AN MD88 ON TKOF AT 100 FT EXPERIENCED A HDG SPLIT OF 30 DEGS AND HAD A HDG ERROR WARNING MESSAGE CAUSED BY A PAX ELECTRONIC DEVICE.

Narrative

IMMEDIATELY AFTER TKOF; FLT MODE ANNUNCIATOR DISPLAYED A HDG ERROR MESSAGE AND A NO AUTOLAND MESSAGE WITH A 30 DEG HDG SPLIT IN R AND L HDG SYS WITH CENTRAL AIR DATA COMPUTER #2 SELECTED. IN THE ENSUING CONFUSION WE DISCOVERED THAT THE STANDBY COMPASS MIRROR IN THE STANDBY COMPASS HOUSING (LOCATED BEHIND AND ABOVE THE FO) WAS NOT PROPERLY ADJUSTED. THIS FORCED THE PNF TO LEAVE HIS SEAT TO READ THE STANDBY COMPASS TO DETERMINE IF SYS #1 OR #2 WAS GOOD. SYS #1 WAS IN AGREEMENT WITH STANDBY COMPASS SO WE SELECTED CADC SWITCH TO BOTH ON #1 SOLVING THE IMMEDIATE PROB. WE ALSO MADE A PA REQUESTING THAT ALL PORTABLE ELECTRONIC DEVICES BE TURNED OFF. THE ABNORMAL PROC FOR HDG ERRORS WAS FOLLOWED TO NO AVAIL. ABOUT 10-15 MINS AFTER THE PA ABOUT PED'S WHEN THE FLT ATTENDANTS RPTED THAT ALL PED'S WERE OFF; THE ERROR CORRECTED ITSELF AND SYS WERE RESTORED TO NORMAL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS AN MD88 AND WAS EQUIPPED WITH AN AHRS HDG SYS. THE RPTR SAID SHORTLY AFTER THE ANNOUNCEMENT TO TURN OFF ALL ELECTRONIC DEVICES THE 30 DEG ERROR WAS GONE AND THE SYS OPERATED NORMALLY. THE RPTR STATED THE DEVICE CAUSING THE PROB WAS NEVER IDENTED.