the totally pointless CRP thing

[Ludwig]

Sitting in the club at the weekend whilst a Nav ground school was going on elsewehere in the building, I spoke to the instructor who was lamenting that a whole morning had been taken up on the crp thingy. Now, somewhere there must be a heap of these things junked the moment the exams have been passed, only reserected by those going on to more exams. No one it seems uses them in anger. In these days of calculators, they should be dumped. Ok they are clever, but they are a total waste of time money and effort and add nothing to flight safety.

What thinketh thou fellow ppruners, does anyone use these things?

[Genghis the Engineer]

Regularly, particularly if flying a lower speed aeroplane - or pretty much anything at altitude, where drift can be quite significant.

But it is noticeable how many of them are usually for sale on eBay.

G

[Aussie Andy]

there must be a heap of these things junked the moment the exams have been passed

No way! I love using it, and do so most times I fly, unless its circuits or local area I am very familiar with! The other exception is when I just use mental DR to estimate correction angle based on max drift - but this is generally when there are two PPLs in the cockpit and the workload is reduced.

Why don't people like them? They are easy to use (if you learn!), fast, flexible (in that they can be used for a variety of problems), they help you to visualise vector problems, and they are safer in that you can - again assuming you understand how they work - readily spot gross errors (versus a calculator on which you might simply mis-key one operand or operator and hence get a wrong answer).

Anyway, I suppose the question wasn't whether I like using nav computers and why, but was rather whether people do use them after training: I do at least

Andy

[Cusco]

Agree entirely: dump them: They hark back to the days of slide rules and logarithm tables I used to struggle though O level maths (that's how old I am.)

I haven't used mine for 8 years: that's not to say I don't work out the wind drift factor every time I fly significant distances, I do ( though I know a few peeps who fly Arrers who don't bother) but I use the asa flight calculator, and yes I keep a spare set of batteries in my flight bag.

These days when most GPS have a calculator function too I really can't see the need for the CRP.


Ducks head below parapet.

Safe flying

Cusco

[Aussie Andy]

But don't you guys think its valuable in the training scenario that everyone learns the same way, on the same device, and that it is one on which the vector problems can be visualised easily? Fair enough, we're all big boys and girls, and can decide on other techniques after training, but I think its good to have a consistent approach used in training so wouldn't want to see this changed. Would be interested to hear what an instructor thinks?

Andy

[DRJAD]

Well, I'm a new PPL holder, so perhaps my opinion doesn't count too much...

Anway, I've just sold two CRP-1s, but that's only because I have a CRP-5 now.

I actually enjoy using it - but I'm not anti-technology. I have a flight calculator, too, and use it for rapidity when the time matters. Prefer using the CRP-x though - as people say, it assists visualization of the problem and its solution when vectors are involved. It also forces a mental estimate of the order of the correct answer to all calculations - so one is mentally undertaking an automatic check of the sense of the calculation.

Mind you, I also enjoy working out crosswind components by multiplying the crosswind velocity by the sine of the crosswind angle, etc., - I know its sad, but, as a musician, I enjoy maths.!

[FlyingForFun]

Much easier to use than remembering lots of formulae. Not as accurate as a calculator, but far more accurate than you need in practical terms. I use mine every time I fly away from the local area.

FFF
------------

[gasax]

Still in my flight bag and used now and then. Just try finding the right menu on the Skymap and keying in all the data, just so it can tell you what the wind aloft is......

Mind you the track made good versus required is even easier. Maybe that's the issue!

[Flying Boat]

Always use mine too, the CRP5 & 1, but never got near the 300kts compressibility point in a PA-28, something to do with VNE.

Never had to change the batteries in 7 years of using the CRP1, and it has never had a programming glitch giving eroneous output.

There are some things you can do with a CRP quicker than a calc, such as fuel weight.

It also doubles as an efficient fan on a hot day, Casio are still to market the Calcufan.

