CRP-1
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CRP-1
Using the new Pooleys CRP-1 Computer is harder than I imagined. I have started reading through the Air Navigation Air Pilots Manual and was wondering if anyone could give me a hand using and understanding it, or, is anyone else in the same situation?
Thanks
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I found that "practice makes perfect" with ye olde flight computer. The more you use it the more you will become comfortable with its use and will learn more about it.
A couple of quick exercises you can do at the dining table that helped me.
Try drawing up a fictional cross-country on your chart and working out a plog. Try doing two or three different plogs, perhaps with varying wind speeds/directions.
Try doing basic division/multiplication using the CRP-1.
You will get better the more you use it.
Many don't like the CRP-1 or its equivelants, will tell you its out of date piffle and to use an electronic computer instead. Fair enough that's their opinion. But for the PPL you will need to learn how to use it whether you like it or not. I detested Algebra and solving equations at school but I had to do it because it was part of the syllabus, now I see its relevance however and appreciate it. Once you get to know it and become comfortable with its use you will appreciate its usefulness, I still use mine all the time.
Smithy
A couple of quick exercises you can do at the dining table that helped me.
Try drawing up a fictional cross-country on your chart and working out a plog. Try doing two or three different plogs, perhaps with varying wind speeds/directions.
Try doing basic division/multiplication using the CRP-1.
You will get better the more you use it.
Many don't like the CRP-1 or its equivelants, will tell you its out of date piffle and to use an electronic computer instead. Fair enough that's their opinion. But for the PPL you will need to learn how to use it whether you like it or not. I detested Algebra and solving equations at school but I had to do it because it was part of the syllabus, now I see its relevance however and appreciate it. Once you get to know it and become comfortable with its use you will appreciate its usefulness, I still use mine all the time.
Smithy
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The best ones have the windbar that makes life easier. ( Airtour over Pooleys any day )
When I started out we were always advised to go for a CRP-5 just in case the flight bug well and truley bit & you wanted to proceed up the training ladder.
Saves buying two CRP's in the long run. Also found the CRP "5's" feel more robust.
£90 upwards can be hard to swallow for a device that drives you mad but if you don't mind little used ones then ebay always has some aournd £30 or less.
crp 5 flight | eBay
Cheers
When I started out we were always advised to go for a CRP-5 just in case the flight bug well and truley bit & you wanted to proceed up the training ladder.
Saves buying two CRP's in the long run. Also found the CRP "5's" feel more robust.
£90 upwards can be hard to swallow for a device that drives you mad but if you don't mind little used ones then ebay always has some aournd £30 or less.
crp 5 flight | eBay
Cheers
Last edited by cjd_a320; 17th Sep 2011 at 22:13. Reason: Usual poor posting skills
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Tobster,
You're unfortunately of an age where you've not had to do much without electronic aids. The CRP-1 or any of the other flight computers are just circular slide rules on one side and triangle of velocity calculators on the other, neither of which feature much in what you've done in maths at school I fear.
I tend to find that students of your generation usually need shown how to use a CRP-1, rather than be left to follow the instructions that come with it. The APM or AFE books are a little better, as they have pictures, but you need the book and computer to be from the same company ideally, so the pictures match. I believe Pooley's now also do a CD or DVD, which should be better again, but I've not actually seen one.
Reading peoples written instructions off pprune, will probably be little better than what you have already tried. Maoraigh1 is right, get your instructor to show you how to use it. Did whichever club you're at really just sell you it and then send you off to figure it out on your own?
Or did you just buy an "everything you need for a PPL" package off the internet? Are you still in the ATC? don't they teach you that kind of stuff there, or at the very least somebody surely knows how to work a CRP. Alternatively, being a member of the gliding club at Walney, have you tried getting someone there to show you?
The CRP-1 is pretty simple and straightforward really, nothing very complicated at all, once you've been shown how that is. You will need to get your head round some imperial units and approximate conversion factors between metric and imperial units though.
You're unfortunately of an age where you've not had to do much without electronic aids. The CRP-1 or any of the other flight computers are just circular slide rules on one side and triangle of velocity calculators on the other, neither of which feature much in what you've done in maths at school I fear.
I tend to find that students of your generation usually need shown how to use a CRP-1, rather than be left to follow the instructions that come with it. The APM or AFE books are a little better, as they have pictures, but you need the book and computer to be from the same company ideally, so the pictures match. I believe Pooley's now also do a CD or DVD, which should be better again, but I've not actually seen one.
