The captain of an erj-170; following his second TCAS RA in busy terminal areas incident within a wee...

Narrative:

We were at 10;000 ft between esspo intersection and the ord VOR approximately ord 150 deg radial at 10-15 DME and 300 KTS assigned speed when we were given a turn to heading 270 degrees. As captain and pm I had just noticed a couple of TCAS targets when we received a TCAS RA to descend below the 10;000 ft. I confirmed that the first officer PF started to descend via the TCAS resolution as we did not have the target in sight and the TCAS showed the target only 400 ft above our altitude. I then called ord approach to let them know we were descending because of the RA and we were still above 250K. The ord controller responded 'oh yeah; there is a citation at 10;500 ft.' something similar happened to me last week; but without the airspeed issues; going into ewr on a 15 mile final to runway 4R where ATC let some VFR guy go through the 'final' at 500 ft below our altitude without notifying us. These situations are happening way too often anymore in nyc and ord. Why do the controllers have to put traffic with such high speed closure rates i.e. 400-500K with less than 1;000 ft vertical separation?

Original NASA ASRS Text

Title: The Captain of an ERJ-170; following his second TCAS RA in busy terminal areas incident within a week; took vocal exception to ATC permitting 500 foot vertical separation between IFR and VFR traffic in VMC conditions.

Narrative: We were at 10;000 FT between ESSPO intersection and the ORD VOR approximately ORD 150 deg radial at 10-15 DME and 300 KTS assigned speed when we were given a turn to heading 270 degrees. As Captain and PM I had just noticed a couple of TCAS targets when we received a TCAS RA to descend below the 10;000 FT. I confirmed that the F/O PF started to descend via the TCAS resolution as we did not have the target in sight and the TCAS showed the target only 400 FT above our altitude. I then called ORD Approach to let them know we were descending because of the RA and we were still above 250K. The ORD Controller responded 'oh yeah; there is a Citation at 10;500 FT.' Something similar happened to me last week; but without the airspeed issues; going into EWR on a 15 mile final to RWY 4R where ATC let some VFR guy go through the 'Final' at 500 FT below our altitude without notifying us. These situations are happening way too often anymore in NYC and ORD. Why do the controllers have to put traffic with such high speed closure rates i.e. 400-500K with less than 1;000 FT vertical separation?

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.

Attributes
ACN	1121099
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	Descent
Flight Plan	IFR
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Published Material / Policy Deviation - Speed All Types

The captain of an erj-170; following his second TCAS RA in busy terminal areas incident within a week; took vocal exception to ATC permitting 500 foot vertical separation between IFR and VFR traffic in VMC conditions.