Stuck with Nav

[inmyth]

Hey,

I've got a Nav exam in - oh, 12 hours (yes, no sleep for me tonight...) - and I can't actually read the 1:500 000 map to save my life. I've also packed away my Navigation and Meteorology PPL book and it's somewhere at the bottom of some cardboard box. Point being, I'm doomed.

Can anyone please help me out? All I want to know is that when you get this in the question: N5051.57 W00045.55 what exactly does it mean? I used googlemaps to find the place (Chichester/Goodwood) but don't really see how the numbers correspond to the actual position of the airfield :sad:.

So please help me?

[slam525i]

Perhaps you can clarify the question?

N5051.57 W00045.55 =
North 50 degrees, 51.57 minutes
West 000 degrees, 45.55 minutes.

It's an airfield near Goodwood like you said. you can even see a Cessna on 14!

[BackPacker]

I wish they would standardize the notation all throughout the world and througout all applications.

Here are the three most common ways of writing things down, and their abbreviations:

Method one: Degrees and decimals of degrees. I don't have the degree sign here, will use a * for that: N 50.8595* W 0.7591*. The * is usually left out.

Method two, the method used most commonly in aviation, is degrees, minutes and decimals of minutes:

N 50* 51.57' W 0* 45.55'. Leaving out the signs gets you N5051.57 and W00045.55

Method three is degrees, minutes and seconds. The same position as before would be:

N 50* 51' 34" W 0* 45' 33". Leaving out the signs gets you N505134 and W0004533

So look at the location of the decimal point first to see what sort of notation method they use. From there, you can figure out what the numbers mean.

And in Google Earth you can just input whatever method into the search box and "fly" directly to that destination. Google Earth knows all three methods, although you've got to leave spaces between the degrees, minutes and seconds - you can't concatenate the whole lot together like I did above. Unfortunately you can't use GE on the test...

[BackPacker]

With any luck you will get airfields in your local area, I did

I am from the Netherlands and did the CAA PPL exams in Florida. I needed to fly from one UK place to the other on my nav exam and I didn't even have the foggiest idea in which part of the UK those places could possibly be found.

In fact, the nav exam was the very first time I ever laid eyes on the UK ICAO chart. Up till then everything (prep at home and actual flying) was done with either the Jeppessen Low Countries (NL, Be, Lux) or the FAA ones for Florida.

Passed the exam first try though, and didn't even ran out of time. Although I did run out of floor space: at OFT they have these tiny briefing rooms with two chairs and a 60x60cm wall mounted table. They're also used for the theory exams, including nav. You can almost completely unfold the UK ICAO chart on the floor.

[bArt2]

I don't have the degree sign here, will use a * for that

A bit off-topic I guess but for your info, if you hold the "ALT" key and then push "0 1 8 6" it will give you the º sign.

Greetings, Bart

[BackPacker]

A bit off-topic I guess but for your info, if you hold the "ALT" key and then push "0 1 8 6" it will give you the º sign.

No it doesn't. It should have been Ctrl-Shift 00B0 as per ISO14755. Unfortunately PPRuNe overloads the Ctrl-B to insert a "bold" tag so this doesn't work. (Linux+Firefox on a laptop.)

There is a character composer so that I can cut&paste the right characters in but I couldn't be bothered.

[TotalBeginner]

No it doesn't. It should have been Ctrl-Shift 00B0 as per ISO14755. Unfortunately PPRuNe overloads the Ctrl-B to insert a "bold" tag so this doesn't work. (Linux+Firefox on a laptop.)

Works perfectly well for me! ºLº

[18greens]

and on a mac its simply alt-zero 0º. Fantastic, now i've done learning for the day.

[Windy Militant]

Too add to the confusion the grid used on Google maps does not have the same origin as the CAA charts. This caused a certain amount of confusion when we held a fly in at a farm strip recently. I gave the co ordinates from the CAA chart and posted a picture of the strip. I hadn't noticed the discrepancy until I started getting e-mails asking which co ordinates were correct. :confused:
If you haven't got a Pooleys or similar airfield gazetteer try googling Chichester-Goodwood (http://http://ukga.com/airfield/chichester-goodwood)

[bArt2]

Depends what system is used as reference, most used now is WGS-84 (world geodetic system 1984) but there are a lot of others possible. When you have coordinates that use WGS84 reference and plot it on a map with for example ED-50 (European Datum 1950) there will be some position error.

By the way you can change this reference system in your GPS.

Click on the following link for more info on this subject: http://en.wikipedia.org/wiki/World_Geodetic_System

Some more info here: http://home.online.no/~sigurdhu/Deg_formats.htm

Greetings, Bart

[PompeyPaul]

...did you pass ?