Thanks John,

The slightly misaligned TAS is noted and agreed on the manual ... it is not great to say the least.

When you say "clones" is there a better device to get?

My logic is simply that I started with placing the 186 heading T (given) on TC and then added 11 degrees based on the 11 degrees crab angle obtained (19 kt right cross wind) which is 186 + 11 = 197 degrees T

Thanks for your help

When you say "clones" is there a better device to get?

First, does yours have a problem ? On the calc side, line up the outer scales (C/D scales) so that 10 is against 10. Read around. All the various numbers should be aligned similarly. Then set, say 10 against 20. Read around. All the various numbers should be aligned in the ratio 2:1, so 10 is against 20, 20 is against 40 and so on. The extent to which there is misalignment indicates the extent of any manufacturing problems. The same needs to be done with the look up table cutouts but that gets a bit involved. Similarly, on the nav side one can set the TAS symbol against the 10 (this is the same as 10 against 10 on the other side) and check a few sine and cosine values around the scales. Probably a bit involved for most. Unless the misalignment is significant, probably all is OK as we are looking at the device being reasonably fit for purpose rather than being an accurate slide rule such as we had in previous years at a greater cost of ownership.

My logic is simply that I started with placing the 186 heading T (given) on TC and then added 11 degrees based on the 11 degrees crab angle obtained (19 kt right cross wind) which is 186 + 11 = 197 degrees T

Was not the 186 value your track, rather than heading ? What does the TC stand for ? What is the significance of your 197 ? Perhaps have a quick revisit of the calculations ?

Thanks I will check my device for accuracy

186 is the track yes - apologies used the wrong term
TC - True Course on the CR-3 wind side
197 is the TC after adjustment by the 11 degrees crab angle

So in more detail ...

For Magnetic course
1. Place the 186 degrees True FPT (given) on TC on the green disk
2. Read cross-wind component of 19 kt right at 274 degrees True
3. Find 19 on the outer scale of the computer and read 11 degrees crab angle below it
4. Adjust the inside scale from 186 degrees by 11 degrees by moving the disk left until 197 degrees is on TC
5. Now adjust by the Magnetic variation by deducting 13 degrees to get final answer

For speed
1. As the crab angle is 11 degrees, find 11 degrees on the effective TAS scale and read a TAS of 98 kt
2. Deduct the headwind component (5 in my case) from the effective TAS to get 93 kt

186 is the track yes - apologies used the wrong term

All OK.

TC - True Course

That's US-speak for our "track"

197 is the TC after adjustment by the 11 degrees crab angle

Not quite. 197 is track corrected for drift to end up with heading.

adjust the inside scale from 186 degrees by 11 degrees by moving the disk left until 197 degrees is on TC

No. TC has naught to do with headings, it is track. You leave 186 against TC and note the heading somewhere else for the direction in which you need to point the aircraft. When you put 186 back against TC, what does your W/C become ?

One needs to keep in mind that the CR does its calculations along the TR/GS vector which is why folks get all confused by ETAS and why ETAS has nothing at all to do with the Dalton's solution, despite widespread common belief to the contrary. When you read, or someone tries to tell you that the Dalton somehow attends to ETAS in the background (or some similar nonsense), just smile sweetly and knowingly while shaking your head.