[High Wing Drifter]

Even if you have a calculation that is made up of a series of smaller mults and divs it is a doodle! You can just string the numbers together to get the right result about 10x faster than using even a pocket calculator! Just as an egg timer makes a create nav clock, so a CRP is great at getting the flour right in the kitchen

If only there was a way for CRPs to be able to do the balance calcs too, then one tool would fit all

[mad_jock]

And also the ruler bit of it is a good straight edge.

You can scratch your back with the ruler bit if it gets itchy in the air.

And also the ruler bit can be used to lift the ring pull on a can of beer if you can't get your finger under it.

MJ

[jonnys]

Agree wholeheartedly with Aussie Andy, long live the CRP!!

Used mine since passing PPL, certainly allows you to visualise the flight more easily and keeps one in touch with a little piece of aviation history! (Great as a can opener and back scratcher aswell, must agree...hell, I'm gonna get my moneys worth, why fork out £70 for an electronic calculator when the CRP can do the same job? May aswell have an hour in a 152 instead!)

[Tall_guy_in_a_152]

My E6B (Aluminium equivalent of CRP) has never been quite the same since my instructor man-handled a C-152 over it. Important lesson: never leave your flight bag unattended next to an aircraft. Luckily my headset was in the cockpit.

Anyway, it still works even with a crease up the middle. I use it mainly for conversions (gallons of fuel to pounds weight etc). I use a fairly ancient ('82 vintage) programmable calculator to do my wind calcs for the flight plan. I type in the wind and then each leg and it spits out the course to fly and ground speed. At the end it shows total distance and an estimate of fuel burn (always double checked, if marginal!).

The only problem is that every time the battery runs out (every 18 months or so) it forgets the program, so I have to type it all in again. Then I have to remember how to use the E6B so that I can cross-check a few wind / track combniations to check it still works. All good revision, I suppose.

If anyone would like a copy of the BASIC program that does all this, then feel free to PM me!

TG.

[Keef]

Still got mine. It's in the flight bag. I take it along for checkrides and the like, but happily I'm not asked to drive it. I think I still could. I hope...

I use the Jeppesen calculator for serious flying, except when I do the plog on the PC before setting out (Excel does it all for me, then) I suppose if my battery ran out en route...

I've still got my old O-Level slide rule, too (the trusty "Universal II") and don't use that either.

[mad_jock]

Now i sem to remember my dads Universal II he still measures energy in ergs what ever they are.

The Universal II would make a quality back sratcher in the cockpit.

MJ

[KCDW]

Use it every time I fly (except circuits). Only thing I don’t like about it, is figuring out the TAS – the pressure alt and temperature gauges are so small, and the increments so large, it’s easy to be off quite a bit, if you’re not careful.

But the best bit is when you show it to a prospective new passenger – they look at it, look at the bashed up old rental you’re about to get into, and generally shake their head in disbelief

[bookworm]

I'm still trying to find a situation in which the level of precision required for a calculation is exact enough to preclude doing it in one's head but slack enough not to justify a flight planning program or spreadsheet. When I find one, I'll try the CRP-1, which I only dust off when I forget conversion factors and the like.

[QNH 1013]

Like all slide rules, the CRP computers will do conversions much quicker and easier than a calculator...

When you are next shopping in foreign parts, set the value of the Euro (or whatever) on the inner scale, hold it in your hand while looking at the items on the shelf and you can read off the exact price in real money instantly. With a calculator, you have to punch in the shelf price each time to get the answer. With a slide rule, you just look and the answer is there.

I can't imagine ever selling my CRP while I'm still flying.

[BEagle]

I normally use MDR, but occasionally a mini-Dalton Computer Dead Reckoning Mk 5A for conversions. Also the TAS function for my heavier metal theoretical stuff.

The Nintendoverts of the play station generation can keep their electronic ones! And I say that having bought my first electronic calculator (Prinztronic Micro) in 1972 for 49 guineas. Still going strong - but it uses 0.5W of power from 4 AA batteries. Must be a collector's item by now!

[KCDW]

Hmm... can't imagine walking around a shopping mall in France with one in my hand though