A crj-200 flight crew responded to a TCAS RA with respect to a VFR GA aircraft which intruded on the...

Narrative:

On arrival into abe; was on vector and assigned altitude of 4;000 ft. Had cyan target on TCAS at 1 to 2 o'clock that appeared to be moving toward our flight path. The first officer and I were attempting to visually acquire the traffic when we received an amber TA. I did not have the visual on traffic; but checking the TCAS display he appeared to be in closer than one mile and closing. I told the first officer to prepare to climb. I was about to ask approach about him as we had not been advised of this traffic when the TCAS indicated the target had began to climb and was now indicating less than 400 ft of vertical separation. TCAS RA climb activated and we immediately began climbing. We deviated from our assigned altitude by 2;000 ft climbing to 6;000 before receiving clear of conflict. ATC was advised of the RA and we were cleared to return to our previously assigned altitude. After completing the maneuver and re leveling at 4;000; I asked what the story was on the airplane that had caused it and it was a VFR aircraft that had not maintained his altitude.the threat is separating IFR and VFR traffic by 500 ft in the terminal area. I know it's legal but this is not the first time this has caused me to have an RA. We were flying on an assigned vector and altitude. This one happened pretty quick but I should have been a little quicker to request information on the unknown target and possibly a climb or turn before the RA. In this case there was very little time to take action aside from prompt compliance with the RA.

Original NASA ASRS Text

Title: A CRJ-200 flight crew responded to a TCAS RA with respect to a VFR GA aircraft which intruded on the minimum 500 foot vertical separation requirement climbing toward the CRJ.

Narrative: On arrival into ABE; was on vector and assigned altitude of 4;000 FT. Had cyan target on TCAS at 1 to 2 o'clock that appeared to be moving toward our flight path. The FO and I were attempting to visually acquire the traffic when we received an amber TA. I did not have the visual on traffic; but checking the TCAS display he appeared to be in closer than one mile and closing. I told the First Officer to prepare to climb. I was about to ask Approach about him as we had not been advised of this traffic when the TCAS indicated the target had began to climb and was now indicating less than 400 FT of vertical separation. TCAS RA climb activated and we immediately began climbing. We deviated from our assigned altitude by 2;000 FT climbing to 6;000 before receiving clear of conflict. ATC was advised of the RA and we were cleared to return to our previously assigned altitude. After completing the maneuver and re leveling at 4;000; I asked what the story was on the airplane that had caused it and it was a VFR aircraft that had not maintained his altitude.The threat is separating IFR and VFR traffic by 500 FT in the terminal area. I know it's legal but this is not the first time this has caused me to have an RA. We were flying on an assigned vector and altitude. This one happened pretty quick but I should have been a little quicker to request information on the unknown target and possibly a climb or turn before the RA. In this case there was very little time to take action aside from prompt compliance with the RA.

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.

Attributes
ACN	1155490
Time
Date	201403
Local Time Of Day	0001-0600
Place
Locale Reference	ABE.TRACON
State Reference	PA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Regional Jet 200 ER/LR (CRJ200)
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	Climb
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Pilot Flying First Officer
Events
Anomaly	Conflict Airborne Conflict

A crj-200 flight crew responded to a TCAS RA with respect to a VFR GA aircraft which intruded on the minimum 500 foot vertical separation requirement climbing toward the crj.