Emb-170 first officer experiences a TCAS descend RA approaching ord at 10;000 feet and 300 knots; ca...

Attributes
ACN	1121607
Time
Date	201310
Local Time Of Day	0601-1200
Place
Locale Reference	C90.TRACON
State Reference	IL
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	EMB ERJ 170/175 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Cessna Citation Undifferentiated or Other Model
Person 1
Function	First Officer Pilot Flying
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict Deviation - Altitude Excursion From Assigned Altitude Deviation - Speed All Types

Narrative:

We were at 10;000 feet and assigned 300 knots; between esspo fix and the ord VOR about 10 to 14 DME and given a turn to 270 degrees. The captain saw a few TCAS targets pop up and then we got a RA to descend below 10;000 feet. As we had to descend fast we were not able to slow to 250 knots as we went below 10;000 feet. The target aircraft was very close to us; maybe 200 to 400 feet. The captain called approach to tell them and they and they forgot to tell us there was a citation at 10;500 feet. We had descended below 10;000 feet and were off our altitude and were not able to slow to 250 knots below; due to responding to the RA advisory. That ATC needs to give more warning of aircraft to prevent RA's.

Original NASA ASRS Text

Title: EMB-170 First Officer experiences a TCAS descend RA approaching ORD at 10;000 feet and 300 knots; caused by a Citation at 10;500 feet that ATC forgot to mention.

Narrative: We were at 10;000 feet and assigned 300 knots; between ESSPO fix and the ORD VOR about 10 to 14 DME and given a turn to 270 degrees. The Captain saw a few TCAS targets pop up and then we got a RA to descend below 10;000 feet. As we had to descend fast we were not able to slow to 250 knots as we went below 10;000 feet. The target aircraft was very close to us; maybe 200 to 400 feet. The Captain called Approach to tell them and they and they forgot to tell us there was a Citation at 10;500 feet. We had descended below 10;000 feet and were off our altitude and were not able to slow to 250 knots below; due to responding to the RA Advisory. That ATC needs to give more warning of aircraft to prevent RA's.

Data retrieved from NASA's ASRS site as of July 2013 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.

Emb-170 first officer experiences a TCAS descend RA approaching ord at 10;000 feet and 300 knots; caused by a citation at 10;500 feet that ATC forgot to mention.