love the references to ILS v. NDB and "safer", just another example of lack of knowledge of procedure design parameters, and the part played by probabilities.
You jave gotta be freakin mad...establish quality system procedures and 95% confidence levels....Leadsled, I would love to be right seat when you give your approach brief....I have a 95% confidence that the data presented by my equipment is of a high enough integrity level to give us a very high probability of intercepting and maintaining an uncorrupted glideslope. Upon reaching minima of x feet I will look up and if there is a very low probability of actually visualising the surrounds of the runway that I have interpolated my approach around the hysterisis of the guidance wave...if this is actually the case that it is proven the probability of locating said runway is unlikly as in less than 50% confidence I will then call "data is corrupt" and proceed to then have a 95% confidence level that all four Rolls Royce RB211's will actually spool up to rated power that can be expected on 95% confidence level of uncorrupted data that power will be restored.......
Word for word 2.1 Aeronautical data
2.1.2 Contracting states shall ensure that integrity of aeronautical data is maintained throughout the data process from survey/origin to the next intended user. Aeronautical data integrity requirments shall be based upon the potential risk resulting from the corruption of data and upon the use to which the data item is put. Consequently, the following classification and data integrity level shall apply;
a) critical data integrity level 1x10-8 there is a high probability when using corrupted critical data that the continued safe flight and landing of an aircraft would be severly at risk with the potential for catastrophy
b) essential data, integrity level 1x10-5: there is a low probability when using corrupted essential data that the continued safe flight and landing of an aircraft would be severely at risk with the potential for catastrophy; and
c) routine data, integrity level 1x10-3; there is a very low probability when using corrupted routine data that the continued safe flight and landing of an aircraft would be severly at risk with the potential for catastrophy.
Leadsled...this is quality control for data!
Everything else is designed to a tolerance far greater than can be achieved by on board navigation equipment. I do not understand your interpretation of tolerance inclusion in the design of minima and "probability"
Just show me the quote in Annex 14 that says the design of an approach has a probability level of "X" and I will shut up.