Narrative:

Flight was from atl-dtw. We were flying the mizar 1 arrival into dtw and in a descent. We were talking to ZOB and then metropolitan-approach control. While descending to FL210 aircraft lost its altitude capture when I selected a different mode on the autoplt. Realizing my mistake, I immediately selected a climb on the autoplt while the aircraft continued to descend. When the autoplt didn't respond I pulled the yoke to return the aircraft to the assigned altitude. Excessive force was necessary to bring the aircraft back to level flight and maintain altitude. (Autoplt had trimmed the aircraft to an almost full nose-down position.) after leveling at FL210 (lowest altitude was 20.6) and reducing stick forces, autoplt was disconnected and the jet was trimmed using normal trim. (Alternate trim didn't respond.) during all this we were given numerous heading and altitude changes. Then, we were turned to an intercept heading, told to rejoin the arrival on the inbound radial to mizar, descend and maintain 12000 ft, given a clearance to depart, what we understood to be razim, on a 040 degree heading and finally given a frequency change to approach control. (All of this was in the same radio transmission.) after departing razim on a 040 degree heading, we had flown 10-15 NM before approach control asked what fix we had taken the 040 degree heading from. We told him razim. He told us it was supposed to be mizar. To add to all this confusion we were flying around a line of thunderstorms that was rapidly approaching the airport from the west (reports of severe turbulence, gusts up to 50 KTS and 1 inch hail). The rest of the approach and landing were uneventful. The WX was of concern to us, in not only avoiding it but in that we might not be able to get into dtw. Some suggestions from my viewpoint in preventing a similar situation. Use the stars and let the pilots fly them. They are set up to help traffic flow and reduce controller workload so use them. Radio xmissions should follow the guidelines in the aim. Too much information in a radio transmission can cause some important information to be missed or misinterpreted. In the future I will slow the process down when getting information overload.

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Original NASA ASRS Text

Title: MLG MISHEARS INTXN NAME, HDG DEV.

Narrative: FLT WAS FROM ATL-DTW. WE WERE FLYING THE MIZAR 1 ARR INTO DTW AND IN A DSCNT. WE WERE TALKING TO ZOB AND THEN METRO-APCH CTL. WHILE DSNDING TO FL210 ACFT LOST ITS ALT CAPTURE WHEN I SELECTED A DIFFERENT MODE ON THE AUTOPLT. REALIZING MY MISTAKE, I IMMEDIATELY SELECTED A CLB ON THE AUTOPLT WHILE THE ACFT CONTINUED TO DSND. WHEN THE AUTOPLT DIDN'T RESPOND I PULLED THE YOKE TO RETURN THE ACFT TO THE ASSIGNED ALT. EXCESSIVE FORCE WAS NECESSARY TO BRING THE ACFT BACK TO LEVEL FLT AND MAINTAIN ALT. (AUTOPLT HAD TRIMMED THE ACFT TO AN ALMOST FULL NOSE-DOWN POS.) AFTER LEVELING AT FL210 (LOWEST ALT WAS 20.6) AND REDUCING STICK FORCES, AUTOPLT WAS DISCONNECTED AND THE JET WAS TRIMMED USING NORMAL TRIM. (ALTERNATE TRIM DIDN'T RESPOND.) DURING ALL THIS WE WERE GIVEN NUMEROUS HDG AND ALT CHANGES. THEN, WE WERE TURNED TO AN INTERCEPT HDG, TOLD TO REJOIN THE ARR ON THE INBOUND RADIAL TO MIZAR, DSND AND MAINTAIN 12000 FT, GIVEN A CLRNC TO DEPART, WHAT WE UNDERSTOOD TO BE RAZIM, ON A 040 DEG HDG AND FINALLY GIVEN A FREQ CHANGE TO APCH CTL. (ALL OF THIS WAS IN THE SAME RADIO XMISSION.) AFTER DEPARTING RAZIM ON A 040 DEG HDG, WE HAD FLOWN 10-15 NM BEFORE APCH CTL ASKED WHAT FIX WE HAD TAKEN THE 040 DEG HDG FROM. WE TOLD HIM RAZIM. HE TOLD US IT WAS SUPPOSED TO BE MIZAR. TO ADD TO ALL THIS CONFUSION WE WERE FLYING AROUND A LINE OF TSTMS THAT WAS RAPIDLY APCHING THE ARPT FROM THE W (RPTS OF SEVERE TURB, GUSTS UP TO 50 KTS AND 1 INCH HAIL). THE REST OF THE APCH AND LNDG WERE UNEVENTFUL. THE WX WAS OF CONCERN TO US, IN NOT ONLY AVOIDING IT BUT IN THAT WE MIGHT NOT BE ABLE TO GET INTO DTW. SOME SUGGESTIONS FROM MY VIEWPOINT IN PREVENTING A SIMILAR SIT. USE THE STARS AND LET THE PLTS FLY THEM. THEY ARE SET UP TO HELP TFC FLOW AND REDUCE CTLR WORKLOAD SO USE THEM. RADIO XMISSIONS SHOULD FOLLOW THE GUIDELINES IN THE AIM. TOO MUCH INFO IN A RADIO XMISSION CAN CAUSE SOME IMPORTANT INFO TO BE MISSED OR MISINTERPRETED. IN THE FUTURE I WILL SLOW THE PROCESS DOWN WHEN GETTING INFO OVERLOAD.

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.