B737-700
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Flight Crew Type 15000
Confusion; Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Chart Or Publication; Human Factors
Flight to OAK listed SJC as an alternate due to low ceiling and visibility in OAK (700/4). I checked the NOTAMS for SJC and noticed that the RNP Z Runway 30L had two NOTAMS listed that raised the approach DA (Decision Altitude)/HAT (Height above Terrain) for .15 RNP approaches; but the two NOTAMS were not the same. FDC 8/3608 raised the DA to 446 ft. and FDC 8/7886 raised the DA to 674 ft. Today's date was within the valid dates of BOTH NOTAMS. Unless I misread some of the details; there should only be 1 NOTAM that changes DA/HAT for a given date; giving rise to confusion as to which NOTAM applied. The conservative course of action would be to fly the higher minimums of 674 ft. DA. The system which we use for NOTAMS should ensure only 1 NOTAM is listed to avoid conflicts such as this.
B737-700 Captain reported the Decision Altitude for the RNP Z runway 30L increased to two different values after two different NOTAMS were applied.