Rule Of Thumb
 

What i would like to know are all those easy to remember tricks we all use to make the work load easier. For a start how about a DME ARC? Turn ten twist ten! Turn ten degrees and twist ten on the VOR, intercept and repeat. Any more people?

WOT IF THERE IS NO VOR like Gloucester?

there was an article in the April edition of "Pilot" magazine titled "Rules of Thumb" with them all listed.

very good article. would be worth getting a back issue.

Whopity,
You wouldnt be asked to do a DME arc without a VOR as it is a VOR/DME Procedure:} :} Smacks a bit of RTFQ no? Never mind, they say you will learn something every day in aviation, and it seems you just have!:E

Hmmmm, have you taken a look at the Gloucester procedures...........

For a start:

http://www.ais.org.uk/aes/pubs/aip/p...s/32BJ0802.PDF

Perhaps you should learn something every day before you open up on others..... :)

BoseX,
I cant get in without a password and i dont want a stream of spam mail, so what is it they have their? I am guessing a DME without the VOR? Or some sort of system using the ILS? Have they got ILS? I have never flown in there in bad weather so not fammiliar with their procedures. All advice will be gratefully recieved, that was the point of the post.

Do you guys realise that you are playing with fire? I mean, if anybody discovered the wind drift rule of thumb, it would undermine all the hours spent teaching the useless circular slide rule in the PPL syllabus :)

Not always. There are Localiser/DME and NDB/DME procedures too.

Gloucester only has a DME and NDB. You can fly a DME arc as part of the procedure. A DME arc is just that a DME only arc!!! The 10degree nibble is the easiest way to fly one. I find that if I mark one eyeball what I think the first heading is, turn on early then watch the the DME as it changes then add or deduct (depending on the direction of the arc) 10 degrees and work my way around the arc.

Oh and for the record that link I sent you is to the AIS site which you should have access to as you are checking NOTAMS and AIP data aren't you?

So I hope you have learnt something in aviation today?
;)

I think it is pretty unlikely that registering with AIS would get you much spam, but anyway...

You can get approach plates for Gloucester from here, without registering:

http://fly.dsc.net/u/Charts?ident=EGBJ

Nope you are wrong. The turn 10 twist actually refers to the heading bug as much as the VOR needles. For example, initial heading 010 fly aloung until the DME changes, turn 10 degress and twist the heading bug to 020 (or 360 depending on direction of arc).

So back to my point, just because you have not done something does not mean it can't be done. A bit like your apology to Whoppity.....

BoseX,
i think i will have to try that on MS2004 as i haven't done that one. But running through the figures it looks like were on the same game. Take a 5 mile dme arc, thats a ten mile diameter circle(well i would hope to fly something like a circle:} ) were trying to fly around a VOR. So That circle will be 31.24 miles in diameter and as a circle has 360 degrees were looking at 36 turnings of the azimuth. Whereas your system would be to fly presumably with the ADF needle off your right wing on a heading of 010 untill the dme changes then trun 10 degrees to the right. Which would mean appx 32 ten degree right turns. I see how that works, i was just never taught it. And i do appologise to Whopity as it seems you can fly a dme arc without a VOR. And who was it saying recently that ADF's were aincient and should be scrapped? Also thanks for the link Drauc, very usefull bit of info that and the plate for Staverton is indeed an NDB co-located DME approach. Maybe thats why i haven't been there in bad weather;)

Originally posted by pumper_bob

OK i accept that there are other DME procedures, but i have only flown an arc on a co-located VOR/DME, and turn ten twist ten will only work with a VOR, otherwise you wont have anything to twist:confused:Unless your listening to Atlantic 252 on the ADF:}




Has anyone been able to get Atlantic 252 in the last five years????

I just googled dme arc and got some good stuff, try this one:-
2006-01-22

Flying the DME Arc

Filed under: system — david @ 22:02:32-0500
Hamish has a posting that mentions how much easier DME arcs are with an RMI display.
Sometimes I feel lucky that I was never taught the official way to a DME arc during my instrument training. We have one nearby, but it just never came up. I flew my first DME arc alone in the plane in actual IMC, and because I was never taught to be stressed about it, it seemed like a simple maneuver. Here’s all I do in the arc itself (assuming that the DME and VOR are already tuned and identified):

1. turn perpendicular to the DME source (so that it is off one of my wingtips)
2. fly my heading until the DME hits about .2 to .3 miles more than the DME arc distance;
3. turn 5 or 10 degrees towards the DME source, and repeat (to allow for winds, turn more if the DME doesn’t start decreasing; less if it decreases too much; don’t let it get less that .2 to .3 miles less than the DME arc distance).

I have one VOR set up as a fence to tell me when to turn inbound, of course. Sometimes I twist the other one to see what radial I’m on, just to relieve boredom, but it’s really not a necessary part of the procedure. I guess that I use the DME as a kind of a digital CDI, and I’ve been happy with the results so far. With my technique, an RMI wouldn’t make much difference, but I can see how it would help if you wanted to track your radial all the way through.



3 Comments »

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Note he said he wasnt taught any method in his ir training! Also, i do see that the ndb dme arc is a reality, however, the google search only mentioned VOR's, so i dont feel such a dummy now:p BoseX, have you ever actually flown one on an ADF?Sorry for the italics, i must have imported them from the post and they wont go away!

Go on tell me! I promise never to use it - honestly:)

So if we are done with the DME ARC, does anyone have any other little gems they are willing to share? And i would also like the wind drift rule please IO540, you cant tempt us and then leave:{

I think he is referring to the clock code trick using your watch.

To start with max drift is half of your total wind taken from the spot wind chart or any other source you can find. Then work out how much the wind is off your desired track. 10 degrees is 10 minutes on your watch which is 1/6 x-wind. 30 degrees is 1/2 x-wind and on until you hit 60-90 degrees where you take full x-wind in which case you apply your max drift to the track to work out your heading after taking into account variation. My CRP-5 is gradually gathering dust as we speak.

Just to refine pot's statement - Max Drift should be wind speed in knots divided by your TAS in nm/min. ie Max Drift = wind/2 if flying at 120kt TAS, wind/3 if flying at 180kt TAS etc etc.

Using it down towards the lower end of the speed spectrum is prone to allowing errors to creep in due to the larger drift angles it creates.

At anywhere near 100kt,

max drift = half the wind (i.e. 20kt wind -> 10 degree offset)

At anywhere near 150kt

max drift = 1/3 of the wind

The above work for a wide range of angles; much wider that most people think. The truth is that nobody (not having an air data computer plus a GPS) really knows what the wind aloft is, accurately enough to make a difference. If you can sort out your heading within 5 degrees, that's just fine. If you have time, you can improve on it as you go along. If you haven't got time (like on an instrument approach) you have other more important things to do anyway.