Originally Posted by Brain Potter
The Dominie is not operated under JAA regulations. It is a military aircraft operated under a MAR that allows operation by single pilot plus PA. The RAF 125 is regarded as a different type, but is still operated under a MAR (that requires 2 pilots) however it is similarly not subject to JAA regulations and can therefore be fitted with equipment that would preclude civil certification. The MoD can choose to operate to JAA regulations as a 'best practice' model but is responsible for certifying it's own ac under MAR and I don't believe that JAA has any regulatory over-sight of this process. This explains why, for example, some military transport ac do not have EGPWS, even though it has been a required fit by the JAA and it's pre-cursors for many years.
Absolutely right. This is because the military authorities have an airworthiness structure and regime that is held to be the equivalent of that administered by the CAA etc. Hence military aircraft operate under MAR, not (in general) JAA, although as you say, such matters may be taken into consideration and incorporated.