Citation V/Ultra/Encore (C560)
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 45; Flight Crew Total 18000; Flight Crew Type 3000
Communication Breakdown; Confusion
ATC Issue All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance; Flight Crew Became Reoriented
Human Factors; Procedure
Following the ENDEE THREE arrival into MDW; we were given a clearance to Descend Via the ENDEE THREE except maintain 11000. Eleven thousand feet was set into the altitude alerter. Upon switching to Chicago approach control the transition to runway 31C via GAGGA was added to our Descend Via clearance with no mention of 'Except maintain 11000 FT. As we leveled off at 11000 the controller called to inquire if we were going to make the crossing restriction of MOORS at 10000 or below. We advised the controller that we had been previously restricted to 11;000. Descend Via clearances seem to work fine when used as published; however confusion can develop when they are modified. It may seem obvious in retrospect that the 'Except maintain 11000' was omitted from the second clearance; but a busy arrival is no place to be parsing the English language. A phrase such as 'Cancel the 11000 foot restriction' would go a long way to assuring clarity of communication.
After being issued a descend via the ENDEE 3 except maintain 11;000; a CE560 Captain is issued a Runway 31C transition via GAGGA by Approach. Without the altitude being mentioned or modified the Captain levels at 11;000 FT and is queried by ATC as to why.