Medium Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
Flight Crew Total 22000
Communication Breakdown; Confusion; Situational Awareness; Workload
ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance
Human Factors; Procedure
We were inbound to DFW on the KLNDR 2 RNAV.  We had been cleared to and had just leveled at FL190 just outside KLNDR. We at this point had not been cleared to descend via the arrival. We heard cleared to descend via KLNDR 2. PF set 15;000 and started to descend. ATC asked if we were level at FL190 as we had not been cleared to descend via the arrival yet. 'You were to expect cleared via the arrival shortly.' At 18;500 we started a climb back to FL190 but ATC told us to descend via KLNDR 2. We continued to descend via the KLNDR 2. Nothing else was said about this confusion by ATC or by us.There was a lot of confusion and freq. congestion between ATC and other aircraft over the new DFW RNAV arrivals that were effective the day before. That contributed to the confusion between our aircraft and ATC over the freq. on being cleared to descend via the arrival. Because of these factors and the quick level off at FL190 and upon hearing cleared to descend via the arrival not expect to be cleared via the arrival is why this event occurred.More CLEAR and CONCISE communications between ATC and PILOTS during these very high workload and complicated RNAV ARRIVALS. Especially when the arrivals have just been changed.
There was a problem with the understanding of the clearance during a very complicated; high workload (descent checks) RNAV STAR.There have been an increasing amount of modifications to these RNAV STAR by ATC because of out bound traffic from DFW and LOVE when approaching the terminal area from the NE and SE. Also with most of these STAR's being developed for NEXT GEN aircraft it has highly complicated and increased our workload in older aircraft; During phase of flight we should be focused on managing the aircraft; and often times find ourselves heads down trying to fly the STAR.
Air carrier flight crew reported they thought they were cleared to descend on the DFW KLNDR 2 Arrival; but ATC said that it was an 'expect' clearance.