Date: 201303
Local time of day: 1801-2400
Location: ABQ.Tower, NM
Aircraft: Regional Jet 700 ER/LR (CRJ700)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Climb
Airspace: Class C ABQ
ATC / advisory: Tower ABQ
Reporter organization: Government
Reporter function: Departure
Human factors: Communication Breakdown; Situational Awareness; Confusion
Anomaly: ATC Issue All Types
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Chart Or Publication; Environment - Non Weather Related; Human Factors; Procedure
Primary problem: Ambiguous

Narrative: [There has been a lot of confusion by flight crews cleared to depart Runway 8 on the MNZNO RNAV SID]. What 'doesn't' work is '...climb via the MNZNO departure (there is always a question about the altitude). What works sometimes is '...climb via the MNZNO departure; maintain FL200.' (This; however; promotes questions from the pilot such as: 'Do we need the speed?' and/or: 'Do we need to stay at 9;000?') Due to that confusion I came up with some phraseology that usually works.What I said this time to this pilot was: '...climb via the MNZNO departure; [except] delete altitude restrictions as long as they are greater [higher] than the [published] restrictions.' The reason I added the last part about the delete altitude restriction was because the MNZNO makes a turn for the high terrain and I wanted to make sure he didn't turn too early. The pilot made the altitude restriction (for the terrain); although he said; 'next time I am going to refuse this clearance; it is dangerous.' I asked him if he thought my clearance was dangerous or the clearance that was issued from Clearance Delivery. He said the one from Clearance Delivery. I told him I appreciated his input.After I worked this aircraft; I had a departure which was an RNAV SID to the north - more confusion and questions on the altitude and even a readback altitude error on the final altitude. So after two for two on confusion and possible errors; I went 'old school' on aircraft number three. 'Old school' entailed issuing a heading and altitude with a later heading to a fix to rejoin the RNAV SID; which worked perfectly!I recommend giving departure headings off runways to maintain 9;000 feet. Let radar climb the aircraft to a safe altitude and clear the aircraft to a fix to join the departure with ZAB. These fixes are great and work well for radar.ABQ has too great a mix of aircraft types and can't compete with the big houses with SIDs.

Callback: The reporter; a veteran Departure Controller; advised that a 'significant' proportion of departures on the MNZNO and a lesser but real proportion of departures on other of the ABQ RNAV SIDs encounter confusion over altitude compliance on these relatively new departures.  She stated that; unless there are arrival conflicts in the vicinity of YUGLO requiring departures to maintain 9;000 feet for spacing she routinely revises departure clearances to a southerly vector and a clearance to FL220 followed; ultimately; by a clearance to a filed fix; on course.A common problem is difficulty for some flights to achieve 'At or above 11;500 feet' at MNZNO which is necessary for required terrain separation.  The analyst noted that the prior required crossing at YUGLO; 'At or below 9;000 feet at MAX 230K;' only 8.2NM from MNZNO; contributes to the difficulty. To comply with the YUGLO restriction most departures will be at reduced thrust and less than optimum climb speed as the transit takes place.  An immediate climb; most likely while at the less than optimum climb speed; would be required by many departures to climb the minimum 2;500 feet prior to MNZNO.  The reporter advised that controllers must closely monitor departures to assure the do; in fact; comply and often must prod flight crews to assure they are aware of the need to expedite their climb.The reporter confirmed the analyst's understanding from previous reports that the airways clearances provided to MNZNO departures include a directive to 'climb and maintain 9;000 feet (a practice she supported based on the need to ensure separation with arrivals).  When asked if she understood the flight crew confusion that could result from a clearance via a SID which includes multiple altitude constraints (at or below 9;000 feet at YUGLO; at or above 11;500 feet at MNZNO and; ultimately; to FL200) when that enroute clearance also includes an ATC directive to 'maintain 9;000 feet' she said she hadn't thought about it but it would explain events where pilots level at 9;000 feet and don't initiate further climb passing YUGLO until alerted by ATC.



Synopsis: Frequent flight crew confusion and resultant altitude deviations when flying the MNZNO RNAV SID from ABQ has convinced the reporter of the need to develop unique phraseology when clearing flights 'via' the procedure. Her suggestions included deleting the 'published' altitude constraints; instead clearing flights to cross all constrained fixes at altitudes 'greater than' the published restrictions. Her preferred method; however; was to give 'old school' heading; altitudes and clearances direct to a fix.