Narrative:

First officer received clearance from dtw clearance delivery prior to start. During normal checklist procedures, the clearance was reviewed by captain and first officer, including reference to altitude of 12000 ft. Captain asked first officer if 12000 ft was correct as per clearance delivery. He replied that is what he heard, wrote down and read back to clearance delivery. Normal pushback, start engine and taxi procedures were then followed. Captain was PF. Takeoff was normal. Tower had issued a heading of 195 degrees after takeoff (takeoff runway 21C). Takeoff was behind an airbus 320. Wake turbulence was encountered at approximately 500 ft AGL. Captain was hand flying at this time and concentrated on aircraft control. Tower asked us to contact departure control. Captain noticed first officer was experiencing difficulty in contacting departure control. Contact with departure control was made and departure control replied radar contact 10 mi southwest of dtw. Another turn was issued by departure control. No further wake turbulence was experienced and autoplt was then engaged. Then at approximately 10500 ft, departure control advised us to maintain 10000 ft. First officer replied back we were already above 10000 ft. Captain stopped climb, disengaged autoplt and started descent to 10000 ft. TCASII advised descend, after the descent had already been initiated. When we leveled at 10000 ft, RA stopped. First officer stated that he had checked in with departure control stating 'out of 6400 ft for 12000 ft.' apparently no correction of an erroneous altitude was caught by either clearance delivery or departure control. The crew had no reason to suspect anything was wrong and not to fly to the altitude of 12000 ft. The human error in this situation is the difficulty in the 10000 ft, 11000 ft, and 12000 ft readbacks to clearance delivery. Also, departure control not catching the 12000 ft altitude readback. Sometimes things are heard so often and repeatedly, that you might hear what you expect to hear regardless of what is really said. Unfortunately, flcs are often prone not to question clrncs given to them by ATC. Callback conversation with reporter revealed the following information: reporter states that the wake turbulence incident was not dramatic but his attention focused on assuring control of the aircraft in case the wake turbulence became worse. This kind of wake turbulence experience is not abnormal in a busy departure environment. It was brief and he maintained aircraft control. The altitude problem was a complete confusion communication issue.

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Original NASA ASRS Text

Title: AVRO RJ85 ENCOUNTERS WAKE TURB ON CLBOUT THEN HAS CONFUSION REGARDING ASSIGNED ALT AND RECEIVES A TCASII RA.

Narrative: FO RECEIVED CLRNC FROM DTW CLRNC DELIVERY PRIOR TO START. DURING NORMAL CHKLIST PROCS, THE CLRNC WAS REVIEWED BY CAPT AND FO, INCLUDING REF TO ALT OF 12000 FT. CAPT ASKED FO IF 12000 FT WAS CORRECT AS PER CLRNC DELIVERY. HE REPLIED THAT IS WHAT HE HEARD, WROTE DOWN AND READ BACK TO CLRNC DELIVERY. NORMAL PUSHBACK, START ENG AND TAXI PROCS WERE THEN FOLLOWED. CAPT WAS PF. TKOF WAS NORMAL. TWR HAD ISSUED A HDG OF 195 DEGS AFTER TKOF (TKOF RWY 21C). TKOF WAS BEHIND AN AIRBUS 320. WAKE TURB WAS ENCOUNTERED AT APPROX 500 FT AGL. CAPT WAS HAND FLYING AT THIS TIME AND CONCENTRATED ON ACFT CTL. TWR ASKED US TO CONTACT DEP CTL. CAPT NOTICED FO WAS EXPERIENCING DIFFICULTY IN CONTACTING DEP CTL. CONTACT WITH DEP CTL WAS MADE AND DEP CTL REPLIED RADAR CONTACT 10 MI SW OF DTW. ANOTHER TURN WAS ISSUED BY DEP CTL. NO FURTHER WAKE TURB WAS EXPERIENCED AND AUTOPLT WAS THEN ENGAGED. THEN AT APPROX 10500 FT, DEP CTL ADVISED US TO MAINTAIN 10000 FT. FO REPLIED BACK WE WERE ALREADY ABOVE 10000 FT. CAPT STOPPED CLB, DISENGAGED AUTOPLT AND STARTED DSCNT TO 10000 FT. TCASII ADVISED DSND, AFTER THE DSCNT HAD ALREADY BEEN INITIATED. WHEN WE LEVELED AT 10000 FT, RA STOPPED. FO STATED THAT HE HAD CHKED IN WITH DEP CTL STATING 'OUT OF 6400 FT FOR 12000 FT.' APPARENTLY NO CORRECTION OF AN ERRONEOUS ALT WAS CAUGHT BY EITHER CLRNC DELIVERY OR DEP CTL. THE CREW HAD NO REASON TO SUSPECT ANYTHING WAS WRONG AND NOT TO FLY TO THE ALT OF 12000 FT. THE HUMAN ERROR IN THIS SIT IS THE DIFFICULTY IN THE 10000 FT, 11000 FT, AND 12000 FT READBACKS TO CLRNC DELIVERY. ALSO, DEP CTL NOT CATCHING THE 12000 FT ALT READBACK. SOMETIMES THINGS ARE HEARD SO OFTEN AND REPEATEDLY, THAT YOU MIGHT HEAR WHAT YOU EXPECT TO HEAR REGARDLESS OF WHAT IS REALLY SAID. UNFORTUNATELY, FLCS ARE OFTEN PRONE NOT TO QUESTION CLRNCS GIVEN TO THEM BY ATC. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES THAT THE WAKE TURB INCIDENT WAS NOT DRAMATIC BUT HIS ATTN FOCUSED ON ASSURING CTL OF THE ACFT IN CASE THE WAKE TURB BECAME WORSE. THIS KIND OF WAKE TURB EXPERIENCE IS NOT ABNORMAL IN A BUSY DEP ENVIRONMENT. IT WAS BRIEF AND HE MAINTAINED ACFT CTL. THE ALT PROB WAS A COMPLETE CONFUSION COM ISSUE.

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.