were from 256° at 30 knots at 18,000'. With a little E6-B calculations we figured that at a 100knot climb we'd slowly increase the WCA to 12 degrees or from 197 to 209. Once we reached cruise speed we decreased the WCA 9 degrees WCA.


Settings for DC-3 RR41 1940s edition.
Aircraft gross weight: 23806.9 lbs
Fuel weight: 2401.9 lbs
Departure: FS Time: 04/08/2011 07:59:468:00AM

Landing:
System Time UTC: 04/08/2011 19:36:10
FS Time: 04/08/2011 10:52:43
Aircraft gross weight: 22202.3 lbs (-1604.6 lbs)
Fuel weight: 797.3 lbs (-1604.6 lbs)
Location: S 32* 49.671' / W 68* 47.612'
Airport: SAME 0.6nm
Valid: VALIDATEDrrival:

We seemed to have made much better time this flight, the WCA seemed right although a bit of gyro drift, and WCA put us about 10nm east of SAME LOP, which is not bad at all for the sextant.

Here are some screens and the Duenna map.

Sorry I accidently closed Duenna before attaching the map and text file.


.....I just notice they're included in the flight map link...sweet!

Another fantastic SOH feature!


http://fs-duenna.com/flights/ShowFlight.php?detail=flight&value=5gNB2vIeKWKkAVWoRD9FJdiXoI

The screen shots should be in correct sequence.

View attachment 45209
8:30AM 55nm from SASA

View attachment 45208
Green line 9:00AM 90m to Fix#1 LOP

View attachment 45207
Red line 9:19AM 50nm to Fix#1 LOP

View attachment 45206
Blue line 9:37AM 5 miles past Fix #1 LOP

View attachment 45213
Blue line 140nm to SAME LOP

View attachment 45212
Green line 50nm to SAME LOP begin descent

View attachment 45211
On SAME LOP Heading 287 degees

View attachment 45210
Field in site on left

Sorry I can't fly on Saturday morning, but will be available to answer questions Saturday night and Sunday.....and beyond.

I hope you enjoy the fight as much as I have

It was much more enjoyable just flying and taking readings without needing to document and write.
icon26.gif


dil :wavey:
 
Thanks Gutner,

I'd rather be lucky as they say! The 30 kt cross wind is just a breeze up here in the S30's latitude.

Once we reach the Roaring Forties, Furious Fifties, and Screaming Sixties, the crosswinds are going to get tough.

Cape Horn is noted for the worst winds in the world, because there's very little landmass to break them up as exists in the northern hemisphere.

This is the kind of flying that Carmen, my very lovely copilot, cut here teeth on, since she's from down around these parts. She can't wait to get back to the Horn. Hmmm...?

I over heard a conversation down at the local watering hole that her "claim to fame" is skinny dippin at the Horn every time she gets back down there. It's a tradition or something like that. Who knows, you can only believe about half of what you hear when folks are full of stout.:guinness:
icon26.gif
icon26.gif
icon6.png
:kilroy: We'll just have to wait and see!! There's no way I'm going to bring up the subject to her.

You should give this a go......no sense using the weather until you're comfortable with it. By the time we reach the S50's there'll be others leading the flights......

I'm sure of it.

dil
 
This is it! ... cputters

We are in no hurry at all ... give it a whack and ask questions just like the rest of us mate ... you'll be in good company!


Do you need any help getting the sextant in the plane you want to use?

Ok, I might give this a crack.

Ok, found it. Lets see how this goes shall we?

edit: I'm getting a cross reference to gauges, so it isn't just the sextant I have up in this window. Also, after taking my 1 min reading, there was no graph. Other than that it works fine though.

Any suggestions?

Thanks
 
Ok, I might give this a crack.

Ok, found it. Lets see how this goes shall we?

edit: I'm getting a cross reference to gauges, so it isn't just the sextant I have up in this window. Also, after taking my 1 min reading, there was no graph. Other than that it works fine though.

Any suggestions?

Thanks

Yeah ... could you open your panel. cfg in notepad and take a screen shot to post?


Better yet is to make a copy (to desktop) of the Panel.cfg and change the (rename) the cfg to txt ... answer yes ... and attach the new copy txt file to a post.


Copy not cut!


Should be able to get rid of the conflict and get the chart working no worries.
 
Thanks Dil ...

Things look great, just need some time to catch up .... should be on board soon.




Handy with the E6-B too I see ... good show mate!
 
edit: I'm getting a cross reference to gauges, so it isn't just the sextant I have up in this window. Also, after taking my 1 min reading, there was no graph. Other than that it works fine though.

Any suggestions?

Thanks

cputters,

It'll be great to have you along. :applause:

You need two sextant file downloads, the BB3 (the original sextant) and the BBsx, which adds the graph.

Depending on the aircraft you're using you can add an the icon as well. In the DC-3 RR41 as you see in the pics my sextant icon is located here in the panel cfg.

gauge60=BB_sextant!icon, 16,725,19,19

That locates it on the far left of the top row.
If you have any more questions salt_air will get hooked up, I'm sure of that.

salt_air,

Don't worry about catching up, we have plenty of time. Mendoza has a lot of tourist attractions.

