Air carrier crew receives confusing clearance for approach at ord, il.

Attributes
ACN	467670
Time
Date	200003
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ord.airport
State Reference	IL
Altitude	msl single value : 5000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : c90.tracon tower : ord.tower
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 27l
Flight Phase	descent : approach
Route In Use	approach : visual approach : instrument precision arrival : on vectors
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : c90.tracon
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	467670
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : commercial pilot : instrument

Narrative:

On downwind for the approach to ord runway 27L, we were assigned a vector to join the string of traffic for runway 27R. We were told to follow an aircraft that entered the line of traffic ahead of us. Approach directed that upon visual with aircraft Y 'follow him.' while turning to intercept the runway 27R localizer, we were advised by approach control that aircraft Y was going to the 'parallel.' the next call to us was 'cleared for the visual, contact tower at willt' which was the fix for runway 27L. Confusion then existed between me and the first officer as to which runway we were now cleared to continue an approach to. I called approach to clarify and he directed an immediate turn to the left to join runway 27L extended centerline and repeated call to contact tower at willt. With the controller's use of aircraft Y going to the parallel, it was unclr whether we should then continue to follow him or not. A potential for a traffic conflict could have resulted during the confusion.

Original NASA ASRS Text

Title: ACR CREW RECEIVES CONFUSING CLRNC FOR APCH AT ORD, IL.

Narrative: ON DOWNWIND FOR THE APCH TO ORD RWY 27L, WE WERE ASSIGNED A VECTOR TO JOIN THE STRING OF TFC FOR RWY 27R. WE WERE TOLD TO FOLLOW AN ACFT THAT ENTERED THE LINE OF TFC AHEAD OF US. APCH DIRECTED THAT UPON VISUAL WITH ACFT Y 'FOLLOW HIM.' WHILE TURNING TO INTERCEPT THE RWY 27R LOC, WE WERE ADVISED BY APCH CTL THAT ACFT Y WAS GOING TO THE 'PARALLEL.' THE NEXT CALL TO US WAS 'CLRED FOR THE VISUAL, CONTACT TWR AT WILLT' WHICH WAS THE FIX FOR RWY 27L. CONFUSION THEN EXISTED BTWN ME AND THE FO AS TO WHICH RWY WE WERE NOW CLRED TO CONTINUE AN APCH TO. I CALLED APCH TO CLARIFY AND HE DIRECTED AN IMMEDIATE TURN TO THE L TO JOIN RWY 27L EXTENDED CTRLINE AND REPEATED CALL TO CONTACT TWR AT WILLT. WITH THE CTLR'S USE OF ACFT Y GOING TO THE PARALLEL, IT WAS UNCLR WHETHER WE SHOULD THEN CONTINUE TO FOLLOW HIM OR NOT. A POTENTIAL FOR A TFC CONFLICT COULD HAVE RESULTED DURING THE CONFUSION.

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.