Reading peoples written instructions off pprune, will probably be little better than what you have already tried. Maoraigh1 is right, get your instructor to show you how to use it. Did whichever club you're at really just sell you it and then send you off to figure it out on your own?
Or did you just buy an "everything you need for a PPL" package off the internet? Are you still in the ATC? don't they teach you that kind of stuff there, or at the very least somebody surely knows how to work a CRP. Alternatively, being a member of the gliding club at Walney, have you tried getting someone there to show you?The CRP-1 is pretty simple and straightforward really, nothing very complicated at all, once you've been shown how that is. You will need to get your head round some imperial units and approximate conversion factors between metric and imperial units though.
Last edited by mrmum; 17th Sep 2011 at 21:54. Reason: spelling/punctuation
It's immensely helpful in the initial stages (and I find good practice afterwards) for the triangle of velocities calculations, to do a rough sketch on a piece of paper and derive an approximation. If the CRP (or equivalent from AFE or Transair) gives a very different answer, you did something wrong, and it's easier to see what you did wrong.
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I'd go with cjd a320 and buy the CRP5, Just the larger size makes it easier to use and understand. Do get some lessons, most schools have a huge one for demonstrations, but younger instructors, who haven't used old technology at schools seem to struggle to teach it properly. Get the oldest, greyest instructor at the school to help you.
Many people deride it, I've used it for 30 years and have yet to find a really good electronic version.
I keep one in my aeroplane and one in my briefcase for doing gross error checks on what the FMS in the day job "office" says.
SND
Many people deride it, I've used it for 30 years and have yet to find a really good electronic version.
I keep one in my aeroplane and one in my briefcase for doing gross error checks on what the FMS in the day job "office" says.
SND
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The CRP-5 paired with an ASA Pathfinder was our schools mantra.
The pathfinders to get used to electronic inputting & to double check your "wheel" skills.
Probably just coincidence the club sold both at a heavy mark up.
Ebay always got round that annoyance.
Plus in the vain world of the club's flight planning rooms, whipping out a CRP-5 & pathfinder from the flight case, used to carry more kudos than crp-1's.
Cheers
The pathfinders to get used to electronic inputting & to double check your "wheel" skills.
Probably just coincidence the club sold both at a heavy mark up.
Ebay always got round that annoyance.
Plus in the vain world of the club's flight planning rooms, whipping out a CRP-5 & pathfinder from the flight case, used to carry more kudos than crp-1's.
Cheers
Last edited by cjd_a320; 19th Sep 2011 at 17:32. Reason: Usual poor posting skills
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A few Pathfinders have copped up at less than a third of retail...
asa pathfinder | eBay
A CRP-5 + Pathfinder for less than a normal CRP-1 from the flight club's shop = Bonus
Cheers
asa pathfinder | eBay
A CRP-5 + Pathfinder for less than a normal CRP-1 from the flight club's shop = Bonus
Cheers
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Is the E6B just a platform clone of the ASA CX-1 ?
E6B Flight Computer by Sporty's - Sporty's Pilot Shop
asa cx- pathfinder | eBay
E6B Flight Computer by Sporty's - Sporty's Pilot Shop
asa cx- pathfinder | eBay
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This might sound a little complicated to anyone who doesn't understand the "Sine Rule" but with a little practice you'll be able to assess the required drift angle by a small amount of mental agility and that your cross-country navigation skills will become easy-peasy.
Firstly, using your CRP-5 (or whatever version you might have) calculate the “Maximum Drift Angle” that you will experience over the leg that you intend to navigate. On a typical UK X-Country flight you’ll not be too far out with the calculation using the maximum wind strength over the entire route. Use this as the basis of “maximum drift” and draw a line on your chart to indicate the generalised wind direction i.e. “maximum drift”. Similarly, calculate your “max groundspeed” with respect to the wind direction… an easy calculation! All of this can be done at the flight planning stage of your route.
