A319
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 6.0
Communication Breakdown; Human-Machine Interface; Situational Awareness
Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Returned To Clearance
Airspace Structure; Chart Or Publication; Procedure
I was advised by the Feeder Sector that Aircraft X checked in on the arrival descending to 4000 feet. The controller caught the target altitude upon check in and instructed Aircraft X to maintain 7000 feet instead. I called ARTCC to ask what Aircraft X was issued and they said 'Descend via the arrival; maintain 300 knots.' I had Aircraft X call so I could inquire about the error.  I spoke with the Captain for the flight; about how he interpreted the arrival and why his actions differed from everyone else. He apparently understood the segment altitudes to be the bottom altitude on the arrival that he could rightfully descend to after the mandatory crossing.The assortment of altitudes on the STAR seem unnecessary if the Descend Via only authorizes 110. However; if ZAU cleared the aircraft to Descend Via except cross FYTTE at and maintain 110; it would certainly help clear up any confusion for the occasional confused crew.
C90 Controller reported an ORD arriving aircraft on a STAR issued 'descend via' clearance descended through a crossing restriction on the arrival. The reporter spoke to the pilot who did not understand how to comply with the restrictions on the approach once issued 'descend via' ATC phraseology.