Originally Posted by Dr Eckener
DFC,
MSA is 1000' above within 5nm of the aircraft, not 10nm as you state. Generally agree with most other comments you make, although you seem to have gone quiet on this one since FFF's comments.
The important word that I used is
indicated.
If you simply measure 5nm each side of track and check for obstacles then there is the posibility that you will be less than 5nm for the edge of the area checked because of system errors and you not flying to the exact mm on the chosen centerline. Thus 10nm allows for a maximum RNP5 enroute error.
Of course you could sit down with PANS-OPS and accurately calculate the errors and use the exact figures to reduce the area to be considdered.
As for FFF's comments - Annex 10 provided a clear black and white written statement that was at odds with what the Examminer said and at the time I said that it would be odd for an examminer to fail someone for using the BPL outside of the DOC while permitting / advocating using the LOC outside of the DOC. I am still waiting for those that claimed to have CAA advice regarding IMC minima being advisory to name names (as FFF did) or publish written evidence.
---------
What everyone regardless of position agrees on is that the whole thing is confusing. Thus I propose that it be re-written to a very simple statement;
"IMC rating holders in current practice shall add 300ft and 1000m to the applicable IR minima".
That would make the ILS (IR single pilot 200ft / 800m) a 500ft / 1800m IMC minima and the lowest possible. Everything else requiring higher DH / MDH and higher Visibility / RVR.
Any comments regarding that?
Regards,
DFC