PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Aviation History and Nostalgia (https://www.pprune.org/aviation-history-nostalgia-86/)
-   -   How to get wind from drifting? (https://www.pprune.org/aviation-history-nostalgia/598351-how-get-wind-drifting.html)

wildbillkelsoe 15th Aug 2017 08:46

How to get wind from drifting?
 
I am not a real pilot and I just fly on PCs. This is my first thread here, so I hope I chose the right sub-forum.

My question revolves around getting wind direction and magnitude at a fixed cruising altitude from observed drifting.

Scenario:

I takeoff from point A, fly for 25 minutes on indicated heading 200°, altimeter is 4500 feet, indicated airspeed 100 knots, following a radio beacon on heading and expecting first visual fix being a red house at 50 nauticals dead ahead. Now after 30 minutes of flying, I notice that the supposed red house is to my right hand at 2 o'clock, about 3 nautical miles, while radio beacon is solid on the 200° bearing. To make matters worse, an updraft hit my plane and the weather briefing flew out the window (non-existent). Now I need to get this calculated. And look, the cloud base rose up to 4000 feet. Now I can't see anything.



In the back of my head, the red house which was supposed to be on my nose, now is on heading 260° at 3 nm after 30 minutes.

How to do it?

DaveReidUK 15th Aug 2017 12:56

If you haven't done so already, you will find it helps to draw yourself a diagram.

You also need one of those strapped to your knee:

https://i.ebayimg.com/thumbs/images/...nXn/s-l225.jpg

:O

Joking aside, "following a radio beacon on heading" would suggest that you might want to review the difference beetween track and heading.

RAT 5 15th Aug 2017 15:04

Ah; the Dalton computer: or is it? It looks to sophisticated and no where to put the dot with a chinagraph.

sycamore 15th Aug 2017 15:05

R5,lift the lid...

teeteringhead 15th Aug 2017 15:39

One traditional way is the "Manual Air Plot", but you really need another pair of hands (or a Nav!).

Thusly: you plot your heading and TAS on a map, completely ignoring the effects of wind. The theory then says that after a given amount of time (Ideally an hour or easy fraction thereof) you plot the difference between your actual position and the Air Plot position. The difference will be the wind effect.

Which all proves that "Directional Consultants" entire raison d'ętre depends upon the effects of wind.......

DaveReidUK 15th Aug 2017 17:10


Originally Posted by teeteringhead (Post 9862722)
after a given amount of time (Ideally an hour or easy fraction thereof)

Reminds me of when the RAF was looking for a new trainer (the role that the Tucano eventually filled). The RFP specified that the aircraft should be capable of flying at 240 KTAS.

Apparently the RAF can only navigate when flying at multiples of 60 kts. :O

Yellow Sun 15th Aug 2017 18:16


Originally Posted by DaveReidUK (Post 9862808)
Reminds me of when the RAF was looking for a new trainer (the role that the Tucano eventually filled). The RFP specified that the aircraft should be capable of flying at 240 KTAS.

Apparently the RAF can only navigate when flying at multiples of 60 kts. :O

Trouble is, if you wanted to fly 10kts faster you'd have to learn the 1:50 Rule :O

YS

sycamore 15th Aug 2017 18:31

wildbill,as teeters says,do an `airplot `on some graph paper; you should find that,your ground speed is 97 kts,your drift is 3.5 deg. port,as you are left of track,and computing gives a wind of 260/7kts appx. So ,if you are going 100 miles,you need to alter heading 3.5d stbd,to parallel track,then another 3.5 d to regain track at destination,or, 10.5 d stbd to regain track at about the 75 mile mark.Suggest another 50 rpm and you will regain time as well,as you are 1minute late.....
Whilst the `radio beacon may still be showing 200deg. it is probably a class B bearing which was accurate to about +- 5 deg.Dont forget your fuel checks and time log.....

