Widebody; Low Wing; 4 Turbojet Eng
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 7.0
Human-Machine Interface; Situational Awareness
ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Air Traffic Control Separated Traffic
Human Factors; Chart Or Publication; Airspace Structure; Procedure
Aircraft X on the HYPER7 Arrival; deviated after the LITEY intersection. The crossing restriction at LITEY is 'Maintain 40'. After LITEY; Aircraft X started to descend to 037 to reach DADEY at or above 30. Seeing that Aircraft X had busted his altitude; I instructed him to slow and maintain 30. Meanwhile; Aircraft Y on the CAVLR Arrival from the south was being vectored to hit the gap between Aircraft X and the previous arrival. At XA:31:51Z; Aircraft Y was instructed; 'Turn left heading 280; maintain 20'. Aircraft Y read back 'Left 270; down to 20'. Read back of heading by the pilot was not correct; but it wasn't going to effect the sequence so I let it slide. Twenty-four seconds later and roughly 1 mile; I asked the pilot; 'Are you in the turn?' The reason I asked the pilot if he was in the turn is because the IAD Radar Sensor is currently OTS. In FUSION radar; there can be a delay; at low level; within 10-12 miles of the field. Sometimes the aircraft doesn't appear to be in the turn and then there will be a sudden 'leap' as FUSION figures out what heading the aircraft it traveling. In this case; the pilot acknowledged that he was 'late on the turn' and he still had not started his descent to 2000 feet. I had purposely not cleared Aircraft X for an approach so that I could maintain altitude separation until I was turned toward the airfield and cleared for the visual approach with Aircraft Y. Once I realized I would not have the needed separation; on final; between Aircraft Y and Aircraft X. I vectored Aircraft X off the localizer for re-sequence and to reestablish separation. Aircraft X deviating on the HYPER7 Arrival is what started this sequence of events. We have a known problem with foreign air carriers busting their altitudes after being issued a 'descend via clearance'. I am told our current RNAV arrivals do not meet current PBN [Performance Based Navigation] standards. Our redesigned procedures for IAD trips do meet standards for PBN arrivals. Those new procedures are 99% complete and awaiting finalization with an implementation date of 'some time in Jan 2020'. If we do not fix our arrivals immediately; there is a real and immediate possibility of a mid-air in the vicinity of FDK airport. LITEY (4000ft) over lies FDK airport and departures off FDK climb to 3000 feet. Aircraft missing their altitudes at LITEY (4000ft) or COVUR (7000ft) have a very high chance of hitting a FDK departure or an aircraft crossing V214 at 6000 feet. I will be doing another report tomorrow illustrating the near miss with an aircraft missing COVUR at 7000 ft and cutting off another aircraft on V214 at 6000ft. Again; with our current arrival design; a severe loss has already occurred and more deviations are happening every day.
PCT TRACON Controller reported one aircraft did not comply with a crossing restriction and another aircraft did not comply with a heading or altitude assignment causing them to have to vector one off final to maintain separation.