Semi Circular Rule?

[Bundy]

Sorry for the misunderstanding on my part John

Again, yes it is direct north south routings that will always be a bit "hazy".....communication no less important though.

Apart from my mistake in training, where I totally misunderstood this rule, (hence the topic),... I have never since had to change to 1013 QNE because 1500ft agl is about 300-500ft higher than I normally cruise...

Dont really have a good answer to your question...I can see the danger you pointed out.

[John.com]

Sorry for the misunderstanding on my part John

Again, yes it is direct north south routings that will always be a bit "hazy".....communication no less important though.

Apart from my mistake in training, where I totally misunderstood this rule, (hence the topic),... I have never since had to change to 1013 QNE because 1500ft agl is about 300-500ft higher than I normally cruise...

Dont really have a good answer to your question...I can see the danger you pointed out.

Hi Alan,

I figured there was no better person to bounce this off than Jim Davis, so I PM'ed him today and, true to tradition, Jim was very quick to respond with this answer:

"Hi John, good to hear from you.

You are quite right - in the first example, 181 and 359 puts them both at Even +500, and the others are both at Odd+500. And remember they are based on MAGNETIC TRACK.

I understand that in Israel, which is a thin NS country, this problem was so frequent that they actually moved the split round 90 degrees so that it happens on the 090/270 axis.

Jim"

So, indeed, the semi-circle rule does become a concern when flying at the extreme 'edges' of the semi-circles!

I hope this helps!

Many thanks to Jim!

Safe Skies!

John.com