Navigation exam - do I have to use the Whizz Wheel?

[Odai]

Hello,

I am currently studying for my PPL navigation and flight planning exams. Got all the others out of the way.

The only problem I have with the studying at the moment is the use of the Whizz Wheel. To say I absolutely despise the thing is a massive understatement. :D

I appreciate it's importance in calculating various essential bits of information, but I prefer to use my own methods to do so.

For example, when calculating headings, drifts, ground speed etc, I always work it out myself with algebra/trigonometry/vectors.

When I was first introduced to navigation by my flight instructor two years ago (it's been a while since I've flown, taking a break for medical reasons), he did try to get me used to the Whizz Wheel. But I had great difficulty doing so. So, he let me do all the planning myself using my own methods, then he'd check up on my numbers using the Whizz Wheel. I was always spot on, same numbers.

Although it's insignificant, my numbers were exact right up to rounding at the very end of the calculations. Whereas with a Whizz Wheel, you'd be using rounded, whole numbers right the way through. So a bigger potential for inaccuracy there. :p Not to mention Whizz Wheels that have been poorly manufactured, using a pencil that's too thick, hand slipping etc...

I did that for the rest of the time I was flying. Never touched the wheel and I was perfectly happy. However, at the time my instructor did stress that it wouldn't be enough for the exam, and that the CAA would want me to show that I could use the wheel. (Although, I don't recall if he was referring to the actual navigaton theory exam or the skills test.)

However, I did read somewhere that you are allowed an electronic calculator for the exam. In this case, I could get by without a Wheel, I just need the calculator for hard arithmetic and working out tangent/sine/cosine values etc. But is there an actual need for me to show I can use the Wheel, as my instructor said? Or will I be OK if I can just get through the problems in the exam using other methods?

I'd really appreciate any advice on this.

Thanks,

Odai.

[WILCO.XMG]

You will need to learn how to use the flight computer.

Especially for unit conversion.

Spend a few days going over the instruction booklet you can get with the whizz wheel.

Then go spend an hour ground school with your instructor. You will have no problem picking it up.

[homeguard]

No, you are not required to use a 'whizz wheel'. You may use a simple calculator (not a programmed or programmable) type.

Therefore, you will need to know the conversions for measurements of US, Imperial and metric volume/mass etc, and the other calculations, simply done on the maths side of the whizz wheel, such as TAS and true altitude.

[IO540]

Section 2.7.9 - non-programmable calculators are allowed.

All I can say is .... when did this come in?

:ok::ok::ok:

This is astonishing. I did my PPL in 2000/2001 but ever since it has been standard ideology handed out to all PPL candidates that the circular slide rule is mandatory :ugh:

So many hours are wasted on learning that stupid device. There is no mandatory ground school in the PPL, so ad hoc evening classes (etc) are organised to cover this one thing.

The calculation side of the slide rule is a total waste of time because a calculator is much easier to use.

The wind side of the slide rule is hardly better because the accuracy is illusory, given the lack of accuracy of the winds aloft forecast, etc. A simple rule of thumb is just as good.

The interesting thing, however, is that the CAA multiple choice exam questions were rigged to have some answers 1 or 2 degrees apart, to catch common slide rule errors. If one now uses a trig function calculator and works it out potentially precisely, will the "right" answer be generated?

[captainsmiffy]

The whizz wheel is a great bit of kit and, in my 3000 or so hours of instruction (given, not received!) I usually found that studes with a problem on the wheel had these problems built in from poor instruction received, often by people who didn't understand the thing themselves!

Maybe I am starting to get 'long in the tooth' these days and I am biased by being an ex nav student but the whizzwheel does (should) get you thinking much more about the wind and its effect on drift with varying airspeed and should really be a 'must' on the syllabus. Full marks to anybody doing it trigonometrically but not so practical in the air, methinks!

Anybody interested in my old tome on 'Diversion Planning', which shows you how to do the whizzwheel stuff in your head?

A shame that my A380 doesn't have a stowage for a whizzwheel....am getting rather perplexed with all of these computers!

[24Carrot]

If one now uses a trig function calculator and works it out potentially precisely, will the "right" answer be generated?

In my limited experience, yes.

All I can say is .... when did this come in?

I don't know, but it has been a few years at least. When I did my PPL exams I used a 4-function calculator though I had to show some CAA document to the examiner's delegated FI a couple of times.

Sadly, I was too conservative about what a "programmed calculator" was back then, and I took it to include calculators with sines, cosines, etc. At later IR exams at Gatwick, calculators with trig functions were fine.

