MD80 crew and a learjet had less than legal separation in ZAU class a.

Attributes
ACN	596223
Time
Date	200310
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : gij.vortac
State Reference	MI
Altitude	msl single value : 20500
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Flight Phase	climbout : vacating altitude climbout : intermediate altitude
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zau.artcc
Make Model Name	Gates Learjet Corp Undifferentiated or Other Model
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	596223
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	conflict : airborne critical non adherence : published procedure non adherence : required legal separation non adherence : far
Independent Detector	aircraft equipment : tcas other flight crewa other flight crewb
Resolutory Action	flight crew : took evasive action other
Consequence	faa : investigated other
Miss Distance	horizontal : 6000 vertical : 400
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Ambiguous

Narrative:

Near miss. Responded to an RA climbing through FL205. RA issued was climb, then immediately followed by 'climb, climb now.' TCASII commanded a 2000 FPM climb which was followed. It was necessary for the situation, but did not conflict with ATC's instructions as we were in a climb to FL230. No clearance deviation resulted, no injuries. The vertical distance was 400 ft, under the aircraft's nose. The aircraft was a learjet. Dispatch was contacted and given the information they requested. ZAU, manager on duty, was contacted and given the information they requested. A pilot event questionnaire was filled out. For controled airspace this was near fatal and totally unacceptable. Additional information. In climb out going through FL205, obtained TCASII TA immediately followed by RA to climb, then climb, climb now. Autoplt disconnected and followed TCASII climb command of 2000 FPM passing to right of our aircraft. TCASII indicated aircraft learjet passed 400 ft below with less than 1 mi horizontal separation. The RA was followed, it was necessary for the situation, it did not conflict with ATC instructions nor did it result in a clearance deviation. ATC was advised of the RA and was told we would be filing a near miss report. The report was filled with ZAU. Shortly after the incident, dispatch was notified of the near miss and the requested information was exchanged.

Original NASA ASRS Text

Title: MD80 CREW AND A LEARJET HAD LESS THAN LEGAL SEPARATION IN ZAU CLASS A.

Narrative: NEAR MISS. RESPONDED TO AN RA CLBING THROUGH FL205. RA ISSUED WAS CLB, THEN IMMEDIATELY FOLLOWED BY 'CLB, CLB NOW.' TCASII COMMANDED A 2000 FPM CLB WHICH WAS FOLLOWED. IT WAS NECESSARY FOR THE SIT, BUT DID NOT CONFLICT WITH ATC'S INSTRUCTIONS AS WE WERE IN A CLB TO FL230. NO CLRNC DEV RESULTED, NO INJURIES. THE VERT DISTANCE WAS 400 FT, UNDER THE ACFT'S NOSE. THE ACFT WAS A LEARJET. DISPATCH WAS CONTACTED AND GIVEN THE INFO THEY REQUESTED. ZAU, MGR ON DUTY, WAS CONTACTED AND GIVEN THE INFO THEY REQUESTED. A PLT EVENT QUESTIONNAIRE WAS FILLED OUT. FOR CTLED AIRSPACE THIS WAS NEAR FATAL AND TOTALLY UNACCEPTABLE. ADDITIONAL INFO. IN CLBOUT GOING THROUGH FL205, OBTAINED TCASII TA IMMEDIATELY FOLLOWED BY RA TO CLB, THEN CLB, CLB NOW. AUTOPLT DISCONNECTED AND FOLLOWED TCASII CLB COMMAND OF 2000 FPM PASSING TO R OF OUR ACFT. TCASII INDICATED ACFT LEARJET PASSED 400 FT BELOW WITH LESS THAN 1 MI HORIZ SEPARATION. THE RA WAS FOLLOWED, IT WAS NECESSARY FOR THE SIT, IT DID NOT CONFLICT WITH ATC INSTRUCTIONS NOR DID IT RESULT IN A CLRNC DEV. ATC WAS ADVISED OF THE RA AND WAS TOLD WE WOULD BE FILING A NEAR MISS RPT. THE RPT WAS FILLED WITH ZAU. SHORTLY AFTER THE INCIDENT, DISPATCH WAS NOTIFIED OF THE NEAR MISS AND THE REQUESTED INFO WAS EXCHANGED.

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.