creweite 15th Aug 2017 18:45

Hmmm, ADF, I remember those from years ago when I did my IR rating, but does anyone still use what few have not been decommissioned yet when GPS or even VOR is so superior?

oxenos 15th Aug 2017 21:50


Apparently the RAF can only navigate when flying at multiples of 60 kts.
And all navexes start at 1000 GMT

Rosevidney1 15th Aug 2017 22:15

Multiples of 60 kts? Pah! Luxury! When I trained on the Hiller 12B a lifetime ago we were lucky to get it up to 55kts. It didn't take a great deal of wind on the nose to demonstrably slow our stately progress across the countryside. Conversely a chuff wind might enable keeping up with a motor car!

izod tester 16th Aug 2017 09:25

Of course, if you have a navigator, he used to have a drift recorder like this:
https://www.ion.org/museum/item_view...1&scid=2&iid=3

Herod 16th Aug 2017 12:11

Driftmeter. There is one available on Flight Sim, as well as a virtual E6B. Suggest the original poster search for them.

Blacksheep 16th Aug 2017 12:42

The Lancaster was equipped with the Mk.I izod and from photos of the flight compartment (as we techies call the cockpit these days) of PA474, it still is...

http://www.lancaster-archive.com/pic-lanc-interior6.jpg

It's the thing with the big foam rubber ring round the top [a prime reason for Lancaster navigators being prone to having a fine black eye at the end of a trip.]

Herod 16th Aug 2017 14:55

ref driftmeter for Flight Sim. here is the link. https://www.flightsim.com/vbfs/fslib...ight&fid=99543.

If this doesn't work, log onto flightsim, go to search file, driftmeter. This is for FS9, but I'm pretty sure it woks in FSX

The link above goes directly to the download page. The file name is drift7.zip

Airclues 16th Aug 2017 19:01


ref driftmeter for Flight Sim. here is the link.
I doubt whether wildbillkelsoe will see your reply. Although the above replies are interesting to an aviation historian, I feel that he might have been better asking on the Private Flying forum.

He/she is not accepting private messages so I doubt whether he/she will even see these replies.

Dave

old,not bold 20th Aug 2017 18:18

I seem to remember that the Twin Pioneers based in Sharjah in the '60s were fitted with a simple drift sight very similar to those mentioned so far. And although I don't remember seeing it, the Shackletons would probably have had one too, wouldn't they?

The Twin Pin one was very easy to use; you just rotated the scope tube until the hairlines lined up with the apparent direction of travel over objects on the ground, and then read off the drift angle from a scale. In hazy conditions, though, it was sometimes difficult to see the ground clearly enough. At night, the moon gave enough light if was big enough, and the occasional Bedu camp fire was useful.

Dan Winterland 21st Aug 2017 02:21


Apparently the RAF can only navigate when flying at multiples of 60 kts.
Bulldog 120, Gazelle 120, Tucano 240. JP 240 or 300, Hawk 420. It makes the mental maths very easy. The exception to the rules where the few that were multiples of 30 such as the Chippy and Wessex (90) and the Tucano in the Nav training role - 210. This last one was to allow the aircraft to catch up if it was late. The Tucano could only relay manage about 255 at max chat on the flat.

Rossian 21st Aug 2017 13:40

For the OP.....
 
.....most of the replies suggest you are able to pick out landmarks relative to your track.
Out in the ocean there aren't any landmarks. Thats when you need smoke/flame floats in the water and a drift sight to do the dreaded "three drift wind". Great fun! Not!

The Ancient Mariner

Rosevidney1 21st Aug 2017 20:43

Dan Winterland
Quote:
Apparently the RAF can only navigate when flying at multiples of 60 kts.
Bulldog 120, Gazelle 120,

Interesting. In the AAC we used to cruise at 135 kts and there was an 'intermediate pitch stop' on the collective lever to achieve this. Hadn't heard of the RAF using 120 kt . What speed did the Navy use on their Chicken Legs, I wonder?


All times are GMT. The time now is 02:50.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.