Professional Pilot Training (includes ground studies) A forum for those on the steep path to that coveted professional licence. Whether studying for the written exams, training for the flight tests or building experience here's where you can hang out.

Question with the CRP-5 Windarm edition

Old 15th Oct 2020, 11:24
  #1 (permalink)  
Thread Starter
 
Join Date: Oct 2019
Location: Denmark
Posts: 7
Lightbulb Question with the CRP-5 Windarm edition

Hello, again dear pilots, I finally got my PPL and have a lot of hours to fly out alone, and I am about to put my full focus on ATPL. The first subjects I want to pass are Navigation, meteorology and Human performance.

I have a question about the CRP-5 Wind-arm edition that i can't find anywhere on the internet. I bought the wind-arm edition, because it is better for me, and it does not get so much weared, when you write on it and delete it with your eraser all the time.

The problem is that the ATPL books only explain using the CRP 5 without the wind-arm. I can 90% of the things on it, but there is one thing i never found out.

It is when you for example have a task like this one:
TH: 100 degrees
Wind speed: 30 kt
Wind direction: 170 degrees
TAS: 150 kt

How can I find the true track, giving this information? WIth CRP-5 Wind-Arm.
I have pounded my head on it for hours and failed every time and I tried youtube etc, but can't find it anywhere.

Thanks in advance.
math341c is offline  
Old 15th Oct 2020, 14:52
  #2 (permalink)  

 
Join Date: Nov 2000
Location: White Waltham, Prestwick & Calgary
Age: 68
Posts: 3,842
Why don't you get the Jeppesen CR-3 or the E6B circular comnputer. Much easier and you can do convergency and grid on it.

paco is offline  
Old 15th Oct 2020, 17:24
  #3 (permalink)  
Thread Starter
 
Join Date: Oct 2019
Location: Denmark
Posts: 7
Because you are only allowed to have the CRP-5/W at the EASA ATPL exam.
math341c is offline  
Old 15th Oct 2020, 18:20
  #4 (permalink)  
 
Join Date: Jan 2018
Location: Amantido
Posts: 490
The CRP-5 should be renamed CRaP-5. What a piece of junk.
As Paco said, the CR-3 or ASA current offering are so much better.
Banana Joe is online now  
Old 16th Oct 2020, 05:50
  #5 (permalink)  

 
Join Date: Nov 2000
Location: White Waltham, Prestwick & Calgary
Age: 68
Posts: 3,842
You might want to petition for its use - we had to do that with the CAA here
paco is offline  
Old 16th Oct 2020, 07:24
  #6 (permalink)  
Thread Starter
 
Join Date: Oct 2019
Location: Denmark
Posts: 7
Can you elaborate ?

What petition? EASA is not some democratic organization where we students can dictate what flight computers we may use for the exams.

They have a complete list of what you exactly may/may not use for the ATPL Exams.
math341c is offline  
Old 16th Oct 2020, 10:24
  #7 (permalink)  
 
Join Date: Feb 2000
Location: UK
Posts: 13,805
Originally Posted by math341c View Post
Because you are only allowed to have the CRP-5/W at the EASA ATPL exam.
Untrue. I used an Aviat 617, with no difficulty, and passed.

They all work basically the same anyhow, just slight variations like constants, Mach window or a wind arm.

Genghis the Engineer is offline  
Old 16th Oct 2020, 10:25
  #8 (permalink)  
 
Join Date: Feb 2000
Location: UK
Posts: 13,805
math341c

Where you'd have previously marked something with soft pencil on the facia, turn the wind arm to that position and note where on the scale it is, then use that point.

