CRM vs. OAS 2

25.10.2004

Submission:

I.W. is quite correct. The CRM was developed by optically tracking a number of airline aircraft whilst they were flying ILS approaches. This resulted in a refinement of the "crude" OAS surfaces based on a probability of collision. I recall the approach sample rate was surprisingly small, but the final mathematical modelling may have taken that into account. It appears to have worked OK for quite a long time! I always like to emphasise to pilots, though, that more than a half scale deflection of glide-slope or azimuth will put the aircraft in a position where the CRM modelling is close to being compromised. I guess that's why they're called precision approaches...

Jerry Willmott College of Aviation, Western Michigan University

Answer or Commentary:

(I.W. Due to my ignorance I will ask the question that I know most people are afraid to ask: -

Which is correct the OAS or the CRM?

If the CRM is correct then with modern computer technology we (procedure specialists) could design a 3-D computerised model of the CRM. To do this it is required to know the actual mathematical formulae that were involved in the CRM creation.

Does any body know the answer to this one?)