PPL Navigation

[ACARS]

All

Just starting on flight planning for my PPL. If you are flying from A to C, via B and the wind forecast is different at all locations, at what point during the flight plan to you compensate for the change? e.g leaving A its 300/20kts and arriving at B its 010/10kts.

[Code Blue]

ACARS:

For practical purposes in PPL nav, I would suggest you simply average the winds between the waypoints for a single wind value for each leg, remembering that you need to use the winds at your cruise altitude for the calculations. That will also give you an accurate enough answer for the written exam. :D

I have tried to calculate corrections for each site and apply them to parts of the flight. It is unnecessarily complicated and makes a difference of only a few degrees (usually less than 6 deg). The main thing I find is to have checkpoints reasonably spaced so you can see them from each other - in the UK that should be fairly straightforward. You'll end up flying a wind correction angle by eye.

For legs of over 300 NM I have used pressure pattern nav and ignored the winds but that generates its own problems!

Rgds
CB

[pigboat]

Code Blue, would you e-mail me please? Got some QX pix you may be intereted in, and your pprune e-mail address doesn't work.

[BEagle]

Just use the mid-point wind for each leg.

[Blackshirt]

In the written PPL Nav exam, they give you a flight planning log sheet with the wind velocity and dir for each leg already written in for you.

It's not a difficult exam to pass as long as you are proficient with the Crappy-5 and are familar with airspace info on the charts.

When you're actually flying, you'll be VFR anyway so just look out for landmarks along your route.

[ 07 October 2001: Message edited by: Blackshirt ]

[Di - Hedral]

For practical purposes Code Blue has given you the most accurate and informative answer.
Use an average wind for each leg for the altitude that you intend to fly at. Interpolate from the windchart.
If you decide to embark on very long nav exercises once you have obtained your PPL then you can always break the long sectors into 2 or 3 parts, particularly if the wind varies dramatically eg through frontal systems. Worry about that when the time comes.
Some days the charts are more accurate than others, which is why you are going to learn all about track error & correction angles and the 1 in 60 rule.
GOOD LUCK, but most of all enjoy the learning experience! :cool:

[twistedenginestarter]

A slightly touching faith in the Met Office.

Given that all the winds they give you are wrong, you are ill advised to fly by dead reckoning. Your forecast wind just gives you an assessment of fuel required and potential problems en route eg too much cross wind on landing.

You actually fly by pilotage. You compare your map with your track required and timings. You are judged by arriving within 2 mins of your ETA but not the ETA you got from your plan but rather the one you get from your pilotage assessments.

[Code Blue]

twistedenginestarter has a fair point about the forecast winds in general, though I have no experience of your Met Office.

As you find yourself with some free time aloft on a long x/c :D , you could try a "Missing Wind" problem and verify the forecast winds for yourself. I have done that on a few occasions and found the winds to be within 15º and about 7kts of those from FSS.

Often though the winds have changed significantly, especially if you do up your flight plan the night before with 12h forecasts or longer ahead. Then pilotage is how you actually navigate - unless you use radio navigation.

rgds
CB

[Hermie]

Hi,

I was just wondering, whether if its possible for the ATCO to vector us and inform us that we are off track or something like that....

Just wondering, would it be too much of a hassle for the blokes ?

Thanks

Cheers,
Herman :cool:

[twistedenginestarter]

Hermie

I don't think it's polite to ask them to do that. You are however free to ask for bearings. It used to be part of the Cross Country Test when I was a boy, if I remember rightly all that time back.

If you're lost you can ask anyone anything, switch to 121.5 if necessary.

Trouble is the whole thing is geared to spending half your life proving you can navigate with nothing else but a compass and a kleenex tissue. Next minute you've got triple INS and you never need to use your finely honed skills ever again... :rolleyes: