B777 Undifferentiated or Other Model
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Flight Crew Last 90 Days 179; Flight Crew Total 13106; Flight Crew Type 1635
Confusion; Communication Breakdown
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Procedure
Have a procedural complaint about new arrival into SFO. The PIRAT2 RNAV arrival is new and for a while was not being used by ATC. Old arrival procedure was direct PIRAT - cross PIRAT at 10;000 [feet]. New procedure has numerous step down fixes; altitudes; and speeds. Today we were filed PIRAT2 and when we got in radar contact with Oakland; were given direct PIRAT; cross at 10;000 [feet]. RNAV procedure says PIRAT 15;000 [feet] or below. Fix prior to PIRAT has speed at 260 kts.; so we asked 'Do you need a speed at PIRAT?'; ATC says no. So now I'm wondering are we on the arrival or not. ATC never said descend via; or cancel PIRAT2. From PIRAT on; there are two more fixes/speeds. Do we need to follow the path or not? Now a frequency change and a very busy controller; who say expect vectors for ILS. I was confused as what we should doing. All worked out; but this has happened to me before; and ATC needs to get verbiage correct; i.e. 'cleared to descend via PIRAT2; except cross PIRAT at 10;000 [feet]' or something else. I know the fix is to just ask; but sometimes you don't have time to go into a whole dissertation as to what ATC expects.
B777 Captain reported unclear instructions from ATC.