Page 1 of 2

Winds

PostPosted: Tue Sep 19, 2006 7:01 pm
by elite marksman
Is there any way, to get the winds at altitude, other than Shift-Z? I'm tired of guessing and, normally, being wrong. Now that I actually understand vectors (junior in high school, taking physics) I would be able to calculate the angle of correction in advance, and save myself the "Noble XXXX Turn right heading 110," or worse, in a single seat prop over the ocean, making landfall a hundred miles off course, or even worse, aiming for an island and not hitting it, due to winds.

As far as I know, ATIS and AWIS only give wind vectors at ground level, not at altitude.

EDIT- I really cant spell tonight

Re: Winds

PostPosted: Tue Sep 19, 2006 8:08 pm
by Brett_Henderson
I've seen a few gauges that display the wind vector (direction and velocity) in FS9.

The Garmin 430 in the Cardinal I fly for real has a wind vector calculating function.. But I've rarely used it, because it takes too

Re: Winds

PostPosted: Tue Sep 19, 2006 9:44 pm
by garymbuska
Active sky has a great built in weather radar that not only shows the weather ahead but displays the winds as well.
This is not a gauge but a small program that like FSNAV all you have to do is press CTRL & F12. You have the ablity to load a flight plan into it and it will dispaly the weather at the station closest to your waypoints. I know this is payware but trust me it will be the best money you ever spent. And to top it off I just read a article in avsim that Active Sky got top honors for the best comerical other at the 2006 avsim conferance.
If you want to read the list of awards just got to www.avsim.com

Re: Winds

PostPosted: Tue Sep 19, 2006 9:51 pm
by Nav
Coincidence - last night I was doing exactly that, 'flying' my De Havilland Dove 1,100nms. or so from St. John's, Newfoundland to Flores in the Azores, and not allowing myself any help from the GPS because it wouldn't be 'period'!

elite marksman, over land you'll find that 'dead reckoning' (making a rough allowance for wind and then checking it by mapreading) is good enough; and pretty satisfying. You might like to try the 'Frontier Airlines' scenario in Historical Flights one day, that actually puts you in a DC3 Dakota following roads and railways through passes in the Rockies!

Over ocean, I make sure to start and finish at VORs whenever possible, which takes care of the first and last 200 miles of a given trip - and then trust to dead reckoning for the rest.  

About finding islands without navaids, there actually IS a way - which was used by the old-time navigators. They could always be pretty sure of their latitude from sun-sights, and they used simply to sail along the latitude of a given island or port until they reached it.

That method was also used by Francis Chichester when he flew a Gipsy Moth from New Zealand to Australia in 1931. His life depended on finding Norfolk and Lord Howe Islands to refuel. He actually 'navigated backwards' - 'entered up a given position on his sextant and then flew the aeroplane about taking sights till his position matched the settings!

I once 're-enacted' his flight in a Tiger Moth, deliberately aiming to the east of each island and then turning west along the line of its latitude. I allowed myself a check of latitude ('Shift-Z') every fifteen minutes or so (about 15 miles in the Moth). Found both islands OK, after some genuine suspense!

Re: Winds

PostPosted: Wed Sep 20, 2006 3:26 pm
by vololiberista
I downloaded real stars the other night so now I can not only do dead reckoning or INS but navigate by the stars!!!!!!
Vololiberista

Re: Winds

PostPosted: Wed Sep 20, 2006 4:01 pm
by Nexus
Do you know how to do celestial navigation?
That's an art soon to be extinct  8)

Re: Winds

PostPosted: Wed Sep 20, 2006 4:47 pm
by vololiberista
Do you know how to do celestial navigation?
That's an art soon to be extinct  8)


I know the basics of it and it is very simple (just as is finding north in the desert without a compass)

north is indicated by the Pole Star, which travels in a tight circle above the North Pole and the three stars of Orion's belt light up the Equator. The belt also points east as Orion rises and sets in the sky.

Navigators calculated how far north of the equator they were by measuring the altitude (height measured as an angle) of the Pole Star from the visible horizon. A measurement of altitude could then be converted into their latitude position.

For example:

   * If the Pole Star is on the horizon, the ship is at the Equator (0

Re: Winds

PostPosted: Wed Sep 20, 2006 7:18 pm
by elite marksman
Yes, I know the winds will change, but error can be minimized since the changes will not often be significant (10* error leaves only 18 miles off course per 100 miles flown), and by checking a wind map, since the weather systems that cause upper level winds are relatively predictable.

Re: Winds

PostPosted: Thu Sep 21, 2006 12:27 am
by vololiberista
Yes, I know the winds will change, but error can be minimized since the changes will not often be significant (10* error leaves only 18 miles off course per 100 miles flown), and by checking a wind map, since the weather systems that cause upper level winds are relatively predictable.


