CRP5 Questions

[bobster1]

You can use what you want..but the atpl exam answers have been calculated using the CRP-5, so we have been told, there is slight differences in calcs using other manufactures flight computers..good luck!!

[AndrewOO]

Thank you.

I am sure that aviation examiners know that there are slight variations in aviation physical constants throughout the world, and aviation being an international issue would take this into consideration. I am also sure that the examiners are aware that different types of aviation computers are available, and take this into consideration in their answers, when it comes to a written paper. On a multiple choice question/answer the correct answer can be derived from rounding numbers. What I was looking for is if there is a difference in the physical quantities calculated by the E6-B, and CRP-5, that would retard my answer, and choose the best accordingly. If they both calculate the same things, I will get an E6-B.

Andrew.

[EchoMike]

CRP-5 & E-6B differences

E-6B doesn't do specific gravity, it assumes gasoline weighs 6 lbs per US gallon. CRP-5 does, you can use local value, but it is usually .726 or so for avgas, Jet-A is about .8. The CRP-5 will also give you fuel weight in kg in one calculation.

Ergo, CRP-5 can be used for any airplane, anywhere, E-6B is best for piston engine airplanes in USA, but still usable anywhere else.

Accuracy is about the same - the larger CRP-5 makes it slightly easier to read, but remember the real-world figures you base your calculations on may not be totally accurate to start - the 8 GPH might actually be 7.9 or 8.1, the 20kt wind could easily be 15 to 25, and so on.

E-6Bs are much less expensive, as cheap as $12.00, made of the finest grade of aviation rated cardboard - aluminum ones are about $30, and with most of the E-6Bs, the *instructions are printed right on them!!!!* which is a brilliant idea!

The "instruction booklets" are awful and will make you want to take up surfing instead of aviation . . .

I teach this stuff in ground school - a little practice makes it easy.

Best Regards,

Echo Mike

[AndrewOO]

Thanks Mike.

I will get both, now I hope a PA-28, C-172, C-152 is the same in Nairobi, as Prague, London, Miami, Tokyo, or Sydney.

Andrew.

[Tinstaafl]

I just can't work out why the UK is so anti-'CR's'. People in the UK just ignore them yet they're at least as accurate (even more so, in my experience) compared to the CRPs that are so popular in the UK. Some problems even require fewer steps to calculate using a Jepp. or ASA CR computer compared to the CRP.

[AndrewOO]

I guess with the E6-B, CRP-5, and a navigation plotter most if not all Flight planning, and navigation general aviation tasks can be done, which in an airline scenario is done by professional flight planning software, addition of the CRs would probably complicate tasks to be done by a GA pilot. I have finally decided to settle for one of the FAA approved electronic E6-Bs, and a UK CRP-5, together with some sort of professional flight planning software, with an international database.

Thank you.

Andrew.

[BlueRobin]

The critical difference iirc is the lack of a Mach No Index.

If you are looking to save a few bob for JAA ATPL by gettgin an E6B, don't. You need the CRP-5, or equivalent spec.

[AndrewOO]

What I actually want is to be able to seal, and open a flight safely. So my concerns are my abilities to do that with the right tools, but that is another topic. In conclusion I will get an Electronic E6-B to be used to cross check my manual calculations with the CPR-5, and other navigation calculations. I believe the German Aviation authorities allow the Electronic E6-B for their JAA exams. Like wise I expect to get Professional Flight planing software that covers my region of aviation activity to cross reference the manual flight data.

Thank you all.

Andrew.

[frodegh]

Hi!

The CRP manual tells you to use wind UP for questions on heading and wind DOWN for questions on track. So far that has worked 100% for me, with questions from bristol/atponline.gs. It makes sense as well, if the CAA use CRP as reference.

Blueskyrich's problem doesn't match though. Using wind-up gives the correct speeds, but considering the question gives headings, and not tracks, wind-down should be used according to CRP manual.

I'll definately be going with UP for headings and DOWN for tracks on my exam next week, but will try both if I don't get a good match (unless the alternatives give it away).

Anyway, here's a quick walkthrough of the two methods
Find heading/gs: Mark wind upwards, set track, set TAS on wind mark, read GS in center, read WCA.
Find track/gs: Mark wind downwards, set heading, set TAS in center, read GS at wind mark, read drift angle.

And by the way, either method gives the same results on both E6B and CRP models. You just need to look away from the detailed wind-up description on a E6B when doing questions on track.

I would never do the exams with an E6B though, as it lacks the high speed side, the mach conversions and more.

Edit: Just tried with some of the "Find w/v" questions on atponline.gs as well (where you have both hdg and track). Answers are a little off with wind up, and match perfectly with wind down.

[Jaguar Pilot]

Does anyone here know that the"CRP" in CRP5 or CRP1 stands for "Computer Robert Pooley"?

It is an entrepreneurial and commercial adaptation of the original RAF Dalton navigation computer (the aluminium one which does not warp in sunshine). Both are simply analogue slide rulers.

May I assure you that the questions in the JAA question bank allow for production errors/tolerances in all navigation computers so that, providing you use correct techniques, there is no way that you can derive an incorrect answer.

Since this is my profession, I just thought I would mention it.......

...and long live the Flight Management Computer! This is free of charge and comes ready-installed in your jet.

[paco]

The E-6B was developed in the United States by Naval Lt. Philip Dalton in the late 1930s. The name comes from its original part number for the US Army Air Corps in World War II.

I took to the Jeppesen one as soon as I saw it and have not used anything else since, including on my exams, although the small one is kinda hard to read at night. I can also recommend the AFE product as a better precision instrument than the CRP-5

Phil

[HappyFran]

What happens to old CRP 5

I'm at the beginning of ATPL, been told I need a CRP 5
Clever it may be, but £75.00 WHOWW

What happens to the old CRP 5 when all you fATPL's get snapped up and whisked away to play on shiny new jets with built in calculators ???

Does anyone have a much loved but used one they are willing to re-house (for a reasonable consideration) to a somewhat impoverished, but loving home ??

[AndrewOO]

Actually on most flight lines flight planning is done for flight crew by administration flight ground crew. There are specialized flight planning organizations, and software that can do this for you, as well. This simply increases pilot comfort and safety, by the reducing the burden on a pilot. But if you fly a Charter, Corporate, Private(Yes some Private Pilots have ATPLSs) aircraft you will find that you have to do the flight planning yourself much of the time, and a CRP5, E6B will be a very useful tool. Navigation, and flight planning are syllabus requirements every-where as they help you understand, and compute flight issues, and solutions, so a CRP5, or E6B are a requirement. Without a CRP5 or E6B you will be reduced to using a slide-rule, paper and pencil, and I assure you will be frustrated, and make endless mistakes. When you get to your ATPL jet may find you still enjoy spending an hour or two at home before an international flight doing flight planing calculations to cross check with your flight line ground crew. When you will have finished, you would probably throw your own calculations, and CRP5(E6B) into your flight bag, and head for the airport for the flight.

[Eavr]

CRP-5 Online Course

If someone is looking for a course on how to use a CRP5 flight computer I found this course very useful. It is called "How To Use the CRP-5 Flight Computer and Smash the Exams" and is free. Hope that helps.
https://www.udemy.com/crp5course/