AN ACR LTT HAD A LIGHTNING STRIKE FOLLOWED BY A PARTIAL INST FAILURE AND LOSS OF PROP CTL UNIT.

Narrative

FLYING SBOUND IN CLR AIR WITH WX PAINT ON RADAR TO THE W; APPROX 25 NM; AND EXPERIENCED A LIGHTNING STRIKE/STATIC DISCHARGE. APPROX 7-10 MINS LATER; THE FO'S EFIS FAILED. APPARENTLY A PARTIAL FAILURE OF THE DISPLAY PROCESSING UNIT (DPU). EFIS (AND AHRS) FUNCTIONED NORMALLY IN TRANSFER MODE. CAPT'S SIDE NOT AFFECTED. APPROX 5-7 MINS AFTER THE EFIS FAILURE; THE R ELECTRONIC ENG CTL FAILED; WHILE ON APCH (RADAR DOWNWIND TO BASE) AT EGLIN AFB (VPS). ON THE GND; THE MECH FOUND THE FLT IDLE STOP SOLENOID CIRCUIT BREAKER FOR THE R ENG WAS TRIPPED. BOTH OF THE FLT IDLE STOP CIRCUIT BREAKERS WERE VERIFIED AS CLOSED; AND A MAINT LOGBOOK ENTRY WAS MADE BY THE CAPT PER FAA AIRWORTHINESS DIRECTIVE. THIS AIRWORTHINESS DIRECTIVE; A RESPONSE TO A RECENT LTT PROP OVERSPD WHERE POST-FLT INSPECTION FOUND BOTH FLT IDLE STOP CIRCUIT BREAKERS TRIPPED -- REQUIRES OPERATORS OF THE LTT TO CHK/VERIFY THE FLT IDLE STOP CIRCUIT BREAKERS ARE CLOSED; BUT ONLY ON THE FIRST FLT OF THE DAY! THE CIRCUIT BREAKERS ARE LOCATED INSIDE THE CAPT'S SIDE PANEL; ARE INACCESSIBLE WITHOUT REMOVING THE PANEL; BUT CAN BE VIEWED THROUGH A 2 INCH SQUARE PLEXIGLAS VIEW PLATE INSTALLED IN THE PANEL. 1) WHY ONLY ON THE FIRST FLT OF THE DAY? WHY NOT EACH FLT? WE'LL NEVER KNOW IF THE STATIC DISCHARGE ACTUALLY CAUSED THE CIRCUIT BREAKER TO POP; BUT HAD WE NOT RPTED A LIGHTNING STRIKE; THE FLT IDLE STOP CIRCUIT BREAKER WOULD NOT HAVE BEEN DISCOVERED UNTIL THE NEXT MORNING. HOW ABOUT CHANGING THE AIRWORTHINESS DIRECTIVE TO A BEFORE START ITEM? 2) BETTER YET; THE LTT HAS AT LEAST 2 MAP CAPTIONS AVAILABLE FOR THE CAUTION/WARNING SYS. WIRE THE CIRCUIT BREAKERS INTO THE MAP SO THAT IF IT POPS; THE FLC KNOWS IMMEDIATELY BY RECEIVING A SINGLE CHIME AURAL WARNING; MAP CAPTION AND CAUTION LIGHT!