All else remains the same.
Genghis the Engineer is offline  
Old 16th Oct 2020, 14:50
  #9 (permalink)  

 
Join Date: Nov 2000
Location: White Waltham, Prestwick & Calgary
Age: 68
Posts: 3,842
It is up to each country as to what they use - EASA does not really dictate. We (as a school) requested that the UK CAA allowed the use of the CR-3.
paco is offline  
Old 16th Oct 2020, 16:33
  #10 (permalink)  
 
Join Date: Jan 2018
Location: Amantido
Posts: 490
Where I sat my ATPL exams everybody used the E6B, if you did not have one with you this is what the inspectors would give you. I had no issues with my CR-3.
Banana Joe is online now  
Old 20th Oct 2020, 22:26
  #11 (permalink)  
 
Join Date: Dec 1998
Location: Escapee from Ultima Thule
Posts: 4,259
Where did you get the idea that only the CRP5 is permitted? The UK's CAA website states:

"Approved flight computers – CRP-1; CRP-5/CR-3/CR-6; ARC-2; E6B"
Tinstaafl is offline  
Old 21st Oct 2020, 06:05
  #12 (permalink)  

 
Join Date: Nov 2000
Location: White Waltham, Prestwick & Calgary
Age: 68
Posts: 3,842
Apparently in Norway at least you have to use what they give you
paco is offline  
Old 27th Oct 2020, 15:52
  #13 (permalink)  
Thread Starter
 
Join Date: Oct 2019
Location: Denmark
Posts: 7
Hello again guys, I found a solution. I searched and searched for hours and finally found a video on how to solve for Track and GS with the CRP-5 Wind arm edition.

And I do not agree, CRP-5 is not crap, it's very effective. A circular flight computer is completely unnecessary and would be a waste of money. CRP-5 or CRP-5W is all you need for EASA ATPL.

Question banks and ATPL books use the CRP-5 When explaining the calculations of the different things, so I am pretty sure that the CRP-5 Is the main flight computer that is used for ATPL exams.

Take care
math341c is offline  
Old 27th Oct 2020, 20:12
  #14 (permalink)  
 
Join Date: Jan 2018
Location: Amantido
Posts: 490
You haven't even started and you don't know what you're talking about. With the CR-3 I could answer some questions in Radio Navigation or General Navigation that otherwise would require some calculation. Definitely not a waste of money, considering the price of the CR-3 and the over price of the CRP-5. Waste 80 I've ever spent. The CR-3 was just 25 euro.

Last edited by Banana Joe; 28th Oct 2020 at 07:09.
Banana Joe is online now  
Old 28th Oct 2020, 06:49
  #15 (permalink)  

 
Join Date: Nov 2000
Location: White Waltham, Prestwick & Calgary
Age: 68
Posts: 3,842
What Banana Joe said - I've seen how they make the crap 5

Before JAA the UK CAA used three of them to check the answers in their questions as the quality was so variable.
paco is offline  
Old 28th Oct 2020, 07:27
  #16 (permalink)  
Thread Starter
 
Join Date: Oct 2019
Location: Denmark
Posts: 7
Paco could you please elaborate what type of things the circular computer can calculate compared to the CRP-5?


BTW the CR-3 you are both talking about, at least the Pooley's one. Seems to be made for American pilots, as I can't not find it in any european store.

I can't not even find it on transair, i can only find the E6B Circular computer, is is the same as the CR3?
math341c is offline  
Old 28th Oct 2020, 12:18
  #17 (permalink)  

 
Join Date: Nov 2000
Location: White Waltham, Prestwick & Calgary
Age: 68
Posts: 3,842
The E6B circular is a clone of the CR-3 which isn't made any more.

You can do grid and convergency for one thing, time to station. The slide rule is pretty much the same with a more elegant solution for conversions.

http://www.captonline.com/CR3.jpg

As an example for convergency, say from York (roughly 54N), you need to find a ship just East of the Isle Of Man, which is more or less on the same latitude, but 3 to the West, or 180 minutes, which at the Equator would be 180 nm. The black band represents cosines, which stop at 45, but the cosine of 54 is the same as the sine of 36 so, looking opposite, you have 106 nm to go.

For grid, at 40W, a true track of 50 degs makes for a grid track of 90 and vice versa (just treat it like variation):
http://www.captonline.com/easagrid1.jpg

Phil

Last edited by paco; 28th Oct 2020 at 12:41.
paco is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.