Melbourne 16 NDB - ADF selection policy, if any
Melbourne Runway 16 NDB approach chart. Two questions:
It seems that DME is required for this approach. If that is the case should not the title of the approach chart be NDB DME RWY 16?
A chart note states both NDB are required for this approach. I can understand that in that you obviously need BOL for top of descent and ROC for the last check point prior to continuing descent below 1250.
Some argue that the note is meant to convey that after leaving BOL on final the crew must leave one ADF on BOL throughout the final approach and the second ADF (if installed) tuned to ROC. On the other hand if the aircraft is equipped with only one ADF, then clearly after leaving BOL, the single ADF must be re-tuned from BOL to the NDB ahead that is ROC.
Having made that point, why do some maintain that, where two ADF's are installed in an aircraft, then after leaving BOL on descent one ADF should remain on BOL for the approach - rather than tune ROC on both ADF's?
If it is a safe procedure to tune ROC after leaving BOL for an aircraft with single ADF installation (no choice of course) is there a legal or procedural why both ADF's should not be on ROC (after leaving BOL) After all, it could be considered good airmanship to have both on ROC since if one ADF fails the other ADF is already in place as good back-up.