Foxmouth,
A technique used by some instructors in Australia is to mark the map in 'time markers'. Obviously when tracking into wind, the markers will be closer together than when tracking with the wind. And it must also be apparent that such markers are only accurate when the winds are as forecast. A change of wind or cruise technique renders the marks useless.

By marking in ten or twenty mile intervals, each mark will still be valid regardless of the direction travelled. The time to transit the marks will vary and any student with grade school math should be able to interpret ETA's accordingly!

BH - do you HAVE to be insulting in the way you change peoples screen name or is this just your juvenile sense of humour - I could do something similar but have so far restrained myself!
From my experience the Aus met does not get its forecasts as wrong as you seem to indicate and so timings for points closer than 50 miles or so should not be out by more than a couple of mins or so unless you are using the wrong days forecast, even then correct application of ETA updates should allow you to make half decent forecasts for time to turning point.
Also, by using the 'distance' markers is STILL as I pointed out in my last post, using time markers anyway, just instead of knowing the time between points and then working out the distance to mark on the map you are marking a distance then working out the time between points, hopefully you STILL teach that you know when to start looking for the marker point by looking at the watch to know when that point is comming up, or do you just leave it to luck?
An additional point is that, as you have said, using time means that the markers can becloser together on some legs than others due to wind, but you are then doing checks at regular time intervals, what you seem to be suggesting could in theory mean you have a nav check every 6 mins on one leg (fine), but every 20 mins on another leg (not so great), admittedly this would be a very strong wind, but you have talked about WORK, and sometimes then you do fly with very strong head/tailwinds!

[ 26 October 2001: Message edited by: foxmoth ]

[ 26 October 2001: Message edited by: foxmoth ]

[ 27 October 2001: Message edited by: foxmoth ]

Foxmoth,
My sincere apologies – I misread your ‘handle’ and in no way was attempting to display a ‘juvenile sense of humor’.

My response to the original post by FFB was based on experience in remote areas a long time ago. In that post I pointed out that variations in windspeed and direction encountered on long legs rendered the use of time markers useless. Satellite imagery (in the sixties and seventies) was in its infancy, and in a country this size ‘met’ observers are few and far between. And yes, the forecast winds were not always accurate. Nor are they today.

No, I don’t use six minute intervals. In fact locating suitable features in central Australia at fifty mile intervals can be a challenge unless you dog-leg all over the country side. Ten mile markers serve to quickly calculate the distance between such features and determine G/S. They also enable a quick check of ones probable position by estimating the distance flown over time since the last checkpoint. They are excellent for calculating 1:60 solutions (a distance not time calculation). Most of all they are still on the chart next day or next week when you are tasked to fly the same route, perhaps in a faster or slower aircraft!

Finally you seem to have some aversion to the term ‘distance marker’. To quote a 1983 publication by T. THOM on navigation: “To allow in-flight estimation of flight progress…put in 10 NM markers. Some people prefer to use time markings…but these change from day to day depending on the wind, the aeroplane and so on.” They are measures of distance and not time!

In teaching students I draw on tried and tested practical experience, not necessarily the teachings from a text book. After all the luxury of a classroom does not replicate the confined space of a cockpit bouncing in turbulence and pressed by the urgency of bad weather and/or fuel limitations! Ten mile markers keep it simple.