ALEXA

Looking at other threads (e.g. the recent one about PPL skills tests) I notice that most people's diversion planning seems to be done by mental dead reckoning or by using a whiz wheel in the cockpit (beats me how).

Why doesn't anyone ever mention the Knightson computer, which is an absolute doddle to use, as long as you remember to mark the wind on it before setting off? Is it just that Mr. Knightson is very bad at publicising his wonderful invention?

Cabotage Kid

Not familiar with said 'puter.

You could always draw a compass rose on the map with 8 cardinal points. For each point write the drift, ground speed and, if you like, the time to do 10nm. You get your diversion, just lookup the nearest cardinal track to get your heading and ETA. Can it get any easier?

ThePirateKing

Hi,

I mentioned them a few posts down this page: http://www.pprune.org/forums/showthr...n&pagenumber=2

Nobody really seemed to know what I was talking about!

Do you know where I can source a new one? The one I had was supplied by the flying school.

TPK

ALEXA

I got mine from the flying school, but the phone number which comes with the instruction shhet is 01234 741647. [Moderator: please remove if this offends the rules.]

As for how it works, well, it's a transparent disc marked with concentric circles for the wind and with the 360 degrees of the compass round the edge.

You just mark the wind on it before you fly, using an indellible marker.

When you divert, you mark your line on the chart in the usual way, place your wind dot on the Knightson over the start of the line, aligning the Knightson to true north. You then simply read the heading from the edge of the Knightson by looking at where you line meets the edge, add magnetic variation and there you are.

As for timing, the distance from the point of departure to the edge of the Knightston is 6 minutes. Simply realign the Knightson from the six minute mark for longer diversions, all in multiples of 6 mins.

No mental arithmetic (apart from mag variation and multiplying by 6 to get the time to the alternate).

The only downside is that you must have a different Knightson for different airspeeds. If you fly lots of different types, you might accumulate a collection.

Crosswind Limits

Mr Knight is a clever man - I still use mine!

The Trolls' Troll

What about a set of instruments that gives you an up-to-date wind vector and allows any diversion to be put into effect at any time? Easy to use in the cockpit because of the good size, employment of colour, easy to manipulate and very tough and reliable. Designed for en-route but does the pre-flight as well. That’s the Navok system--Navok.co.uk or click on the www at the top of this post.