Medium Large Transport
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 248
Situational Awareness; Communication Breakdown; Confusion; Distraction
ATC Issue All Types; Conflict Airborne Conflict; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance; Flight Crew Took Evasive Action
Procedure; Human Factors
During climb on EXTAN4 SID; Crew was leveling off at assigned altitude of 10;000 feet while proceeding direct to KIDNG intersection. ATC stated 'climb via SID.' Unsure of ATC clearance request; PF asked PM to clarify altitude. ATC replied climb to FL230. Crew complied and continued to climb to FL230. At 10;500 MSL the Controller notified the Crew another aircraft was descending to 12;000 feet directly above. The PF realized this conflict and immediately arrested the climb topping out at 11;400 MSL and began a shallow descent back down to 10;000 MSL. A TCAS RA occurred but the shallow descent already met the TCAS RA requirement with clear of conflict occurring in two seconds. Descending aircraft passed behind and 2000 feet above as viewed on TCAS display.The flight was given direct to EXTAN on the departure and to continue to climb to FL230. Crew was asked to call ATC by phone. Flight continued to destination as filed. During phonecon with ATC; ATC stated they meant the FLT to stay at 10;000 MSL until meeting the at or below 10;000 MSL restriction at KIDNG intersection; climb to FL230. ATC also stated this confusion occurs multiple (said hundreds of) times daily.
We were cleared 'climb via the SID; except maintain 10;000 feet' in the PDC. We departed 34L in DEN and were given direct KIDNG (at below 10;000 feet at KIDNG). The Captain called for VNAV and I selected VNAV and stated VNAV PATH. Approximately five miles from KIDNG; ATC told us to 'climb via the SID'. The Captain asked me to query the Controller as to whether or not he wanted us to climb to FL230; as we had begun to level off at 10;000 feet. The Controller replied; 'maintain 230;' to the best of my recollection. We began our climb and were alerted by ATC of traffic 2000 feet above. About that time; at about 11;000 feet; we received an RA and the Captain descended. We both understood to climb to FL230; but we were both in the red as to why VNAV allowed us to climb above 10;000 feet; and also whether or not we misunderstood the clearance. ATC told us to call a number for possible Pilot Deviation.
Air carrier flight crew reported they misunderstood ATC's 'climb via' instruction while on the EXTAN4 RNAV Departure.  The flight crew flew through the 10;000 FT crossing restriction at KIDNG intersection; and took evasive action to resolve a conflict RA.