Narrative:

When we were taxiing to deice, I noticed both the #1 and #2 IRS attitude mode lights were illuminated. I also noticed the map display had failed. I was unsuccessful in getting the lights to go out. It appeared that the FMS was inoperative. The #1, #2 and the standby compasses were in agreement. #1, #2 and standby attitude indicators were operating normally. I decided to change our flight plan suffix from /F to /a and continue on to dfw. When we took the runway, all 3 compasses were checked to insure that they corresponded to the runway heading. Attitude indicators and flight directors were normal. After takeoff, we turned to a heading of 255 degrees. Departure control asked what our heading was. They instructed us to turn right 20 degrees. We were then cleared direct to the mxe VOR and on course. After crossing mxe, we turned left to intercept the 278 degree radial. Center asked our heading. They said we were 40 degrees off on our heading. I confirmed this with the standby compass. I asked for radar vectors and to maintain FL260. About this time, the autoplt and autothrottles disengaged. We lost the flight directors, attitude indicators, navigation displays and the RMI's. I declared an emergency and asked to maintain FL260 and our current heading while I solved the problems. All the flight instruments started working after about 30 seconds. I thought the problem was related to our FMS failure. I also noted that we now had a flashing 'align' light. I ran the 'align light flashing' checklist. This corrected the compass problems we had been experiencing. The compasses and the FMS headings as well as the standby compass all stayed in agreement for the rest of the flight to dfw.

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Original NASA ASRS Text

Title: MD80 CREW TOOK OFF WITH BOTH IRS SYS IN ATTITUDE.

Narrative: WHEN WE WERE TAXIING TO DEICE, I NOTICED BOTH THE #1 AND #2 IRS ATTITUDE MODE LIGHTS WERE ILLUMINATED. I ALSO NOTICED THE MAP DISPLAY HAD FAILED. I WAS UNSUCCESSFUL IN GETTING THE LIGHTS TO GO OUT. IT APPEARED THAT THE FMS WAS INOP. THE #1, #2 AND THE STANDBY COMPASSES WERE IN AGREEMENT. #1, #2 AND STANDBY ATTITUDE INDICATORS WERE OPERATING NORMALLY. I DECIDED TO CHANGE OUR FLT PLAN SUFFIX FROM /F TO /A AND CONTINUE ON TO DFW. WHEN WE TOOK THE RWY, ALL 3 COMPASSES WERE CHKED TO INSURE THAT THEY CORRESPONDED TO THE RWY HDG. ATTITUDE INDICATORS AND FLT DIRECTORS WERE NORMAL. AFTER TKOF, WE TURNED TO A HDG OF 255 DEGS. DEP CTL ASKED WHAT OUR HDG WAS. THEY INSTRUCTED US TO TURN R 20 DEGS. WE WERE THEN CLRED DIRECT TO THE MXE VOR AND ON COURSE. AFTER XING MXE, WE TURNED L TO INTERCEPT THE 278 DEG RADIAL. CTR ASKED OUR HDG. THEY SAID WE WERE 40 DEGS OFF ON OUR HDG. I CONFIRMED THIS WITH THE STANDBY COMPASS. I ASKED FOR RADAR VECTORS AND TO MAINTAIN FL260. ABOUT THIS TIME, THE AUTOPLT AND AUTOTHROTTLES DISENGAGED. WE LOST THE FLT DIRECTORS, ATTITUDE INDICATORS, NAV DISPLAYS AND THE RMI'S. I DECLARED AN EMER AND ASKED TO MAINTAIN FL260 AND OUR CURRENT HDG WHILE I SOLVED THE PROBS. ALL THE FLT INSTS STARTED WORKING AFTER ABOUT 30 SECONDS. I THOUGHT THE PROB WAS RELATED TO OUR FMS FAILURE. I ALSO NOTED THAT WE NOW HAD A FLASHING 'ALIGN' LIGHT. I RAN THE 'ALIGN LIGHT FLASHING' CHKLIST. THIS CORRECTED THE COMPASS PROBS WE HAD BEEN EXPERIENCING. THE COMPASSES AND THE FMS HDGS AS WELL AS THE STANDBY COMPASS ALL STAYED IN AGREEMENT FOR THE REST OF THE FLT TO DFW.

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.