Date: 201909
Local time of day: 0601-1200
Location: ZZZ.VOR, US
Flight conditions: VMC
Light: Daylight
Aircraft: Citation X (C750)
Operator: Fractional
Operating under: Part 135
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Reporter organization: Fractional
Reporter function: Pilot Not Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Human factors: Communication Breakdown; Situational Awareness; Confusion
Anomaly: ATC Issue All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance
Detector: Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: About 110 northwest of ZZZ; Center Controller asked us to descend to FL360. I asked if pilot discretion ok. Controller said descend now to FL390; then pilot discretion to FL360. PF (Pilot Flying) started to descend; and Controller asked us to descend through FL400 within 4 minutes. I acknowledged that request; and PF set up a descent which would have us through FL400 in about 3 minutes. After 1.5 minutes; Controller requested us again to be through FL400 in 2 minutes. I replied; 'No problem.' Then he requested us to cross 90 miles west of ZZZ at FL300. As I was entering the restriction in the FMC (Flight Management Computer) the Controller said turn left 20 degrees for spacing; and then asked us if there was a problem. I did not realize that he was referring to the 90 mile crossing restriction. I thought he was still talking about the requirement to be at FL400 within the original 4 minute limit; and we were through FL400 and leveling at FL390; so I responded with; 'No problem.' He then asked if we could still make the restriction of 90 west of ZZZ. I told him I did not know as we were on a heading of 20 degrees left. He then cleared us direct ZZZ. We were now approximately 93 miles west of ZZZ at FL390; so I told him that now that we were direct and only a couple of miles from ZZZ; that we could not make the restriction. He then said; 'That's why I asked you if there was a problem.' We had thought when he asked us that question he was still talking about if we could make the FL400 restriction in 4 minutes. He then said to descend to FL300 now; and told us that he was referring to the FL300 altitude as he had conflicting traffic. I told him I was sorry for the misunderstanding and confusion and that we were now level at FL300.A misunderstanding between the Controller and the two pilots; of the altitude requirements due to the Controller turning us to a heading on descent; which then removes the crossing restriction. Then clearing us direct to ZZZ and requiring us to meet that same restriction when we were too close to possibly make the restriction. As well as a total misunderstanding between the Controller and the pilots of which part of the descent restrictions he was referring to when he asked us if there was a problem. Controller more clearly defining what he was referring to when he asked us if there was a problem. Pilots ensuring what the Controller was referring to when he asked if there was a problem.




Synopsis: CE750 pilot reported misunderstanding ATC instructions and missing altitude requirements.