B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 168
Communication Breakdown; Situational Awareness
ATC Issue All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance
Flight Crew Became Reoriented
Procedure; Human Factors
Our PDC departing out of BWI cleared us fly the TERPZ6 Departure; as well as to 'climb via; except maintain 4000 ft.' After takeoff; upon handoff to Potomac Departure Control; Potomac cleared us to 'climb via the departure.' The aircraft was starting to level at 4000 feet and went into ALT ACQ pitch mode. We quickly consulted the published TERPZ6 Departure and saw that the top altitude was 17;000 feet for our departure transition. We dialed in 17;000 feet in the MCP and re-engaged VNAV. The aircraft was a little slow to re-establish a climb; and we got a query from ATC to verify if we were climbing. We responded in the affirmative. We ended up getting cleared direct for some shortcuts; so there were no problems with complying with any altitude restrictions on the route.Until the newest revision to the TERPZ6; Potomac Departure Controllers were using non-standard phraseology. Up until that point in time; all the Controllers were consistently using the following non-standard phraseology upon check-in with departure: 'Company XXX; Potomac Departure; Climb via departure; except maintain 17;000 feet.' The top altitude was always 17;000 feet; so that last part 'except maintain 17;000 feet' was redundant. I know they were trying to eliminate any ambiguity; but I can bet that most of the Pilots departing from BWI have gotten used to this non-standard phraseology of the extra phrase '...except maintain 17;000 feet' to clarify the climb via clearance. Now this switch from non-standard to standard phraseology - just only 'climb via' is bound to confuse many Pilots; especially those who fly out of BWI often. There is a huge expectation bias to hear the clearance 'climb via; except maintain 17;000 feet.'Make sure the Pilot Flying always briefs the top altitude in the SID; and that we listen carefully and comply with climb via clearances. Re-read the recent published articles on other feedback about climb via clearances.
B737 Captain reported confusion regarding a 'climb via' clearance departing BWI.