An A320 Flight Crew was distracted by an ECAM message that was the predictable result of an MEL procedure. Altitude and airspeed deviations and a TCAS RA resulted.
Synopsis
An A320 Flight Crew was distracted by an ECAM message that was the predictable result of an MEL procedure. Altitude and airspeed deviations and a TCAS RA resulted.
Narrative
Prior to departing LAS on runway 25R; FMGC was cross checked for proper runway and departure loaded; and cross checked for accuracy. The aircraft had an MEL applied which contained a confusing and vague written operations procedure; that was discussed at length prior to departure. The MEL also had a maintenance action applied which consisted of pulling and collaring two circuit breakers. Due to heavy weight and mountainous terrain; the Crew elected to use TOGA thrust for takeoff. Approaching thrust reduction altitude after takeoff; the Crew received an ECAM alert stating 'CB Tripped Rear PNL S-V'. This distracted the Crew for a few moments; until we realized the message was due to the maintenance action applied in connection with the MEL; since one of the collared circuit breakers was an ECAM monitored breaker. This momentary distraction caused a delay in reducing the thrust setting until after passing RBELL intersection on the departure; on the runway heading; causing concern and an instant attempt to initiate a turn in heading mode. The aircraft initially started a turn in the opposite direction; so the autopilot was disconnected and the turn was initiated manually. Both pilots realized thrust was still in TOGA and the speed was increasing; along with the concern for the 'at or below 7000' restriction at intersection ROPPR. While now hand flying with auto thrust disengaged; turning to intercept the correct departure path and nearing an altitude restriction; we were quite busy. At this time ATC called to notify us of being off lateral path and wanted to know if we were having difficulty. As we were arresting the climb rate to comply with the departure restrictions; we exceeded the 7000 foot limit by approximately 200 feet; causing a concerted effort to descend; which again caused and overshoot of approximately 200 feet; setting off the altitude alerter in the cockpit; adding to the confusion. About this time; a TCAS RA was received requiring an immediate climb which was accomplished. We advised ATC of the TCAS alert and they instructed us to proceed direct to HITME intersection and climb to FL190. We then began to build back the automation by engaging auto thrust; autopilot and flight directors and inserting direct HITME. The flight proceeded uneventfully to the destination.
Second reporter narrative
Factors that contributed to the event were: Confusion over ambiguity of MEL operations procedure; and lack of clarity associated with inoperative equipment. A complicated departure procedure including an 'at or below' altitude restriction; coupled with a special engine failure on takeoff procedure which initiates a turn in a direction opposite to the SID. Distraction and confusion caused by ATC requesting information and then changing departure clearance in the middle of this event. Added distraction of aural altitude alert sounding and lastly the added complication of a TCAS RA alert and associated maneuver.If an MEL requires a circuit breaker to be pulled and collared and the breaker is a 'monitored' breaker; the MEL operations procedure should remind pilots that an ECAM alert will be presented once the aircraft departs the FWS (Fault Warning System) inhibit phase of takeoff. In addition; special engine failure on takeoff pages should not contain a maneuver which is completely opposite the normal and standard departure routing (ie. right turn at LAS 2.1 DME if engine fails; or left turn at REBLL for normal departure.)
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.