MDA
Apologies if this has been discussed before.
Does anybody out there believe that it is permissible to go below MDA when not visual and conducting a missed approach from a NPA?
I am aware that many operators add an amount (around 50') to the published MDA and treat it as a DH. In this case the aircraft will not go below the actual MDA.
I am also aware of at least one operator that states in its ops manual that you can initiate the missed approach at MDA. This clearly results in the aircraft going below it.
Just to clarify this question relates only to a "traditional" NPA not a LNAV/VNAV approach with a DA published.
An authoritative reference showing the acceptability of this practice would be appreciated.