MD80 crew got a TCASII RA.

Attributes
ACN	413780
Time
Date	199809
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : obk airport : ord
State Reference	IL
Altitude	msl bound lower : 7750 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ord
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	descent other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	other : unknown
Flight Phase	cruise other
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
ASRS Report	413780
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	413779
Events
Anomaly	altitude deviation : overshoot conflict : airborne less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action other
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

Responded to an RA while on arrival to ord. We were to level at 8000 ft. Lowest altitude was 7750 ft. After clear of conflict, returned to 8000 ft. Supplemental information from acn 413779: in descent about to level 8000 ft, had offending VFR traffic visually at 7500 ft. Received a monitor vertical speed command when vertical velocity indicator was not in the green. This persuaded the first officer to fly through 8000 ft momentarily in an effort to comply.

Original NASA ASRS Text

Title: MD80 CREW GOT A TCASII RA.

Narrative: RESPONDED TO AN RA WHILE ON ARR TO ORD. WE WERE TO LEVEL AT 8000 FT. LOWEST ALT WAS 7750 FT. AFTER CLR OF CONFLICT, RETURNED TO 8000 FT. SUPPLEMENTAL INFO FROM ACN 413779: IN DSCNT ABOUT TO LEVEL 8000 FT, HAD OFFENDING VFR TFC VISUALLY AT 7500 FT. RECEIVED A MONITOR VERT SPD COMMAND WHEN VERT VELOCITY INDICATOR WAS NOT IN THE GREEN. THIS PERSUADED THE FO TO FLY THROUGH 8000 FT MOMENTARILY IN AN EFFORT TO COMPLY.

Data retrieved from NASA's ASRS site as of July 2007 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.