Flight computer and navigation
 

Guys

Im still on my groundschool stage, just learning/studying for the nav exam. I have managed to get my head around the whizz wheel, It's as hard as I imagined it to be.

It lead me to wonder how many people actually use it to do their day to flying calculations. Seeing as there are so many electronic devices available these days

So how do you guys plot your route, calculate drift?

I still do, but then again I am still in the training pipeline. Once I've popped out of the other side I am considering buying something like Navbox. However, once it clicks, it is not an onerous tool. I'l stick my neck out and state that if you make a point of using it for calculations and conversions too, you will find it a very handy device on which, in my opinion, it is harder to produce erroneous results than using a calculator.

However the clockface rule of thumb, although nearly but not quite as accurate, actually is just as effective for working out drift and G/S good enough to nav by. I am trying to find a link on Google for it, but it seems to down?? I'll edit later if somebody doesn't add it.

It's quite rare now that I need to fly long legs visually outside of the area I know extremely well - but on those rare occassions, yes I do still use the flight computer.

I think I am probably in the minority, but I'm certainly not the only one who still uses it. Once you know how to use it, it is very easy. I also like the fact that it is visual, making it easier for me to spot errors than many digital tools, it doesn't need batteries - and, most important, I already own it, so there's no need for me to spend money on another tool.

FFF
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You will use it maybe once or twice after you get your licence, then it will get put away and never seen again until it appears on ebay ;) . Whilst it is important to be able to understand the principles of VFR nav (which is what the whizzwheel does) it is simply not a sensible or practical piece of everyday equipment. You will do all your nav using VORs or GPS, and/or you will just use the clock code + max drift (do a search) for everyday use. And you can forget all the TAS/IAS calcs and all that stuff unless you are flying a Blackbird and then someone else will do it for you anyway.
That said don't ignore it just yet, you have a test to pass. And if you want to go commercial you'll have to do it all again on the CRP-5 which is even more expensive :eek:.

I disagree with DB6, I think it is still a useful and dare I say it an enjoyable tool to use. Yes you will probably end up navigating mostly by GPS/VOR but it is still useful to draw lines on a chart and calculate and fill in a plog as well, for the much greater situational awareness compared with just using goto on the GPS.
I may be perverse, but I also get a measure of enjoyment from planning my flights in advance and a great sense of satisfaction when all the headings and timings that I have calculated work out (maybe I should get out more). Lastly when the electrics all go out (it has happened to me) my plog, stopwatch and chart will still allow me to navigate home!
So I say stick with it and keep practising eventually it will all make sense and it them becomes quick and easy to do the planning.

Nigel

I haven't used it much since I passed, but it was something I enjoyed using. I really only use it now to calculte cross winds and occasionally when plotting courses.

In practice I use VORs and GPS as backups but find the stopwatch and wind observation during visual flights the most useful tools. The important thing is to develop a technique you are comfortable with.

Good luck with the exams anyway :ok:

Its not so difficult
 

Think of the whiz-wheel as a triangle of vectors. Draw a vector triangle, then see how is transposes itself to the whiz-wheel and it should help to understand it.
A. the aircraft position,
B. the end of the TAS and heading vector
C. the resultant position of the a/c.
Vector AB is the TAS and heading,
vector BC is the wind,
vector AC is the groundspeed and track.
Point A is an imaginary point at the bottom of the sliding scale.
Point B you mark yourself depending on your airspeed and heading, by sliding the scale, and turning the wheel to indicate the wind from direction.
Point C is the centre of the whiz-wheel.
If you are using the Wind Up method, then invert the meanings of points B and C. (point B is the centre of the wheel, and point C is the start of the wind vector)
After you have marked point B, draw the wind vector, it makes it all clearer.
Yes, I do use the whiz-wheel, as well as the electronic devices. Its a good fallback, and once you understand it, quick and easy to use.
GB.

They are very useful devices when you actually "use" a plane. Just for knocking a hole in the sky for an hour or so, they have very little value. But when you regularly travel from one place to another they are invaluable. No batteries, self contained formulae, useful units and conversions. Well worth the effort of learning how to use it.

I use it for drift/speed/planning calcs, but tend very rarely to use the reverse side for conversion calcs - on the whole I'd rather use a normal calculator for that.

G

An outdated bag of ****e in my opinion. Should be removed from the syllabus.

Agree with superpilot.

Clockface rule of thumb works for me. You can do it in your head and is only a couple of degrees out from the dalton for drift calcs.