"Only" 18 miles of course!!!! If you were flying to the Azores that means you would get quite wet!!!!!!!!!
Vololiberista

Re: Winds

PostPosted: Fri Sep 22, 2006 1:59 pm
by elite marksman
One would fly to the azores in good weather, and so be able to see the islands.  ;D One of the islands also have a NAVAID, iirc.

Re: Winds

PostPosted: Fri Sep 22, 2006 2:57 pm
by vololiberista
One would fly to the azores in good weather, and so be able to see the islands.  ;D One of the islands also have a NAVAID, iirc.


Admitedly Air France oops  Air Chance chose the Azores as the place for one of many (at least 6) crashes of their Constellations also losing two famous personages in the process.
In those days navigation was a mixture of dead reckoning, star navigation, and when in range navigation by NDB. And if weather permitted many transatlantic crossings via the Azores or via Newfoundland were at least in part in the dark if not completely.
Unless the air is Gin clear one wouldn't be able to navigate by sight to the Azores (even then only from 50-60 nm!!!)  Download the L049 Connie and set up a dead reckoning flight  to Santa Maria from le Bourget. When in range use a radio facility as an NDB (not as a VOR or ILS) Plan the descent yourself (ie don't use ATC) Set up inclement weather for most of the flight. remember that even though the Connie was pressurised its ceiling was 22000ft your FL would be about FL160 or 180. So you would be flying through the s h (one) t. Let us know if you land safely  ;D
Vololiberista

Re: Winds

PostPosted: Fri Sep 22, 2006 4:46 pm
by elite marksman
Sounds like a fun flight, but I dont have the patience to do it. :'( I spent from 10:30 to 1:30 last night writing 2 essays that were due today. Both were handed in on time, but im dead today. Thank God its a Friday and I can sleep in tomorrow.

If you think I learned a lesson about procrastination, you are wrong. :P

Re: Winds

PostPosted: Sun Sep 24, 2006 8:02 am
by Nav
elite marksman, even in the pre-GPS days navigators could get a rough idea of wind strength/direction over water (in daylight anyway) by use of a drift-meter - which was a scope with a ground-glass screen, so arranged that you could look straight down and line the grid-markings up with the whitecaps. Took more skill than I possessed to get it right, but experienced people could make it work.

So I reckon that it's permissible, without 'stepping out of period', to use 'Shift-Z' at intervals to get wind strength/direction. After that, as voloberista suggests, be careful not to under-estimate the wind's effect on your course. If the wind's squarely abeam, I'd recommend allowing 3 degrees per ten knots of wind strength. Sounds a lot, but it's roughly right.

About VOR navigation, there's a great true-life story about its origins, for anyone interested. During WW2, about 1942, British Intelligence discovered that the Germans had set up fans of radio beams from Northern Spain and Western France to help U-boats navigate their way in and out of the Bay of Biscay.

When Prof. Jones, the legendary Head of Air Intelligence, heard about this, he immediately realised that RAF Coastal Command were flying patrols in the same area in all sorts of weather, trying to catch said U-boats, and losing a lot of people in so doing.

So he rang them up and asked them if they could use a bad-weather navigation system consisting of intersecting radio beams. Their reply was, "By God we could, answer to our bloody prayers, how soon can you set it up?" Being honest, he had to explain that the Germans had already done it for them, rather than claim the credit for himself.  ;)

So instead of bombing the daylights out of the German beam stations, as they would normally have done, the RAF just developed the necessary receivers and made effective use of the excellent German navaid system for the rest of the War.

Re: Winds

PostPosted: Sun Sep 24, 2006 5:13 pm
by vololiberista
As we're talking history Nav, My father was part of the team that developed radar which initially had spikes on a screen showing the targets. My Father developed the necessary electronics to create the sweeping round screen that we are all familiar with today!!!!!
Vololiberista

Re: Winds

PostPosted: Sun Sep 24, 2006 7:35 pm
by ashaman
This thread is a gem. It's always a pleasure for me to have confirmed the fact that I don't know everything and it's even a greater pleasure for me to learn. :)

2.30 in the morning and tomorrow have to get up, and yet I'm reading all these informations you dish out with an interest that bypasses sleepiness. :)

A question for you Volo. There's a curiosity I have. You say your father was part of the team that developed the electronics that gave us the sweeping round screen we all know, yet sometimes in movies or documentaries of the times it's shown a radar operator that reads the spike(s) on the oscilloscope...

While doing so I can understand how he got the distance of the enemy, it was never shown and I never got on my own how could he understand where around him said enemy was? Was there a switchable set of frequencies to show on the oscilloscope so to narrow down the direction said enemy was? Did he command the direction of the sweep with a knob to be able to say the vector of incoming enemies? Whatever else?

I've reasoned quite a lot about it, another lot I've sought on the net. I'm still answerless and searching. If you can answer, let me know. ;)