At the commencement of your next navigation leg, compare the forecast wind-line to an imaginary line that passes through your longitudinal axis (nose to tail). Using the resultant angle, look at the clock-face of your watch and, if the wind is within 15 degrees of your longitudinal axis (fore or aft), it’s on the “quarter-hour”; therefore, use “1/4” of the “maximum drift angle” (it’s the Sine of 15 degrees i.e. 0.25). If the wind angle is within 30 degrees the Sine value (fore or aft) its 0.5; therefore, use half of the maximum drift value. If the wind angle is within 45 degrees (fore or aft) the Sine value is 0.707; therefore, use ¾ of the maximum drift angle. Beyond 45 degrees… use maximum drift!
Similarly, your groundspeed can easily be assessed in a similar manner. Calculate your maximum groundspeed and indicate this speed against the “max drift” line that you previously drew on your chart. This time… use the Sine of the angle with respect to the angle of the wind from an imaginary line drawn through the wings. If the wind is up to 15 degrees forward from the wing, subtract 1/4 of the wind component from your indicated airspeed; if it’s aft of the wing… add it! If the wind is up to 30 degrees forward of the wing, subtract ½ of the wind component (aft of the wing… add it). If the wind is up to 45 degrees forward of the wing, subtract ¾ of the wind component (aft of the wing… add it). More than 45 degrees forward of the wing, subtract ALL of the wind component (aft of the wing… add it).
Once that you get used to the arithmetical values associated with the wind direction/speed calculation you’ll very quickly be able to recalculate any diversion heading/groundspeed without recourse to the “whizz wheel”.
Complex as this might sound; it forms the very basis of the understanding of pilot navigation and that it takes the fear out of any en-route/diversion calculations that might be faced by a student pilot. Besides which… it will ease your workload by your not having to fumble around with your whizz wheel when that pesky examiner instructs you to divert to XYZ! Establish what you need to do and then… cross check with your whizz wheel when time permits! You’ll be surprised at how accurate your mental calculations can be!
Be safe; fly the aeroplane.
Regards
TCF
Firstly, using your CRP-5 (or whatever version you might have) calculate the “Maximum Drift Angle” that you will experience over the leg that you intend to navigate. On a typical UK X-Country flight you’ll not be too far out with the calculation using the maximum wind strength over the entire route. Use this as the basis of “maximum drift” and draw a line on your chart to indicate the generalised wind direction i.e. “maximum drift”. Similarly, calculate your “max groundspeed” with respect to the wind direction… an easy calculation! All of this can be done at the flight planning stage of your route.
At the commencement of your next navigation leg, compare the forecast wind-line to an imaginary line that passes through your longitudinal axis (nose to tail). Using the resultant angle, look at the clock-face of your watch and, if the wind is within 15 degrees of your longitudinal axis (fore or aft), it’s on the “quarter-hour”; therefore, use “1/4” of the “maximum drift angle” (it’s the Sine of 15 degrees i.e. 0.25). If the wind angle is within 30 degrees the Sine value (fore or aft) its 0.5; therefore, use half of the maximum drift value. If the wind angle is within 45 degrees (fore or aft) the Sine value is 0.707; therefore, use ¾ of the maximum drift angle. Beyond 45 degrees… use maximum drift!
Similarly, your groundspeed can easily be assessed in a similar manner. Calculate your maximum groundspeed and indicate this speed against the “max drift” line that you previously drew on your chart. This time… use the Sine of the angle with respect to the angle of the wind from an imaginary line drawn through the wings. If the wind is up to 15 degrees forward from the wing, subtract 1/4 of the wind component from your indicated airspeed; if it’s aft of the wing… add it! If the wind is up to 30 degrees forward of the wing, subtract ½ of the wind component (aft of the wing… add it). If the wind is up to 45 degrees forward of the wing, subtract ¾ of the wind component (aft of the wing… add it). More than 45 degrees forward of the wing, subtract ALL of the wind component (aft of the wing… add it).
Once that you get used to the arithmetical values associated with the wind direction/speed calculation you’ll very quickly be able to recalculate any diversion heading/groundspeed without recourse to the “whizz wheel”.
Complex as this might sound; it forms the very basis of the understanding of pilot navigation and that it takes the fear out of any en-route/diversion calculations that might be faced by a student pilot. Besides which… it will ease your workload by your not having to fumble around with your whizz wheel when that pesky examiner instructs you to divert to XYZ! Establish what you need to do and then… cross check with your whizz wheel when time permits! You’ll be surprised at how accurate your mental calculations can be!
Be safe; fly the aeroplane.
Regards
TCF