[IO540]

Full marks to anybody doing it trigonometrically but not so practical in the air, methinks!

You are hardly going to use the circular slide rule in flight. What for?

[Genghis the Engineer]

IO540 and I have crossed swords about the whizz-wheel many times on Pprune, and I freely admit to being a fan of it, whilst he clearly isn't.

However, in this case I'm going to come out being a little on the anti side. There is no rule requiring you to use the device, and there are other manual ways to calculate drift and groundspeed.

Using something like an fx83 and doing trig calculations is only using an electronic calculator instead of the analogue calculator which is the whizz-wheel and perfectly legitimate most of the time.

Very rarely is there any good reason to use the device in flight, as IO540 rightly says. You have other things to worry about and plenty of methods to mentally correct for corrections and diversions.

In one of my CPL exams I recall a nasty calculation that gave me results on the question paper within a tiny margin of each other and I just wasn't getting a consistent answer from my Aviat 617 (ultra posh version of the CRP-1); I eventually used my ruler and protractor to mark out the vectors on a chart and measured the answer. This is also, as it happens, how the old PPL(M) nav used to be taught, although I'm unsure if that's still the case with the NPPL?

That said, if, say, you plan to go commercial or instructor you will almost certainly need to master it and it is a useful tool so I'd recommend persevering in learning how to use it. But it's not vital at PPL level.

G

[CharlieDeltaUK]

My first whiz wheel was rubbish - it was poorly consructed and subject to inherent errors even beyond the norms. After a post on here, I bought a better one. And this time I bought one with a 'wind arm' which makes it much easier and more intuitive to use.

The OP obviously understands vectors, and the whiz wheel with the wind arm was a very good visual representation of the vectors. Best of all, it didn't require any of that silly jiggling that seems to me necessary otherwise.

Before that purchase, I too was thinking I'd simply use the trig functions on my calculator because I was fed up with getting the wrong answers in the practice nav questions due to the poor construction of the old whiz wheel. The new wheel sorted that and I have to say there's a certain amount of satisfaction with the simple elegance of using a non-electronic device to calculate these things. Use it often enough and it's quicker than a calculator (and I say that as a mere student, so hardly experienced) - no need to write down intermediate answers, for example. Nav is what I enjoy most about flying.

My biggest complaint was that I found it was a strain on the eyes. I'm not long-sighted by 'normal' standards, but I found that using the whiz wheel (and indeed the charts) was more relaxing for the practice questions and exams if I used a cheap pair of reading glasses - they act as magnifiers. Not rquired in the air because that level of accuracy isn't needed.

[DX Wombat]

All I can say is .... when did this come in?
It was certainly in place when I started my PPL in 2004.

[Maoraigh1]

I used a non-programable scientific calculator in 1987 when I re-sat my exams after a 20+ years lapse. As I was current on trig, it was easier than re-learning the wheel I'd bought in 1964. (And more accurate and quicker)

[Pace]

Good Old CAA and I stress the word Old! I am surprised that they still dont insist on using a bi plane with canvass wings for your PPL.

Fact is who practically uses one of these nowadays?

I have not used a whizz wheel for decades and have never seen anyone using one post PPL?

Pace

[riccioenzo]

Did the nav exam 3 months ago. Using the wheel you don't get the most accurate results, but the multiple choice answers are 'far' enough apart to rule out the wrong ones. Good luck

[Piltdown Man]

Maybe this isn't relevant, but a few years ago, one of the best ever CPL/ATPL teachers around - a guy known as "Rapid Ron" (Ron Bayne?) swore blind you didn't even need a calculator to do the CPL Nav. exam. Now I had been indoctrinated to believe that such a thing was a 'must' so I used mine to come up with the first 'answer'. However, I was able to confirm each and every answer (by doing the paper again) without use of calculator or whizz-wheel. Fancy maths is just that, but what you really needed is 'good enough' maths. When checking my answers, it was very clear that you had to give answers starting with an 8 and not a five, or in Miles and not Kilometres and so forth. I'd expect that current PPL papers would be similar.

PM

[Whopity]

I always work it out myself with algebra/trigonometry/vectors.
The Wizz Wheel is only a mechanical Vector Triangle plotter; if you understand the principle, then you couldn't find a simpler solution.

[S-Works]

I never touched the whizz wheel in the CPL or IR exams. I don't even recall using it in the PPL either.

[captainsmiffy]

Quote:-The Wizz Wheel is only a mechanical Vector Triangle plotter; if you understand the principle, then you couldn't find a simpler solution.

