B737 first officer reported taking evasive action on arrival into pdx in response to an RA that was ...

Attributes
ACN	1442775
Time
Date	201704
Local Time Of Day	1201-1800
Place
Locale Reference	PDX.Airport
State Reference	OR
Environment
Light	Daylight
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Aerobatic
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Person 1
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 160 Flight Crew Type 4500
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict

Narrative:

While on right downwind for runway 10R 10 miles west of pdx ATC reported traffic ahead climbing and descending. The controller stated that he had lost radar contact on the aircraft. While searching for traffic we saw what looked like a strange cloud on a clear day. It turned out to be smoke from a dark colored aerobatic aircraft doing vertical maneuvers. The aircraft came very close to us and we received a climb RA. The captain complied with the RA and turned to the left to avoid collision. We left our assigned altitude of 4000 and climbed to about 4400 ft. We turned the aircraft 20 to 45 degrees to the south off our assigned heading. ATC apologized on frequency and we landed 10R.there is a serious safety threat having IFR aircraft vectored in that area if aerobatic aircraft will be practicing there. In the future I will be more proactive and ask for a turn away from unknown aircraft.

Original NASA ASRS Text

Title: B737 First Officer reported taking evasive action on arrival into PDX in response to an RA that was triggered by an aerobatic aircraft maneuvering near them.

Narrative: While on right downwind for Runway 10R 10 miles west of PDX ATC reported traffic ahead climbing and descending. The Controller stated that he had lost radar contact on the aircraft. While searching for traffic we saw what looked like a strange cloud on a clear day. It turned out to be smoke from a dark colored aerobatic aircraft doing vertical maneuvers. The aircraft came very close to us and we received a climb RA. The Captain complied with the RA and turned to the left to avoid collision. We left our assigned altitude of 4000 and climbed to about 4400 ft. We turned the aircraft 20 to 45 degrees to the south off our assigned heading. ATC apologized on frequency and we landed 10R.There is a serious safety threat having IFR aircraft vectored in that area if aerobatic aircraft will be practicing there. In the future I will be more proactive and ask for a turn away from unknown aircraft.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

B737 first officer reported taking evasive action on arrival into pdx in response to an RA that was triggered by an aerobatic aircraft maneuvering near them.