Narrative:

We were being vectored for an ILS to runway 18R (course 176 degrees) at ZME. Approach vectored us through the localizer for runway 18R on a heading of 150 degrees. To intercept, we were then turned to a heading of 200 degrees. We were 1 to 1 1/2 mi east of the final approach course. After rolling wings level on heading 200 degrees, I selected VOR localizer mode on the flight control panel. The autoplt started a 25 degree bank to the right. After reaching a heading of 230 degrees and still turning, I disconnected the autoplt and turned left for a more reasonable intercept angle. As I got established on the localizer, the authorities, which had been maintaining final approach speed, (135 KTS) advanced to limit. The airplane gained about 300 ft before we were able to disconnect the autothrottles and lower the nose of the airplane to recapture the altitude. At no time was any know autoflt parameter reached that would trigger the 'self protection' modes. Events described are unexplained, and maintenance checks of the airplane were normal. I was prepared for the localizer capture problem, but I was not prepared for the autothrottle event, and should have been more aggressive correcting the altitude change.

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Original NASA ASRS Text

Title: CARGO WDB HAS AUTOPLT AND AUTOTHROTTLE PROBS. ALTDEV HDG DEV, SPD DEV.

Narrative: WE WERE BEING VECTORED FOR AN ILS TO RWY 18R (COURSE 176 DEGS) AT ZME. APCH VECTORED US THROUGH THE LOC FOR RWY 18R ON A HDG OF 150 DEGS. TO INTERCEPT, WE WERE THEN TURNED TO A HDG OF 200 DEGS. WE WERE 1 TO 1 1/2 MI E OF THE FINAL APCH COURSE. AFTER ROLLING WINGS LEVEL ON HDG 200 DEGS, I SELECTED VOR LOC MODE ON THE FLT CTL PANEL. THE AUTOPLT STARTED A 25 DEG BANK TO THE R. AFTER REACHING A HDG OF 230 DEGS AND STILL TURNING, I DISCONNECTED THE AUTOPLT AND TURNED L FOR A MORE REASONABLE INTERCEPT ANGLE. AS I GOT ESTABLISHED ON THE LOC, THE AUTHORITIES, WHICH HAD BEEN MAINTAINING FINAL APCH SPD, (135 KTS) ADVANCED TO LIMIT. THE AIRPLANE GAINED ABOUT 300 FT BEFORE WE WERE ABLE TO DISCONNECT THE AUTOTHROTTLES AND LOWER THE NOSE OF THE AIRPLANE TO RECAPTURE THE ALT. AT NO TIME WAS ANY KNOW AUTOFLT PARAMETER REACHED THAT WOULD TRIGGER THE 'SELF PROTECTION' MODES. EVENTS DESCRIBED ARE UNEXPLAINED, AND MAINT CHKS OF THE AIRPLANE WERE NORMAL. I WAS PREPARED FOR THE LOC CAPTURE PROB, BUT I WAS NOT PREPARED FOR THE AUTOTHROTTLE EVENT, AND SHOULD HAVE BEEN MORE AGGRESSIVE CORRECTING THE ALT CHANGE.

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.