[QUOTE]Mayday = imminent danger = emergency = PIC can do whatever he deems necessary./QUOTE]
I understand you are tying captains emergency authority to the concept of "imminent danger" and hence to MAYDAY on the basis of the inclusion of this phrase in the annex definition, and therefore any deviation from a clearance is a mandatory MAYDAY. I think you are extrapolating across two rules in a manner not necessarily intended by the writers. However it is not a bad interpretation in principle.
Your original post stated that you cannot declare an emergency with a PAN call. Allowing you the benefit of the doubt in the deviation from clearance case, there is nothing in the PAN call definition which would exclude it from being used to declare an emergency in other situations.
I don't suggest I wouldn't use a MAYDAY without the slightest hesitation. My point is that pilots should not feel any inhibition in using whichever phrase they think is most appropriate for their situation. After all an engine failure on a twin does not necessarily mean you will have to deviate from a clearance. In that case the preceding arguments would not be relevant.
Last edited by HPSOV L; 14th Dec 2014 at 20:13.