AN F900 CREW DECLARED AN EMER AND DIVERTED FOLLOWING ELECTRICAL SMOKE WITH A POPPED CB.

Narrative

WHILE CLBING THROUGH FL300 I HEARD A CIRCUIT BREAKER POP AND ASKED THE PF IF SHE HEARD THE CB. BEFORE SHE COULD REPLY MY NOSE FILLED WITH A STRONG ELECTRICAL BURNING SMELL. I DONNED MY O2 MASK AND LOOKED AROUND FOR SMOKE AND TRIED TO LOCATE THE POPPED CB. I FOUND THE #2 ADF CB POPPED AND NOTED THE LIGHTS WERE OUT ON THIS UNIT. I SHUT DOWN THE ADJACENT ADF AND PULLED THE APPROPRIATE CB. IT APPEARED AS THOUGH WE HAD A SMALL AMOUNT OF SMOKE IN THE LOWER PORTION OF THE COCKPIT. AFTER OPENING THE AIR VENTS THE SMOKE AND SMELL CLRED. WE LEVELED AT FL350 PER ATC AND BEGAN TO ASSESS OUR SITUATION. O2 MASKS WERE NOT NEEDED AND THE SITUATION SEEMED TO BE RESOLVED WITH A FAILED ADF NAV BOX. HOWEVER; WITHIN TWO MINUTES THE STRONG SMELL RETURNED. I DETERMINED IT WAS TIME TO LAND AND HAVE THE ACFT CHECKED FOR FURTHER PROBS. NO FIRE WAS NOTED AND THE SMELL SEEMED TO COME AND GO. I CALLED CTR AND ADVISED WE HAD ELECTRICAL PROBS AND NEEDED TO MAKE A PRECAUTIONARY RETURN TO ZZZ (I FELT THIS WAS BEST LOCATION FOR EMERGENCY SUPPORT IF CONDITIONS WORSENED; PAX AIRLINE TRAVEL AND ALSO MAINT ON THE ACFT). CTR TURNED US NORTH AND BEGAN COORD OF A CLRNC TO ZZZ. I CALLED THE CABIN ATTENDANT FORWARD AND EXPLAINED OUR SITUATION AND PLAN OF ACTION AND ASKED HER TO ADVISE THE PAX WE WERE RETURNING TO ZZZ FOR A MAINT PROB. BY THIS TIME THE PAX HAD ALSO SMELLED THE BURNING FROM THE COCKPIT. WE WERE CLRED TO FIX AND THE ARR. AFTER CHANGING THE DEST IN THE FMS TO ZZZ; I ATTEMPTED TO LOAD THE ARR. THE FMS ONLY LISTED TWO PAGES OF ARRS AND DID NOT LIST THE ARR. WE WERE ASSIGNED TO DESCEND VIA THE ARR SO I BEGAN LOADING THE WAYPOINTS WE WERE TURNED TO AND ALTS MANUALLY WHILE ALREADY ON THE ARR. THE ACFT IS EQUIPPED WITH SMALL EFBS AND NO PAPER CHARTS WHICH MADE READING AND LOADING THIS ARR MANUALLY VERY DIFFICULT AT NIGHT. ALL WAYPOINTS WERE LOADED UP TO THE FINAL ROUTING AS THE RWY WAS NOT ASSIGNED UNTIL LATE IN THE ARR. DUE TO THE SMALL SIZE OF PRINT ON THE EFB I HAD TO ZOOM INTO THE SCREEN TO READ THE DATA. ONCE CLRED FOR THE RWY AND SETTING UP THE ILS FREQUENCIES; I RETURNED TO THE EFB TO TRY AND LOCATE THE REST OF THE WAYPOINTS AND ALT INFO. THE LAST WAYPOINT ALT LOADED WAS DEF AT 12000 FT. I DID NOT GET THE ALTS AT EFG OR FGH LOADED AS I DID NOT SEE THIS PART OF THE PLATE DUE TO ZOOMING IN TO THE ARR PORTION AND LATER PULLING UP THE ILS PLATES FOR THE RWY WHICH ALSO DO NOT LIST THE ALTS AT THESE TWO POINTS. I TRIED TO ASK ATC FOR HELP WITH ALTS BECAUSE I KNEW WE WERE BEHIND AND PROBABLY MISSING A RESTR. ATC WAS BUSY AND MUST NOT HAVE RECEIVED MY CALL. THE PF WAS HAVING TROUBLE WITH ILS GS GUIDANCE SO I WENT HEADS DOWN TO CONFIRM PROPER FREQS. ALL WAS SET OK AND WE HAD LOC GUIDANCE BUT NO GS INFO. WEATHER WAS GOOD VMC AND WE PICKED UP THE ARPT VISUALLY AND LANDED. I CALLED CTR AND APCH AND DISCUSSED OUR PROBS WITH THE CTLRS. THEY CONFIRMED WE DID MISS THE ALT RESTRS ON THE FINAL PORTION BUT NO TFC CONFLICTS EXISTED. THEY THANKED ME FOR MY CALL AND RECOGNITION OF OUR PROBS. THE CTLR SAID; 'WE KNEW YOU WERE HAVING DIFFICULTIES DUE TO YOUR ELECTRICAL PROB.' I FOUND THE EFBS TO BE INADEQUATE FOR ME IN A TIME COMPRESSED POSSIBLE EMER SITUATION. TOO MUCH INFO NEEDED TO BE EXTRACTED FROM A VERY SMALL SCREEN IN A SHORT TIME SPAN. SITUATIONAL AWARENESS WAS LOST BECAUSE OF ZOOMING IN TO READ THE SCREEN -- OTHER PARTS OF THE CHART WERE MISSED. IN RETROSPECT; EVEN THOUGH ATC WAS BUSY WITH ARRS; I SHOULD HAVE REQUESTED MORE ASSISTANCE FROM ATC.