Narrative:

Cleared to FL290 and direct mkg. First officer flying with autoplt engaged and omega navigation track engaged. Climbing through FL237 aircraft rolled rapidly into 30 degree angle bank turn to the left, away from msk. Simultaneously, CAWS system issued an overspd warning and TCASII issued a 'traffic climb' advisory. Indications were traffic minus 700 ft below us and TCASII indicated a 300 FPM climb. First officer disconnected autoplt and automatic throttles maintaining called for climb and reversing aircraft back toward mkg VOR. I initiated radio call to ZAU to advise them of RA. In meantime, airspeed had decayed and I saw aircraft was descending. RA was in 'clear' mode at this time, showing previous aircraft traffic now 800 ft below us. I advised first officer not to descend but to climb, which he promptly did. Lowest altitude reached was FL233. All omega wp's were verified and aircraft was tracking normally when it suddenly turned away from mkg (as backed up by VOR). Likewise, first officer was climbing, aircraft in IAS mode of autoplt (320 KTS). As aircraft turned away from mkg, IAS went to 360 KIAS and aircraft nose dropped. Omega was not used for active navigation remainder of flight, but xref to VOR navigation appeared to be giving correct indications. Autoplt and automatic throttle were re-engaged and worked normally in all modes, 'IAS hold' included, remainder of flight. Altitude loss from FL240 to FL233 was primarily due to distraction of multiple loud aural warnings and unexpected transition from autoplt use to hand flying. Incident reported to maintenance for follow-up. ATC had not issued any previous TA's.

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Original NASA ASRS Text

Title: LGT HAS ELECTRONIC EQUIP PROB AND TCASII ALERT ON CLBOUT. RESULT: HDG DEV, ALTDEV.

Narrative: CLRED TO FL290 AND DIRECT MKG. FO FLYING WITH AUTOPLT ENGAGED AND OMEGA NAV TRACK ENGAGED. CLBING THROUGH FL237 ACFT ROLLED RAPIDLY INTO 30 DEG ANGLE BANK TURN TO THE L, AWAY FROM MSK. SIMULTANEOUSLY, CAWS SYS ISSUED AN OVERSPD WARNING AND TCASII ISSUED A 'TFC CLB' ADVISORY. INDICATIONS WERE TFC MINUS 700 FT BELOW US AND TCASII INDICATED A 300 FPM CLB. FO DISCONNECTED AUTOPLT AND AUTO THROTTLES MAINTAINING CALLED FOR CLB AND REVERSING ACFT BACK TOWARD MKG VOR. I INITIATED RADIO CALL TO ZAU TO ADVISE THEM OF RA. IN MEANTIME, AIRSPD HAD DECAYED AND I SAW ACFT WAS DSNDING. RA WAS IN 'CLR' MODE AT THIS TIME, SHOWING PREVIOUS ACFT TFC NOW 800 FT BELOW US. I ADVISED FO NOT TO DSND BUT TO CLB, WHICH HE PROMPTLY DID. LOWEST ALT REACHED WAS FL233. ALL OMEGA WP'S WERE VERIFIED AND ACFT WAS TRACKING NORMALLY WHEN IT SUDDENLY TURNED AWAY FROM MKG (AS BACKED UP BY VOR). LIKEWISE, FO WAS CLBING, ACFT IN IAS MODE OF AUTOPLT (320 KTS). AS ACFT TURNED AWAY FROM MKG, IAS WENT TO 360 KIAS AND ACFT NOSE DROPPED. OMEGA WAS NOT USED FOR ACTIVE NAV REMAINDER OF FLT, BUT XREF TO VOR NAV APPEARED TO BE GIVING CORRECT INDICATIONS. AUTOPLT AND AUTO THROTTLE WERE RE-ENGAGED AND WORKED NORMALLY IN ALL MODES, 'IAS HOLD' INCLUDED, REMAINDER OF FLT. ALT LOSS FROM FL240 TO FL233 WAS PRIMARILY DUE TO DISTR OF MULTIPLE LOUD AURAL WARNINGS AND UNEXPECTED TRANSITION FROM AUTOPLT USE TO HAND FLYING. INCIDENT RPTED TO MAINT FOR FOLLOW-UP. ATC HAD NOT ISSUED ANY PREVIOUS TA'S.

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.