Light Transport; Low Wing; 2 Turbojet Eng
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 11
Communication Breakdown
ATC Issue All Types; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Returned To Clearance
Procedure; Human Factors
I was training a Radar Developmental on Sector 13 (the northwest arrival gate) during the morning rush into DEN. Aircraft X checked on our frequency (with no speed assigned) and was told to descend via the MOLTN2 arrival.  Aircraft X read back; 'Descend via the MOLTN2.'  Later Aircraft X asked; 'Do you want us to go fast or comply with the speeds?'  The Radar Controller told Aircraft X to comply with the speeds beginning at RAMMS.  Aircraft X read back; 'Rodger; comply at RAMMS.'  Aircraft X was later shipped to DEN Approach.  Moments later DEN Approach called and talked with our D-side Controller and questioned the speed restrictions we were giving.  They told her that Aircraft X came over saying they were told to go as fast as they can and comply with speeds after RAMMS.  When our D-side told us what had transpired with we informed her that it would be a pilot deviation. The D-side called back to DEN Approach and told them we were going to file a pilot deviation.  Our Supervisor was notified and we reviewed the transmissions with the OMIC.  We told them a pilot deviation needed to be filed.  It was not clear if DEN Approach read the pilot the Possible Pilot Deviation Statement.We have had so many problems with the northwest arrival gate at DEN.  Approach usually assumes we did something wrong.  I believe we are not filing enough pilot deviations when things occur between facilities at the gate.  Our Center needs to be more aggressive in filing and not leaving it up to DEN Approach or assuming they did it.
Aircraft X had checked on and was given 'Descend via the MOLTN2 Arrival.' Aircraft X read the clearance back.  A short time after that Aircraft X said he was given a fast speed and asked if he needed to comply with the speeds along the MOLTN2 arrival.  In response I told him; 'Comply with the speeds beginning at RAMMS;' (RAMMS speed restriction is 250 knots) and Aircraft X read back that they will comply beginning at RAMMS.  After giving Aircraft X the frequency change to Denver TRACON; Denver TRACON calls to the Radar Associate saying the Aircraft X was given fast until RAMMS then slow down for the arrival. Training on the pilots' side that ATC does expect them to comply with the restrictions along arrivals or the restrictions issued by controllers.
ZDV Instructor and Developmental report of a pilot who asks if they need to comply with the restrictions for speed on a STAR and the Developmental advises the pilot after a certain point they need to comply.  The pilot later on gets written up for violating the speeds on the STAR.