Narrative:

Cleared via the shead RNAV departure, we were 3 mi from roppr intersection, at 6300 ft, we were given climb and maintain 8000 ft. Roppr has a 7000 ft crossing restr and ATC did not state 'comply with restrs' nor 'delete restrs.' we leveled at 7000 ft until roppr. After crossing roppr, ATC stated climb and maintain 11000 ft. We started to level at 9000 ft to cross mddog when ATC appeared frustrated and stated I need a fast climb to 11000 ft. We crossed mddog at 10000 ft. (Mddog was a 9000 ft crossing restr.) then the frustrated controller instructed us to climb and maintain FL190 expedite through 15000 ft for traffic. We crossed tarrk at 15000 ft (the RNAV states cross it at 11000 ft). Again, no delete nor comply with restrs. This led to me feeling frustrated and questioning my climb restrs. We have been briefed and briefed that we are to comply with the RNAV requirements unless ATC specifically deletes them. We are caught in the middle. I feel 95% of these departure errors can be eliminated with a phraseology change by ATC. Comply with restrs, then climb and maintain (altitude) or delete restrs, climb and maintain (altitude). This way, the crews won't be second guessing what the controller wants, or they won't be throttling up when ATC says 'climb and maintain,' but miss the part at the end that says: 'comply with restrs.' (that portion should be stated first.) if ATC wants us to disregard the RNAV departure restrs, ATC must specifically state that. Otherwise, confusion will result. Supplemental information from acn 604177: referencing the numerous problems, addressing this specific problem, the potential still exists for altitude busts due to confusing instructions being given just prior to critical leveloff points on the departure. (Many times the autoplt is in the acquire mode and changing the altitude in the window negates the leveloff feature.)

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Original NASA ASRS Text

Title: FLT CREW OF B737-300 EXPRESS GREAT CONCERN REGARDING THE AMBIGUITY OF ALT CLRNCS FROM L30 ON SHEAD RNAV SID OUT OF LAS.

Narrative: CLRED VIA THE SHEAD RNAV DEP, WE WERE 3 MI FROM ROPPR INTXN, AT 6300 FT, WE WERE GIVEN CLB AND MAINTAIN 8000 FT. ROPPR HAS A 7000 FT XING RESTR AND ATC DID NOT STATE 'COMPLY WITH RESTRS' NOR 'DELETE RESTRS.' WE LEVELED AT 7000 FT UNTIL ROPPR. AFTER XING ROPPR, ATC STATED CLB AND MAINTAIN 11000 FT. WE STARTED TO LEVEL AT 9000 FT TO CROSS MDDOG WHEN ATC APPEARED FRUSTRATED AND STATED I NEED A FAST CLB TO 11000 FT. WE CROSSED MDDOG AT 10000 FT. (MDDOG WAS A 9000 FT XING RESTR.) THEN THE FRUSTRATED CTLR INSTRUCTED US TO CLB AND MAINTAIN FL190 EXPEDITE THROUGH 15000 FT FOR TFC. WE CROSSED TARRK AT 15000 FT (THE RNAV STATES CROSS IT AT 11000 FT). AGAIN, NO DELETE NOR COMPLY WITH RESTRS. THIS LED TO ME FEELING FRUSTRATED AND QUESTIONING MY CLB RESTRS. WE HAVE BEEN BRIEFED AND BRIEFED THAT WE ARE TO COMPLY WITH THE RNAV REQUIREMENTS UNLESS ATC SPECIFICALLY DELETES THEM. WE ARE CAUGHT IN THE MIDDLE. I FEEL 95% OF THESE DEP ERRORS CAN BE ELIMINATED WITH A PHRASEOLOGY CHANGE BY ATC. COMPLY WITH RESTRS, THEN CLB AND MAINTAIN (ALT) OR DELETE RESTRS, CLB AND MAINTAIN (ALT). THIS WAY, THE CREWS WON'T BE SECOND GUESSING WHAT THE CTLR WANTS, OR THEY WON'T BE THROTTLING UP WHEN ATC SAYS 'CLB AND MAINTAIN,' BUT MISS THE PART AT THE END THAT SAYS: 'COMPLY WITH RESTRS.' (THAT PORTION SHOULD BE STATED FIRST.) IF ATC WANTS US TO DISREGARD THE RNAV DEP RESTRS, ATC MUST SPECIFICALLY STATE THAT. OTHERWISE, CONFUSION WILL RESULT. SUPPLEMENTAL INFO FROM ACN 604177: REFING THE NUMEROUS PROBS, ADDRESSING THIS SPECIFIC PROB, THE POTENTIAL STILL EXISTS FOR ALT BUSTS DUE TO CONFUSING INSTRUCTIONS BEING GIVEN JUST PRIOR TO CRITICAL LEVELOFF POINTS ON THE DEP. (MANY TIMES THE AUTOPLT IS IN THE ACQUIRE MODE AND CHANGING THE ALT IN THE WINDOW NEGATES THE LEVELOFF FEATURE.)

Data retrieved from NASA's ASRS site as of July 2007 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.