Narrative:

Ord approach controller and ord tower controller sequenced us too close to another landing aircraft. On final, at about 2 mi separation, I queried the tower controller 'how does spacing look for us?' he replied 'it looks tight.' I already had in mind that we would be going around. Shortly after, we received the go around clearance. The controller said 'turn right to a heading of one-four-zero, climb and maintain one-four-thousand.' the altitude seemed high to me, so I read back, very distinctly, 'climb to one-four thousand' placing special emphasis on the 'one-four-thousand.' my captain later said he had distinctly heard me. The controller did not correct my readback. After switching to another approach controller for sequencing back to ord, as we were passing 6000 ft, I noticed TCASII traffic 2000 ft higher than us. Then I looked out and saw the B727 cruising at 8000 ft and crossing our path from left to right. The controller asked us if we were given 4000 ft. We said 'no, 14000 ft.' the controller said 'no problem, just level at 6000 for traffic.' we got a TA at around 6400 ft (no RA) and started our descent back to 6000 ft. I believe the problem may have been workload for the controllers. It was a busy time (average, not unusually heavy for ord). The original approach controller kept us high too long and forgot to clear us for the ILS approach. After he did, we were told to keep our speed up. I had been monitoring the spacing between us and the aircraft in front of us on final. Spacing looked too close to me. When I switched to tower, he cleared us to land, making no mention of the airplane in front of us. I truly thought at the time he didn't know where we were, perhaps confusing our location with another airplane. When I could get a word in, and knowing it was already the controller about the spacing. His reply was the first indication he gave us that he thought there would be a problem. I think it may have been his first realization there was a problem with spacing. When he gave us the go around instructions, he seemed flustered. I believe the mistake was incorrectly saying 'one-four-thousand' immediately after saying 'one-four-zero.'

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Original NASA ASRS Text

Title: ACR SPACE TOO CLOSE EXECUTES A MISSED APCH, CONFUSES CLRED ALT AND HAS RESULTING TFC CONFLICT.

Narrative: ORD APCH CTLR AND ORD TWR CTLR SEQUENCED US TOO CLOSE TO ANOTHER LNDG ACFT. ON FINAL, AT ABOUT 2 MI SEPARATION, I QUERIED THE TWR CTLR 'HOW DOES SPACING LOOK FOR US?' HE REPLIED 'IT LOOKS TIGHT.' I ALREADY HAD IN MIND THAT WE WOULD BE GOING AROUND. SHORTLY AFTER, WE RECEIVED THE GAR CLRNC. THE CTLR SAID 'TURN R TO A HDG OF ONE-FOUR-ZERO, CLB AND MAINTAIN ONE-FOUR-THOUSAND.' THE ALT SEEMED HIGH TO ME, SO I READ BACK, VERY DISTINCTLY, 'CLB TO ONE-FOUR THOUSAND' PLACING SPECIAL EMPHASIS ON THE 'ONE-FOUR-THOUSAND.' MY CAPT LATER SAID HE HAD DISTINCTLY HEARD ME. THE CTLR DID NOT CORRECT MY READBACK. AFTER SWITCHING TO ANOTHER APCH CTLR FOR SEQUENCING BACK TO ORD, AS WE WERE PASSING 6000 FT, I NOTICED TCASII TFC 2000 FT HIGHER THAN US. THEN I LOOKED OUT AND SAW THE B727 CRUISING AT 8000 FT AND XING OUR PATH FROM L TO R. THE CTLR ASKED US IF WE WERE GIVEN 4000 FT. WE SAID 'NO, 14000 FT.' THE CTLR SAID 'NO PROB, JUST LEVEL AT 6000 FOR TFC.' WE GOT A TA AT AROUND 6400 FT (NO RA) AND STARTED OUR DSCNT BACK TO 6000 FT. I BELIEVE THE PROB MAY HAVE BEEN WORKLOAD FOR THE CTLRS. IT WAS A BUSY TIME (AVERAGE, NOT UNUSUALLY HVY FOR ORD). THE ORIGINAL APCH CTLR KEPT US HIGH TOO LONG AND FORGOT TO CLR US FOR THE ILS APCH. AFTER HE DID, WE WERE TOLD TO KEEP OUR SPD UP. I HAD BEEN MONITORING THE SPACING BTWN US AND THE ACFT IN FRONT OF US ON FINAL. SPACING LOOKED TOO CLOSE TO ME. WHEN I SWITCHED TO TWR, HE CLRED US TO LAND, MAKING NO MENTION OF THE AIRPLANE IN FRONT OF US. I TRULY THOUGHT AT THE TIME HE DIDN'T KNOW WHERE WE WERE, PERHAPS CONFUSING OUR LOCATION WITH ANOTHER AIRPLANE. WHEN I COULD GET A WORD IN, AND KNOWING IT WAS ALREADY THE CTLR ABOUT THE SPACING. HIS REPLY WAS THE FIRST INDICATION HE GAVE US THAT HE THOUGHT THERE WOULD BE A PROB. I THINK IT MAY HAVE BEEN HIS FIRST REALIZATION THERE WAS A PROB WITH SPACING. WHEN HE GAVE US THE GAR INSTRUCTIONS, HE SEEMED FLUSTERED. I BELIEVE THE MISTAKE WAS INCORRECTLY SAYING 'ONE-FOUR-THOUSAND' IMMEDIATELY AFTER SAYING 'ONE-FOUR-ZERO.'

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.