In-flight Wind Calculations (PPL level)

[matelot]

(Consider a 100-200 mile x/c.) How many PPLers out there perform in-flight wind calculations in order to then set new headings?

Or is it generally a case of the 1:60 rule and its variants to perform hdg and track corrections en-route?

What do other schools teach as a practicality?

Cheers. :)



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Bootneck, Bootneck, can't catch me! Ooh, you are fast, Sergeant!

[Luftwaffle]

As part of preflight planning, draw a track line on your chart and ten degree drift lines each side. When you recognize that your heading has taken you off the track, note the number of degrees, D, off track you are (the 10 degree drift lines help here) and then do one of three things:

1. Visually regain the intended track, then fly your original heading, adjusted in the appropriate direction by D.

2. If you are not yet at the halfway point: note the number of minutes, t, that you have been flying since you were last on track, correct your heading by 2D, fly for t minutes, on that heading -- this will put you on track -- then revert to your original heading corrected by D.

3. Note the angle, C, you are off track with respect to your destination. Correct your heading by C + D. This heading should take you direct to your destination.

How does the 1:60 rule work?

[matelot]

Luftwaffle - many thanks for that. I'm conversant with the methods of regaining track, but it was simply a question to do with re-calculating in-flight wind to set a new hdg, as opposed to using the 1:60 rule and/or the methods you described in order to regain track.

i.e. after 20 miles I'm off track by 8 miles (let's say that's a lot more than the forecast wind). How many would re-calculate the wind in flight (Fix - fix - now got track and g/s, know my hdg /TAS - now calc. w/v), as opposed to other forms of track correction (1:60 or inverse ratio etc)?

Clear as mud, I know! Cheers. :)

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Bootneck, Bootneck, can't catch me! Ooh, you are fast, Sergeant!

[batemanisbad4u]

I suppose most would just switch the GPS on.......now there isn't that a lot easier, maybe now i will have time to fly the plane! AVIATE,NAVIGATE, COMMUNICATE, is what yoy were taught!

Them that won't will a bit!!!!!!

[Luftwaffle]

I don't teach the student to calculate the wind at all, just the new heading. I might ask them on the ground, "seeing as we had to fly 110 instead of 100, and our ground speed was 95kts, what was the actual wind at our altitude?" and expect them to need a bit of help to work it out on the E6B. Trigonometry solutions also accepted.

In flight I wouldn't expect anything more than "the wind is from the right with a headwind component of about 15 kts."

Please tell me how you would calculate the wind in flight, and why. If I've got a box on my dashboard that tells me, great, but do I really need this information? It seems to me that calculating the wind first, then a new heading, is more steps than necessary, but I'm open to new methods.

[This message has been edited by Luftwaffle (edited 02 May 2001).]

[Whirlybird]

matelot,

I've never met anybody who calculates the winds aloft. Firstly, you'd need to use a whizzwheel onehanded, which is possible, but difficult. But more importantly, it seems to me, why would you bother? In VMC, on trips of 100-200 nm, you just don't need to; an approximate calculation is good enough, and gives you more time to do other things - like keep your eyes outside the cockpit. One thing that was never emphasised during PPL training, for me anyway, is the magnitude of errors and what they really mean. For example, if you're 2 degrees out because of a wind change, that's only two miles after 60 miles, and that's accurate enough for all practical purposes. So why make crosscountry flying more complicated than it is already?

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Whirly

To fly is human, to hover, divine.

[Genghis the Engineer]

Calculations are always approximate, whilst landmarks are always fixed. Use the former for guidance and the latter for accuracy.

G

[matelot]

Thanks for the replies, peeps. I'm just doing my nav course. My local school says to ignore in-flight wind re-calcs for the reasons you've come up with. No problem. But TT goes into it in the manual as if it was normal and practical.

So I was just wondering what the feelings of others were as to its practicality. Obviously, anything that keep eyes looking outside has got to be of benefit.

The result is quite clear. Many thanks. :)

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Bootneck, Bootneck, can't catch me! Ooh, you are fast, Sergeant!