E-GPWS modes 1-4 with GPS deferred.
On your aircraft with GPS deferred are there any references in the MEL to E-GPWS accuracy in modes 1-4 for terrain avoidance?
In plain language, minus GPS, are the remaining nav inputs to the FMS you fly sufficient to provide position fixing to still be accurate to the same degree
Broken down even more, minus an obvious sign like a map shift, are you sure that E-GPWS terrain warning received is truly on your path of perhaps offset due to accuracy?
I know I will react as if it was, but curious if the accuracy minus GPS is addressed in your MEL.