B777adiru/lrn
Our company is about to start Trans Atlantic Operations. However according to the literature I have read. We need a minimum of 2 operational Long Range Navigation systems. Apart from the ADIRU we also have 2 GPS receivers.
However there are a number of senior captains who say because the ADIRU consists of 3 IRS's we in fact have 3 Long Range Navigation (LRN)systems and that is all that is required. Unfortunately there is no literature from Boeing that states that the ADIRU consists of 3 IRS's. Further our MEL states at least 1 GPS receiver must be operational for MNPS ops.
I realise the MEL is the definitive document but could somebody please clarify the ADIRU and the 3 IRS's.