An A320 captain flying the las shead 6 RNAV departure queried ATC about the new waypoints and ATC al...

Narrative:

We departed las runway 25R on the shead 6 RNAV departure. At approximately 4;000 ft MSL; the departure controller cleared us to 'climb to FL190; comply with restrictions.' we selected 19;000 in the altitude window and climb for vertical navigation. After passing roppr (at or below 7;000 ft); I noticed that that the shead 6 had a few new points; and new terminology when compared to the shead 5 departure. I asked the departure controller to clarify the new altitude restrictions; showing both 'at or above' and '(ATC)' at the next several points. (These changes in the depiction and charting terminology were new to me.) the controller replied 'we don't really know why they changed the charts; but it appears that the new altitude restrictions are something for you?' during this discussion; the first officer requested open climb. (This was a typical request on the shead 5; before the new restrictions were added). I then asked the controller to clarify what altitude restrictions he expected us to comply with. He confirmed that we should comply with the altitudes which were depicted as (ATC) altitudes. At this time we were approaching mddog passing 9;000 ft and eventually crossed mddog at approximately 9;500 ft (500 ft high). The remainder of the SID and flight went as published.

Original NASA ASRS Text

Title: An A320 Captain flying the LAS SHEAD 6 RNAV Departure queried ATC about the new waypoints and ATC altitudes shown. ATC did not know the reason for them but they are the altitudes the crew was expected to comply with.

Narrative: We departed LAS Runway 25R on the SHEAD 6 RNAV departure. At approximately 4;000 FT MSL; the Departure Controller cleared us to 'climb to FL190; comply with restrictions.' We selected 19;000 in the altitude window and CLB for vertical navigation. After passing ROPPR (at or below 7;000 FT); I noticed that that the SHEAD 6 had a few new points; and new terminology when compared to the SHEAD 5 departure. I asked the departure controller to clarify the new altitude restrictions; showing both 'at or above' and '(ATC)' at the next several points. (These changes in the depiction and charting terminology were new to me.) The Controller replied 'We don't really know why they changed the charts; but it appears that the new altitude restrictions are something for you?' During this discussion; the First Officer requested open climb. (This was a typical request on the SHEAD 5; before the new restrictions were added). I then asked the Controller to clarify what altitude restrictions he expected us to comply with. He confirmed that we should comply with the altitudes which were depicted as (ATC) altitudes. At this time we were approaching MDDOG passing 9;000 FT and eventually crossed MDDOG at approximately 9;500 FT (500 FT high). The remainder of the SID and flight went as published.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	917479
Time
Date	201011
Local Time Of Day	0001-0600
Place
Locale Reference	LAS.Airport
State Reference	NV
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 240 Flight Crew Total 13000 Flight Crew Type 7000
Events
Anomaly	ATC Issue All Types Deviation - Altitude Crossing Restriction Not Met Deviation - Altitude Overshoot Deviation - Procedural Published Material / Policy

An A320 captain flying the las shead 6 RNAV departure queried ATC about the new waypoints and ATC altitudes shown. ATC did not know the reason for them but they are the altitudes the crew was expected to comply with.