The Civil Aviation Authority and the Electronic Flight Computer

[Minos91]

Very good evening to you

I am in a bit of a dilemma as whether or not to go ahead and purchase an electronic flight computer.

I am currently doing my PPL.

My concern is that can I use an electronic flight computer for my exams? and even for ATPL's in the future?

Many Thanks

Minos

[BEagle]

Although electronic calculators are permitted for PPL exams, those with any navigation programs or software are not. Neither are mobile phones allowed into the exam room.

[IO540]

They are also IMHO of little use in real flying, where the planning is done quickly and efficiently on a laptop which has the aero database etc on it. Also in practice you need a laptop for getting weather etc. when away from base.

[patowalker]

Oh, it's not all that bad. Our pilots sit in the left seat. :)

[Spcialeffects]

I am doing my PPL as well, got 10 hours, and have just done my nav exam. Had to learn how to use the 'Flight computer' and i must say what a great piece of kit why would you want to go digi? Anyway as the book says it never gets flat batterys!! stick with it and learn it properly its the only tool you'll need

[IO540]

You will make a fine instructor one day :)

Just do what most instructors do and never try to fly past the nearest crease in your map :)

In fact, with the rate at which people are leaving the CAA, they might offer you a job on your pprune posts alone :)

[Justiciar]

The "Flight Computer" is essentially a round slide rule. I remember my large slide rule being my pride and joy at school. I quickly dumped it when Clive Sinclair's calculators came within financial reach. The rest is history.

Quite why the CAA are wedded to this device is quite beyond me. Like any mechanical device it is prone to user and reading errors and because of its logarithmic scale it is more difficult to read between 9 and 10(0) than 1 and 2! The wind scale on the reverse is similarly prone to error. To argue that it is an important skill to be able to use one is like saying that doctors should still know how to bleed people or motorists how to manually advance and retard their ignition. The argument that it has no batteries to wear out is a complete nonsense as an electronic flight computer is inherently far more reliable and less error prone and will only be used on the ground where if the thing dies you will have access to many alternatives anyway. Furthermore, no one uses it in flight as it requires more hands than any of us have and put your head inside the cabin for too long when it should be looking out.

I have given up putting in a wind calculation into the plog as winds are never what they are forecast to be (I did on a recent trip via Skydemon and the resulting heading was way out!). The skill is in assessing the effect of wind on your track and compensating as necessary; the amount of compensation will vary during differing parts of all but the shortest of trips and of course it will also change both in direction and speed if you are forced up or down from your planned altitude.

The reality is that as the vast majority of people now use a PC for Wx and Notams a substantial majority in all probablility use it for their flight planning as well. When you have things like Skydemon light for free why would you rely on a difficult to read protractor for tediously making up your plog? That is not to say that you don't use a chart. Not only must you have a chart but it is essential to plot a line on it and to know independently of GPS where you are. I now plot the line from the date produced by the electronic plog and mark the headings on the map from the plog along with six minute timing markers.

Learning with a flight computer is not "learning properly", it is making life difficult for yourself by using an inaccurate, inherently error prone device which the rest of the world gave up on 40 years ago. The worst thing you can do is copy the data from a flight computer into your plog and then slavishly follow it irrespective of actual conditions.

[IO540]

The circular slide rule wastes about 5-10 hours of the already scarce (and non mandatory) PPL ground school which would be better spent teaching pilots some operational tips on how to fly from A to B, how to use the internet to get weather, notams, etc.

More practically, the accuracy improvement through using the circular slide rule for wind drift etc, over a rule of thumb like "max drift is half the wind" is less than the typical error in the winds aloft forecast.

The calculation side of the circular slide rule is totally pointless, and is very error-prone.

[proudprivate]

Had to learn how to use the 'Flight computer' and i must say what a great piece of kit why would you want to go digi?


Because digi is alot faster and more accurate for flight planning. And because a few rule of thumbs are a lot safer than diddling around with a circular slide rule in flight when you should be watching traffic.

I found the E6-B amazing when I first learned to work with it. But then I realised that software does the trick much more efficiently. The AOPA flight planner, integrating forecast winds aloft into a log, is simply amazing. A pity that we don't have this is Europe (at least not for a € 40 membership fee).

To students, I would recommend writing some software that does what the E6-B does, to make sure that you've grasped at least the methodology behind it and to learn some orders of magnitude of typical wind corrections. I did that after completely messing up my first holds (during a hefty crosswind) for my IR.

But it is ridiculous to insist on the use of a 1940's instrument when alternatives are commonly available and which in practice nobody uses anymore. (This is contrast to the VOR, which is also a 1940's instrument but which people in practice still use :) )


I have given up putting in a wind calculation into the plog as winds are never what they are forecast to be (I did on a recent trip via Skydemon and the resulting heading was way out!).