We're going to visit a ranch and see these Argetinian cowboys (gauchos) use one of those funny looking lassos called a boleodoras.

Edit: Also, Gunter is still in La Paz on the cargo haul, so it'll be awhile until he reaches Salta.

dil

 
Edit: Also, Gunter is still in La Paz on the cargo haul, so it'll be awhile until he reaches Salta.
Hey Dil,
don't wait for me!
I won't have any time to fly to Antarctica, however much as I'd like to.
Currently pushing along to Salta to finish before vacations, but once there, I've got tons of other urgent stuff to do.
I'll watch from the jump seat.
Gunter
 
While I'm flippin' and floppin' around in the "Deep End" .... is there a way to see if the moon is visible and if so maybe some fixes as well as LOP's ....


We can do that later if you want ... don't mean to ring the rag out ... just enthused.


Screen shot of the plane as I prepare time tables and charts for my first attempt.



View attachment 45295
 
Here's a new panel file in notepad as a txt .... just download or copy and change (rename) the extension to cfg.

View attachment 45381



Drop it in your panel folder and let it overwrite what you have now.

It is complete for both downloads ... just need to make sure have placed the cab file from the bbsxa.zip folder (dc3_bbsxa/BB_sextant4.cab) in your fs9 main gauges folder.

This will clear up the double assignment and call up the sextant w/chart by the simicon on the panel.

No more GPS ... the sextant has taken it's place.

If after a few tries you want the GPS back, then hollar again and I'll be happy to do a quick fix for that.

You can always go to the map if you get completely lost instead of the GPS, but that's your call and like I said if you want the GPS back .... in addition to the sextant let me know ... no worries.







Cheers,
 
The Moon and it's Phases

Hi Salt,
Good question about the moon.

In FS the rise and set times of the sun moon and stars are accurate even to this day, because the calculations are definitive and linear and are accurate for hundreds of years in the future.

The problem arises with the phases of the moon. They still exist in FS9 and FSX however the phases of the moon are variable and need to be calculated differently all the time. For that reason a program required to calculate the phases of the moon for years in the future would have been huge so MS didn’t do it. The phases were accurate back sometime in 2003 when FS2004 was programmed, but have slowly gotten out of sync though the years.
Depending on which version of FS you’re flying the moon’s phases will be different, since they were originally programed in different years. FSX is still a bit closer to being correct than FS9; however in a few years the future it will gradually get out of sync as well. I'm sure it's already happened, just fewer days out of sync than FS9.
I believe, if I remember correctly, that FS9's phases will be correct again sometime in 2020 or so. I may be wrong, I'm just going from memory, which gets me in trouble every time. :)
Someone is going to take the time to figure that out, I'm sure. :)


The rise and set times of the moon are also available on theUSNO site here.
http://aa.usno.navy.mil/data/docs/RS_OneYear.php
So for Salta, we enter the coordinates, and use 4 hours west of Greenwich for the time zone.
This gives us the rise and set times of the moon for a wholeyear. (local time)

Since FS2004 was programmed the phases of the moon are about 10 days out of sync now, Again I'm not positve, but I know that's pretty close.


By going to this page here in the USNO site,
http://aa.usno.navy.mil/data/docs/MoonPhase.php we see that the full moon for this month is August 13[SUP]th[/SUP] at 13 57 UT

Here is a shot in FS9 on August 13th, 19:00 local time at Salta, Argentina.

View attachment 45385

As you can see, in FS9, the Moon only a cresent at this time in August when it will actually be Full.

I don't know if anyone has ever noticed it, but I've actually seen the phase of the moon change while flying at night. That's pretty awesome IMO.

We can get into trouble is when we go outside an see the moon, then go to FS and we don’t see it. The reason could be that there’s a New Moon in FS but not in the real world. The New Moon phase is not visible in FS.

Now, to answer your question.
icon26.gif


The flight starts at 8:00AM Salta local time and is about 3 hours in lengh. Notice that, on August 6th, the rise and set time of the Moon is 1138 and 0022 respectfully. So we wouldn't see it during this flight and probably not until dark, although there are times we can see the moon in day light hours in FS it is rare.

I hope this helps

dil
 
Thanks a lot Salt

I will be keeping the GPS because I'm using the same aircraft for my RTW antics. (Teaching myself instrument operation as we go. :) )

Anywho, it should just be a matter of changing the window the sextant appears in rather than replacing the GPS?

Then adding a description of the new window at the start of the file.?

I'll hopefully go for my test flight tonight.

Chris
 
Thanks a lot Salt

I will be keeping the GPS because I'm using the same aircraft for my RTW antics. (Teaching myself instrument operation as we go. :) )

Anywho, it should just be a matter of changing the window the sextant appears in rather than replacing the GPS?

Then adding a description of the new window at the start of the file.?

I'll hopefully go for my test flight tonight.

Chris








Very well then Chris .... this is what you'll want to use instead of my first offering.


View attachment 45419


Same directions ... you'll have the sextant in working order with no conflicts AND a GPS with it's own simicon on the panel.



Happy Days!
 
Back
Top