B737 Undifferentiated or Other Model
Flight Crew Last 90 Days 231; Flight Crew Type 393
Situational Awareness; Distraction; Human-Machine Interface
Deviation - Altitude Undershoot; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance
Aircraft; Human Factors; Chart Or Publication
We were flying the MNZNO RNAV SID out of ABQ. The departure has a crossing restriction of Maximum 230 KTS; at or below 9;000 FT at YUGLU and; 8.2 NM later at MNZNO; maximum 250 KTS at 11;500 or above. While leveling off at the 9;000 FT hold down; the aircraft switched from 'VNAV' to 'altitude hold' mode and both the pilot flying and pilot not flying failed to recognize the change. As the pilot flying; I was hand flying the aircraft and was task saturated. I thought we should be climbing but the flight directors were commanding level flight. The Captain had selected 11;500 in the MCP but; due to the mode change; the flight directors were not commanding a climb. About the time we realized the mistake; ATC gave us a heading of 190 and climb to FL200. The ATC clearance came about three miles prior to MNZNO [with us still] at 250 KIAS and 9;000.In retrospect; I would have been better off to utilize the autopilot as opposed to hand flying. The departure is fairly involved with multiple turns and altitude requirements. My normal course of action is to hand fly through 10;000 FT before engaging the autopilot. Had I engaged the autopilot; I believe my situational awareness would have been better and I'd have caught the inadvertent mode change quicker. Additionally; I would submit that these departures are a little different from what we normally see. They're unique in that the altitudes are listed in the verbiage with the route. On most of the commercially provided SIDs; the route is listed at the bottom of the page (in the text portion) and then there is an altitude listed in a separate block. There is no altitude block on the MNZNO and the required altitude is listed in with the text. For standardization purposes the Charts should adopt one method to avoid confusion and potential altitude deviations.
A B737 flight crew failed to comply with the crossing restriction departing ABQ on the MNZNO RNAV SID. Task saturation by the hand flying pilot flying and failure of the pilot not flying to reengage VNAV after complying with restrictions at YUGLU were cited as major contributing factors.