That is a recommendation that I cannot subscribe to. For long cross-country flights, a turning or increasing wind can mean the difference between making it with reserve and not making it at all. You want to anticipate this by simulating a variety of realistic wind strenghts and directions to see what gives.

I fully subscribe to the other points you are raising.

[Justiciar]

Maximum drift is windspeed divided by airspeed in nautical miles per minute, or Max Drift = Windspeed x 60/Airspeed (knots).

Once you know the maximum drift then a rough rule of thumb calculation of actual drift is to apply a factor depending on the wind angle and using your watch face as a guide, e.g. if wind is 30 degrees off heading then the factor is 0.5 (half way around the watch face), if it is 15 degrees the factor is 0.25; anything over 60 degrees and the actual drift is the maximum drift! Quite easy to work out (you mark maximum drift somewhere on your chart before you go) and work it out actual drift in your head if you need to.

You will be unlikely in practice to fly to any greater degree of accuracy that a computer might give.

That is a recommendation that I cannot subscribe to. For long cross-country flights, a turning or increasing wind can mean the difference between making it with reserve and not making it at all. You want to anticipate this by simulating a variety of realistic wind strenghts and directions to see what gives.

Depends how long is "long" I suppose, but the longer the flight the less likely that the wind given pre departure is likely to be accurate, so you are going to have to recalculate on route anyway depending on actual wind. I agree that you would need to anticipate worse case by pre-calculating a maximum likely wind and its effect on range, but that is a different exercise from religiously making up your plog with data which has probably never been correct and then flying to it. I suspect anyone flying a distance far enough for that to be an issue is either going to have an aircraft with a huge range and a gps which will give fuel required to destination or they will be in something like a Cub which can land at a local filling station when the wind reduces the ground speed to 40 mph!!

[IO540]

The extent to which one should do a wind-based plan depends on how much reserve you have and what cockpit instrumentation you have.

I have an aircraft with a 1300nm range (to dry tanks) and this makes the vast majority of flights within Europe doable with a big reserve. I also have a fuel totaliser (accurate to 1-2%) which is linked to a GPS and this displays a constantly re-computed "landing fuel on board" figure, based on the current GS, etc.

Put that together with a quick look at the MSLP chart to what kinds of winds aloft might be expected, and there is rarely a need to do a traditional PPL-style wind corrected plog.

Otherwise, if using a laptop flight planning program, there is no harm in putting in some sort of average wind figure...

Obviously, all this assumes that you have constant lateral track guidance i.e. GPS or VOR/DME. If one is dead-reckoning, one needs to fly wind corrected headings to have any chance of getting it right.

You will be unlikely in practice to fly to any greater degree of accuracy that a computer might give.

which is true even if you have a slaved HSI system and are flying a heading on an autopilot. If flying manually, with a typical knackered spamcan DI, a rule of thumb will be better than any accuracy a pilot can achieve.

[mad_jock]

To the orignial poster.

If you are going onto ATPL's get a CRP5 you can get them on ebay or buy direct from pooleys.

The electronic thingy is nice but won't help you in your training.

After the ppl stage you will use it in theory exams and thats about it. Once commercial you proberly won't use it again unless your car window is iced up and you need something to scrape it with and the previous CD case which was acting as your scraper has given up the ghost.

[dublinpilot]

I can't believe you all are discussing the merits/demerits of the flight computer again :E

As for I am doing my PPL as well, got 10 hours, and have just done my nav exam. Had to learn how to use the 'Flight computer' and i must say what a great piece of kit why would you want to go digi? Anyway as the book says it never gets flat batterys!! stick with it and learn it properly its the only tool you'll need

Well the person registered to make that comment. I'd be pretty certain that it's one of the regulars here who just registered to see if they could bait someone ;)

[IO540]

Yes, very possibly :)

BTW, the circular slide rule is no longer mandatory in the IR or ATPL exams. I don't know if it is mandatory in the CPL exams.

[mad_jock]

What do you use instead of it IO?

I seem to remember my Gen Nav was 3 hours of furiously spinning the bloody thing wishing I had taken it to pieces and sprayed it with lub before I went in.

[IO540]

For normal calculations, one uses a calculator.

For wind drift calcs, you can also use a calculator (with sin/cos functions), but there are few if any of such questions in the exams now.

As I said, there may be some such questions in the CPL, which is a purely VFR dead reckoning exercise, and I don't know if they allow calculators in there.

I've now done all the IR exams (ATPL subset) which might have contained wind drift calcs, and did not see any such questions. The FTO study material (GTS) was full of them, however, but that is another story..........

[rasti121]

BTW, the circular slide rule is no longer mandatory in the IR or ATPL exams. I don't know if it is mandatory in the CPL exams.
It wasn't needed on mine JAA CPL (or IR). There was a question that needed IAS(CAS)->TAS conversion but "the rule of thumb" TAS=FL/2+CAS was accurate enough (to be closest to the right answer, as you do on these tests).

