Narrative:

At the end of all night 'red-eye' flight we made the turn to final approach at dtw. Captain was flying by hand. Due to a clean confign turn with slightly excessive bank angle (35 degrees), his flight director never stabilized. He proceeded to fly the intercept to final and final on a flight director still 'searching,' seemingly ignoring raw data. Since approximately 20 degrees of bank was commanded, the flight director kept 'searching,' commanding turns back and forth across the approach course. After several suggestions (using CRM assertive statements) to roll out on raw data, I (first officer) suggested that I assume control of the aircraft since my instruments were ok. I evaluated his as ok as well or I would have insisted on immediate go around. When I took control aircraft was about 700 ft AGL 1 1/2 DOT deviation from centerline, fully configured, on glide path 10-15 KTS above vga (approach speed). I made a fairly radical maneuver back to centerline and we broke out at about 500 ft AGL. The so assisted with visual calls to get back to centerline. I corrected and made a normal landing. If we did not break out when we did I was going to go around. Suggestions: captain should have flown raw data immediately when anyone in crew noticed a problem. A lot of prompting was done by the other crew members. The prompting should have been more direct before the situation was allowed to progress to the point that it had. A go around should have be initiated when the situation progressed to even a thought of 'unsafe' came to mind.

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Original NASA ASRS Text

Title: HDG TRACK DEV IN A DE-STABILIZED APCH.

Narrative: AT THE END OF ALL NIGHT 'RED-EYE' FLT WE MADE THE TURN TO FINAL APCH AT DTW. CAPT WAS FLYING BY HAND. DUE TO A CLEAN CONFIGN TURN WITH SLIGHTLY EXCESSIVE BANK ANGLE (35 DEGS), HIS FLT DIRECTOR NEVER STABILIZED. HE PROCEEDED TO FLY THE INTERCEPT TO FINAL AND FINAL ON A FLT DIRECTOR STILL 'SEARCHING,' SEEMINGLY IGNORING RAW DATA. SINCE APPROX 20 DEGS OF BANK WAS COMMANDED, THE FLT DIRECTOR KEPT 'SEARCHING,' COMMANDING TURNS BACK AND FORTH ACROSS THE APCH COURSE. AFTER SEVERAL SUGGESTIONS (USING CRM ASSERTIVE STATEMENTS) TO ROLL OUT ON RAW DATA, I (FO) SUGGESTED THAT I ASSUME CTL OF THE ACFT SINCE MY INSTS WERE OK. I EVALUATED HIS AS OK AS WELL OR I WOULD HAVE INSISTED ON IMMEDIATE GAR. WHEN I TOOK CTL ACFT WAS ABOUT 700 FT AGL 1 1/2 DOT DEV FROM CTRLINE, FULLY CONFIGURED, ON GLIDE PATH 10-15 KTS ABOVE VGA (APCH SPD). I MADE A FAIRLY RADICAL MANEUVER BACK TO CTRLINE AND WE BROKE OUT AT ABOUT 500 FT AGL. THE SO ASSISTED WITH VISUAL CALLS TO GET BACK TO CTRLINE. I CORRECTED AND MADE A NORMAL LNDG. IF WE DID NOT BREAK OUT WHEN WE DID I WAS GOING TO GAR. SUGGESTIONS: CAPT SHOULD HAVE FLOWN RAW DATA IMMEDIATELY WHEN ANYONE IN CREW NOTICED A PROBLEM. A LOT OF PROMPTING WAS DONE BY THE OTHER CREW MEMBERS. THE PROMPTING SHOULD HAVE BEEN MORE DIRECT BEFORE THE SITUATION WAS ALLOWED TO PROGRESS TO THE POINT THAT IT HAD. A GAR SHOULD HAVE BE INITIATED WHEN THE SITUATION PROGRESSED TO EVEN A THOUGHT OF 'UNSAFE' CAME TO MIND.

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.