Is the wind ever as forcast? Is your HSI/DI accurate to within a couple of degrees? Who said flying was an exact science?

Thanks guys. It seems its all gonna be down to personal taste then. I guess I won't bother spending any money on an electronic device yet. Not until I have passed out and done a few journeys, and see how I feel about it then. So I''ll learn it as well as I can now and worry about making the choice later.

I use NavBox ProPlan but if plans change I'm very happy with the whizzwheel.

I don't find it all difficult to use. As for the back of it, we used logs and slide rules at school so I have no problem understanding it, a minor skill that's all but extinct nowadays.

Mike

Mike What GPS unit do you use with the proplan, Looks really nice. And does not seem that expensive.

Does it plan your altitude to avoid restricted airspace. ie. tells/shows you to fly below/above or even around

The circular slide rule is a relic from WW1. It is taught because we beat the Germans with it (twice actually) so it must be the "proper" way to do flight planning. My grandfather went down the coalmine and my father did too, and YOU will too, my son.... much if aviation is like that, which is great if you don't want too many of the great unwashed coming into it.

Like the signals square, the overhead join, and a load of other cr*p.

It's a complete waste of time. It cannot be used in flight, unless you have a plane with an autopilot, and if you have one of those, as I have, then you will be navigating with more modern methods anyway. Women (who can do two or more things concurrently) might be OK with it :O

The time spent (wasted actually) learning how to use that damned thing would be better spent teaching how to use quick rules of thumb (which are just as accurate, given the typical error in the forecast, but your instructor won't tell you that - even if he knows it), and how to use a GPS. And use a decent flight planning program like Navbox. Come to think of it, Navbox Pro costs only a bit more than the CR&P-1 :O

I've done the FAA IR, and done the FAA PPL before that, and the FAA (which looks after a GA fleet about 10x bigger than the whole of Europe) doesn't require it. Some of the US instructors like it for sure but it isn't a requirement. You can use a PDA running an E6B sort of program if you want.

As for Navbox, no it doesn't provide (useful) vertical navigation, nor is the map quality and information content good enough for CAS or terrain avoidance. In Europe, they would have to increase the price an order of magnitude to pay the mapmakers' license fees (the VFR and IFR charts are free in the USA) so you have to use the printed chart for these things. It's really no big deal. What Navbox gives you is a dead fast plog, wind-corrected if you like, and a simple map to print out.

Have to agree with you IO540.

I don't bother using mine either. Just do quick "back of a fag packet" calculations, and that works just as well.

Sometimes don't even bother doing that !.

:)

Favourite Rules of Thumb
 

Few comments on here about rules of thumb, and I just wondered what people's favourites were. Mine are:
1) Distance from tip of thumb to 1st knuckle is 10nm.
2) Tip of thumb to tip of little finger when hand is outstretched is 70nm.
3) Max drift for around 100kts in a spamcan is wind/5 * 3 = max drift (eg wind 15/5*3 = 9 degrees max drift)
4) Use of the clockface to work out how much wind to allow for.
...any others.....?

Having said that I've just bought myself a Garmin 96C and was wondering whether Navbox or something similar would be a smart purchase as well. Any advice?

C23

Max drift = half the wind (100kt) or 1/3 of the wind (150kt). Anything more precise is wasted in the error in the winds aloft forecast.

Navbox Pro is the way to go for European VFR and "UK-style" (i.e. Class G mostly) IFR. You get 28-day updates and these come from the national AIPs, same as the vastly more expensive Jeppesen data (which I have used also). I am not aware of any other flight planning program for Europe which gets proper regular updates, and updates are crucial.

I dunno where mine is anymore, seeing as I haven't used it for 5 years :O I preplan properly on the computer which works out my CoG, SoG, Compass headings and all that stuff, then if I need to change it in the air I use rules of thumb, and GPS to give CoG, SoG, and actual winds......

I tried planning properly for my IR checkride several years ago, filed my flight plan which included a SID, then picked up my clearance and it took me a completely different route anyway......so now I just make sure I'm not going to run out of petrol and off I go. If I need to divert, there is always the Goto button :)

IO, are you now a member of the Elite then (if so, congratulations!) ? Are you back, I'm off over there on Wednesday......
Cheers

You can also try the too-lazy-for-a-whiz-wheel-when-you-can't-afford-navbox-or-don't-have-it-to-hand-or-are-using-a-Mac-or-a-PDA-or-need-to-plan-to-some-obscure-little-town-and-you-want-a-google-overhead-photo-of-it online tool: http://fly.dsc.net