[IO540]

Actually TAS calcs are a fair point, because the conversion has to include temperature.

You can still use a calculator if you can remember the formula, but I brought the Jepp CR-5 (http://jeppesen.com/download/misc/crinstructions.pdf) in for this (but never used it).

[XX621]

If we are referring to the CRP-5 (or equiv) a.k.a. "Whizwheel" I can assure you it features very prominently in the JAA (UK CAA) Gen Nav ATPL examination. You *cannot* pass that exam without knowing how to use it for a wide range of calculations - been there, done it (recently).

The continued use of the CRP-5 in the PPL/CPL/ATPL exams in this day and age, is (IMHO) simply to test understanding of some very important basic principles of pilotage; diligence and ability to learn and apply. To argue it should be removed from the syllabus because it has been superseded as a practical tool is kind of missing the point....

[Tinstaafl]

IO540, you could have used a Jepp CR from the start if you wished. I've been using a Jepp CR5 (the smallest & therefore least accurate of the CR series - but still at least as accurate as the UK CRP series) since 1987 when I did my Oz IR. Used it for my Oz ATPLs, FAA ATP & UK ATPLs. Some problems** require fewer steps than the CRP so that's a beneficial point to them. I also find the wind side easier no matter what type of wind problem it is. About the only time I've used a slide type since the '80's was when a student wanted to learn use one.

**Those were ATPL Mach No. problems. Don't know if the JAA IR exam goes that far.

[IO540]

I agree; the CR-5 does the wind calcs too so basically does everything needed.

I didn't realise a CRP-5 was mandatory for the ATPL exams. Yeah, I bet all the BA pilots carry one ;)

[mad_jock]

that was my understanding as well.

And the answers by the CR-5 are slightly different to those by the CRP-5 and you guessed it both will be in the list of available choices.

BA pilots don't need to carry one to my knowledge but it is SOP in some airlines to carry one. I used to carry a small whizz wheel without the wind stuff for doing enroute fuel and fuel uplifts, I very rarely used it. I lost it and as the machine does the enroute fuel and a cheat sheet in the techlog does the fuel converstions I never replaced it.

[IO540]

BA pilots don't need to carry one to my knowledge but it is SOP in some airlines to carry one

How delightfully reassuring, darling. Not half as reassuring however as the dashing pilot with the great hair and oh such a well groomed upper class voice.

Carrying a CRP-5 on a jet is like watching one of those 1950s documentaries on aviation, when the hostesses wore proper short skirts and high heels.

What century is this?

[Justiciar]

The continued use of the CRP-5 in the PPL/CPL/ATPL exams in this day and age, is (IMHO) simply to test understanding of some very important basic principles of pilotage; diligence and ability to learn and apply. To argue it should be removed from the syllabus because it has been superseded as a practical tool is kind of missing the point....

Perhaps trainee pilots - who clearly are so immature that they need to further domonstrate those qualities - should do their exams using a quill pen and ink pot. Writing with such an instrument is clearly a skill which should not be lost:ugh:

On a serious side, the knowledge and skills applied using an electronic calculator are exactly the same as those applied using a manual flight computer. In fact, using modern technology is far more relevant when you take into account the reduced risk of error inherent in an electronic device and on line systems for flight planning as compared to protractor, ruler and wizzy wheel.

[mad_jock]

To be honest somefolk get on better with a whizz wheel than a calculator.

Being an engineer in a previous life a scientfic calculator was my prefered method and fastest as well. Some of the people on the brush up course it was the other way round they prefered the whizz wheel and got quicker/correct answers using it.

Some folk hate others its a god send. Can't win really.

[IO540]

To be honest somefolk get on better with a whizz wheel than a calculator.Better tell me which airline they work for so I can avoid flying with it? Air France perhaps?

I've been an "engineer" all my life, and used the slide rule at school in the late 1960s so I am fully familiar with how it works. But that's where it belongs. No "engineer" I know uses one today. It's a multiplication/division device; that's all. The wind side of the aviation slide rules just does a geometric solution to the wind triangle, but you don't need to do that unless dead reckoning, which nobody does when flying somewhere "for real" today.

The reason we still have this antiquated device in the syllabus and in the exams is because the JAA material was finalised c. 1998, and was written by ex national Air Force navigators (and similar types) who were retired even before that date. Practically everybody who has been involved with today's ATPL exams had finished with aviation in all practical sense even before GPS came along in the late 1980s.

[mad_jock]

All of them will have a few :D

And we do use specialist slide rules when I worked as a mechnical engineer for working out loads and Ixx Iyy values of H beams, bolt loads etc on flanges. That was in 1998 and I can't see things changing much because it was a very quick easy way of getting the data you required. I still have my metric imperial converter for doing pressure pipe work for ASME codes.

Military use them for working out ranges, Artillery use them for firing solutions in case the electronics go tits up.

Slide rules arn't as dead as you think.