Avoman,
I trust that all of your compass swings are in order.
Thats not the point.
If you swung the compass in my aircraft I would not expect you to simply leave a note saying deviation -2 degrees as it is open to mis-interpretation as this thread has shown (Even if only by me!!).
All of the deviation cards I have seen say something like for 180 steer 178 etc.
This is unambiguous and easy to follow.
As I said earlier, the answer you get to the question posed depends how you read the question.
Before everyone shoots me down in flames as the lone voice against the world let me explain.
Crons original post said the answer was given as B : 25W.
He also said he made the answer A : 21W. Everyone else agreed that 21W was the answer, however I pointed out that depending how you read the question you can indeed get the answer 25W.
The difference is based on how you interpret the -2 degree deviation. Everyone seems to think that it means 2 degrees west. However the question doesn't say 2 degrees west is says simply -2 degrees.
(If it did say 2 degrees West then I think everyone agrees that the answer would be 21W).
Before you all groan please read on.
If my compass card says for 180 steer 178 I hope you would agree that my compass is underreading by 2 degrees.
i.e. my compass deviation is -2 degrees as deviation always refers to the compass as it is has deviated from magnetic by the given amount. (You cannot say that magnetic has deviated from your compass).
In the question it states deviation -2 degrees. I read this as above i.e. the compass has deviated by 2 degrees less than magnetic i.e. it is underreading by 2 degrees.
Therefore a compass reading of 195 is actually 197 magnetic, hence the answer calculates to 25W.
(equivalent to above i.e. for 197 steer 195).
To get 21W as the answer you must interpret the -2 degrees deviation to mean something different to my explanation.
It depends on whether you read the question as given as I did, or apply your interpretation of the -2 degrees to mean plus 2 degrees West
Regards
EddieHeli