A330
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Conflict NMAC; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance
Flight Crew Took Evasive Action
Airspace Structure; Human Factors
At around 4500 ft descending on the HYPER7 STAR to 19L waypoint YYANG passed inbound DADEY; cleared to descend according the STAR; cleared to intercept the LOC 19L; we received a TCAS TA. Even coming directly out of the sun the intruder was quickly identified about 300 ft lower approaching fast from a 1 to 2 a clock position directly towards us. The PF reacted instantly and followed the upcoming TCAS RA. Even with this quick reaction the intruder; a PA42 twin turboprop; passed just 100 feet (-01red) below our cockpit. ATC was very busy and our TCAS RA call could only be sent with some delay. Our information; TCAS RA; nearmiss; twin turboprop 100ft lower; was not commented by ATC but we were cleared to descend to 3000 feet for the ILS 19L. We landed without further disturbances.
[Report narrative contained no additional information.]
A330 flight crew reported a TCAS RA and NMAC with a PA42 on the HYPER7 STAR to IAD.