Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 146; Flight Crew Type 146
Confusion; Communication Breakdown
Conflict Airborne Conflict; Deviation - Altitude Overshoot; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Provided Assistance; Flight Crew Took Evasive Action; Flight Crew FLC complied w / Automation / Advisory
Human Factors; Procedure
Our Clearance out of PHX was to depart on the KATMN5 Departure; climb via the SID. The KATMN5 has a top altitude of 8000 feet and a crossing restriction at VANZZ intersection of at or below 8000 feet. Both were briefed and 8000 feet was set in the altitude window. After takeoff we were handed off to PHX Departure. As we began to turn left towards DAVZZ intersection; PHX Departure gave us the revised clearance to 'climb via the SID; except maintain FL210.' We read back the clearance; I asked for VNAV on the automation; then we put FL210 in the altitude box; and I engaged the autopilot.At this point we had a miscommunication about the clearance and I thought PHX Departure wanted us to 'climb and maintain' FL210. Both the Captain and I questioned each other about the clearance; and then removed the restriction of at or below 8000 feet at VANZZ because of a misunderstanding of the climb clearance. We were then given (by PHX Departure) that we had traffic around 2 o'clock. Traffic was in sight and we were climbing around 3000-3500 FPM because we were light. We then received an RA with the traffic; which we complied with; and maintained visual separation. Shortly afterwards; PHX Departure told us that we needed to maintain 8000 feet at VANZZ. We explained that we believed he had given us a clearance to 'climb and maintain' FL210 which removes all restrictions. At that point we realized that we had made a mistake and misinterpreted the 'climb via' clearance.
[Report narrative contained no additional information.]
Air carrier flight crew reported they exceeded an altitude restriction while on the KATMN5 SID.