Yes, it is, on one side. Depends to which level in aviation that you aspire as to whether it is only a mechanical vector triangle plotter or not. Lots of uses on the other side relevant to the ATPL exams that I did, granted a few years back. As for the mechanical plotting for light aircraft use - I can do all that in my head virtually as accurately as the whizzwheel. Have written it all down in 'Diversion Planning' if anybody is interested.

In reality, now though, for me - the whizzwheel is a thing of the past on the big airbus....

[BillieBob]

the whizzwheel is a thing of the past on the big airbusThe problem is that it remains very much a thing of the present in the PPL theoretical knowledge syllabus, both under JAR-FCL and under Part-FCL. The requirement under JAR-FCL is clearer, referring specifically to "use of the circular slide rule", whereas the Part-FCL syllabus refers only to "Use of the navigational computer". Although the term 'the navigational computer' is not defined, the intent is clear and it is difficult to imagine that the CRP-5 and its bretheren are going to be out of our lives in the forseeable future. It will also be interesting to see what appears in the learning objectives for the EU CPL and ATPL when they are published
So the UK CAA are still not quite in the 21st century just yet.
:D Classic!! It took me a long time to stop laughing after reading that.

[Whopity]

I can do all that in my head virtually as accurately as the whizzwheel.I would hope that anyone with any relevant experience can, and its what we are trying to teach PPL students to do, but many find it difficult if not impossible therefore, they need a simple fall-back method that is well tried and doesn't rely on batteries, A-level Math, or the Internet.

[UL730]

Although I no longer use my old CRP- 4 – when it was “mandatory” for the exams I did at Gatwick, I found smearing the rotational parts of the device with a very fine film of lanolin made it a lot easier to use especially when a lot of calculations were required quickly – to stay within time limitations of the exam.

This small modification helped greatly and allowed one to focus on high value questions (with negative marking) associated with a UK departure time given in BST to arrive at an airport in Holland with published hours referenced to GMT - before it closed - based on the navigational route you had just carefully plogged and extracting data from some horrible almanac.

(with all the post exam “well could you or couldn’t you” questions afterwards in the congregation of the Belgrano atrium - with about a 50/50 split and the horrible thought of loosing 14 points just on that one question if miscalculated)

[BEagle]

CAA not yet in the 21st Century?

Judging by their attitude towards GPS, it's clear that the abacus is a bit too high-tech for some of them. The few remaining ex-aircrew at the Belgrano are firmly established in the lodestone, astrolabe and quadrant staff age of navigation.

[Intercepted]

Quote:
I can do all that in my head virtually as accurately as the whizzwheel.
I would hope that anyone with any relevant experience can, and its what we are trying to teach PPL students to do, but many find it difficult if not impossible therefore, they need a simple fall-back method that is well tried and doesn't rely on batteries, A-level Math, or the Internet. I for one has stopped calculate wind corrected headings pre-flight. If I understand correctly, this is something many FTOs would not accept.

[IO540]

Unfortunately, because almost nobody doing the PPL today has ever been exposed to a slide rule in its traditional context (which ended mid-1970s as soon as calculators came out, particular scientific-function ones) most think that one side is a wind triangle calculator (which is true) and the other side is some magical converter device (which is wrong; it is just a straight slide rule (a multiply/divide device) bent into a circle, and with some common conversion ratios marked on it.

A standard slide rule is a geometrical implementation of the mathematical principle that to multiple 2 numbers you take their logs, add the logs, and antilog the result. For division, you subtract the logs.

So, by lining up the two logarithmic scales next to each other so as to add the two distances correcponding to the numbers to be multiplied, you get the result directly.

This was discovered several centuries ago, and has provided a great way of calculating things. A decent long slide rule can give you 3 significant digits straight off (with care) and that is fine for nearly all mechanical/civil engineering calculations.

One can argue about the use for the wind triangle for dead reckoning work for student pilots, but I cannot see any point in the other side. It is just a multiply/divide calculator. Electronic calculators whose batteries last practically for ever have been out since about 1977, and the slide rule has been dead since then, for multiplication and division.

And using the slide rule for mult/div is much more error prone than using a calculator. It is easy to mis-use the pre-printed conversion ratio markings, for example.

In practical aviation usage, you don't need to remember that many conversion factors. I use only 3.78 - USG to litres - because my plane was built for a US customer so it all in USG, but avgas deliveries are presented in litres so, even though I always fill right up, I have to do the conversion after each fillup to check that the onboard fuel totaliser is within its normal error of about 1%.