DR/VFR Nav question

[Tarmach]

Hi all.

How can I apply the max drift number when flying? Also I know about the 'clockface' solutions to work out G/S and drift. However, these seem to be of little use in the air as they use the same predicted W/V as found on the Metform 214 and 215.

Any thoughts about this, how I could use these methods for accurate DR nav when en route, how would I assess the wind accurately in the air? Is it also acceptable to use the wizz wheel in the air?

Any other rules of thumb would be appreciated!

Many thanks,
Tarmach

[GT]

Eyes should be outside of the cockpit - not staring down at whizz wheels (in my opinion).

Regards, GT.

[Final 3 Greens]

Tarmach

My preference is to estimate - if drifting left, then add 5 deg right and see how that works - its an iterative process, but effective in application. Trying to work it our with a whizz wheel can be distracting

Despite the bad press that GPS receives from some, it is also really helpful in this area - you will see bearing to next waypoint and track displayed - a simple subtraction gives you a number on how many degrees off you are - worth having a GPS for this alone, as well as DME substitute.

.... and before all the anti crowd leap in, it's important to monitor the GPS to make sure it hasn't frozen! - also to confirm position by visual reference - I use a VFR flight log/chart prepared in the traditional manner and a GPS and find the more triangulation available, the better!

[Kermit 180]

GT - agreed.

You can see landmarks - fly to them or in relation to them. If you notice that the position marks on your chart are off track, apply a small correction in heading to reach the landmark. Keep it simple, keep a good lookout, avoid collisions with hard objects.

Worry about other methods when you fly IFR.

Kermie :rolleyes:

[Final 3 Greens]

Kermie

You make a good point, but as Tarmach is based in Guildford, I'd just like to add the caveat that lots of landmarks can look quite similar in SE UK .... for example there are many infringements of the Stansted zone every year and the UK CAA report that the lack of features in the locale is a major factor. The congested nature of the airspace in the SE of England makes this a pain for pilots.

So whilst your point is very well made, it is necessary to be very careful in identing the landmarks.

UK AOPA put together a radio nav course syllabus for VFR pilots some years ago to assist in this area.


:)

[ 06 August 2001: Message edited by: Final 3 Greens ]