Avoiding Controlled Airspace
 

Looking for the AIP reference for avoiding controlled airspace when using the NDB.

From memory it was a tolerance of 6.9 degrees.

I cannot find any reference to it in the AIP, but I have done the latest amendments!

My last record of the tolerances is in my old AIP, ENR 1.1 19.11 Avoiding Controlled Airspace - page dated 25 NOV 04 and in the index last updated 23 NOV 2006. It is in my VFR Guide of 2001, but there is no mention in the VFR Guide from 2007 on.

So I would say this happened about 10 years ago for some unknown reason. You are correct though - the tolerance for the NDB was +/-6.9 degrees.

I still use the Visual tolerance of +/- 1NM buffer when navigating around a CTA boundary.

Non existent anymore. If you look up the reference for Avoiding Controlled Airspace in the AIP (ENR 1.1-45 para 4.1.12) you will find that it simply says that you must not enter CTA without a clearance and if you do not intend to ask for a clearance, then you should make sure that you do not enter CTA. I find it difficult to believe that anyone in CASA came up with this unassisted!

:hmm:

Those tolerances appears to have vanished after the 13NOV14 edition.

It's not quite as simple as just "1 mile."

When operating VFR in Class E or G airspace, the following tolerances must be applied to the planned tracks in order to avoid controlled airspace or restricted areas:

1-2000 AGL +/- 1 nm (day) +/-2 nm (night)
2000-5000AGL +/- 2 nm (day) +/- 3nm (night)
5001-10000AGL +/- 4 nm (day) +/-5 nm (night)

From 10001 to FL200 all VFR aircraft should apply +/- 8 nm

I think you’ll find that AIP used to say that. I think you’ll find that the rule is now simply: Stay outside unless you have a clearance (or there is an emergency).

1mm outside is now enough to comply with the rule.

It would be fascinating to drill down on that old 6.9 degree clearance buffer and find out how the hell did it ever see the light of day?

What greater mind of middle ages thought that whilst one was drilling their way through a turbulent cloud mass that one could measure decimal points on the ADF.

What was so alien about the concept of a round number that had whoever locked into the mindset that it had to be 6.9 not 7.0 or better yet 10.

This alone is enough to take the entire legal workings from this department and throw the lot over ones shoulder and come up with your own rule based system.

It was in the VFG some time back as I wrote above. Am assuming it's gone now if there is a current VFG these days.

Thank for the assistance Ppruners, greatly appreciated.

Obidah, I have always wondered likewise how you could track so accurately on a fixed card ADF in turbulence or heavy rain!

Probably like setting 23.2”MAP on the Seagull MKV for the CPLfinal exam.