Narrative:

About 12 mins into the flight from ZZZ1 to ZZZ2, we were cruising at FL200 near ZZZ VOR. We experienced a total electrical failure. All screens went black. Only the standby instruments were powered. We had no indication of main battery power. We maintained altitude for approximately two minutes and then decided that we had better get on the ground as soon as possible. I started a 2200 FPM descent an headed for ZZZ. During the descent, I tried to get the main batteries back on line with no success. I then depressed the right generator button and we regained power on that side. With power restored to the right side, the power distribution panel said both main batteries were selected off. I was then able to successfully connect the main batteries. Ten miles from ZZZ, we were cleared to land by ZZZ approach. On base, we were able to restore the left generator. Because of power failure we were not able to contact center and notify them of our situation until power was restored (approximately 6000 ft MSL). At ZZZ, the plane was promptly examined by learjet and we are awaiting an explanation on how we could lose both generators and disconnect both batteries at the same time. Callback conversation with reporter revealed the following information: the reporter stated the loss of power was almost instantaneous. First one dc generator failed then the second generator failed, followed by both ship's main batteries disconnecting from the battery bus. The reporter said the standby instruments were operative from the standby emergency battery. The reporter stated that power was gradually restored during descent and an emergency was declared. The reporter said the aircraft was turned over to manufacturer's service center for investigation of the electrical power loss and the results were surprising. The reporter stated it was discovered that static electrical discharge in the bus power control computers tripped the generators and both ship's main batteries. The reporter stated both main ship's batteries were also found weak and under voltage. The reporter said the static discharge wicks were installed on top of the aircraft surface paint and were not bonded to the aircraft structure, so the static charge discharged inside the aircraft. The reporter stated the manufacturer advised only one other occurrence of this nature had been experienced on this model and static discharge wicks were the cause.

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Original NASA ASRS Text

Title: A LEAR 45 IN CRUISE AT FL200 EXPERIENCED A TOTAL ELECTRICAL FAILURE. DC GENERATORS AND MAIN SHIPS BATTERIES. ONLY STANDBY INSTRUMENTS WERE POWERED.

Narrative: ABOUT 12 MINS INTO THE FLIGHT FROM ZZZ1 TO ZZZ2, WE WERE CRUISING AT FL200 NEAR ZZZ VOR. WE EXPERIENCED A TOTAL ELECTRICAL FAILURE. ALL SCREENS WENT BLACK. ONLY THE STANDBY INSTS WERE POWERED. WE HAD NO INDICATION OF MAIN BATTERY POWER. WE MAINTAINED ALT FOR APPROX TWO MINUTES AND THEN DECIDED THAT WE HAD BETTER GET ON THE GROUND ASAP. I STARTED A 2200 FPM DSCNT AN HEADED FOR ZZZ. DURING THE DSCNT, I TRIED TO GET THE MAIN BATTERIES BACK ON LINE WITH NO SUCCESS. I THEN DEPRESSED THE R GENERATOR BUTTON AND WE REGAINED POWER ON THAT SIDE. WITH POWER RESTORED TO THE R SIDE, THE POWER DISTRIBUTION PANEL SAID BOTH MAIN BATTERIES WERE SELECTED OFF. I WAS THEN ABLE TO SUCCESSFULLY CONNECT THE MAIN BATTERIES. TEN MILES FROM ZZZ, WE WERE CLEARED TO LAND BY ZZZ APCH. ON BASE, WE WERE ABLE TO RESTORE THE L GENERATOR. BECAUSE OF POWER FAILURE WE WERE NOT ABLE TO CONTACT CENTER AND NOTIFY THEM OF OUR SITUATION UNTIL POWER WAS RESTORED (APPROX 6000 FT MSL). AT ZZZ, THE PLANE WAS PROMPTLY EXAMINED BY LEARJET AND WE ARE AWAITING AN EXPLANATION ON HOW WE COULD LOSE BOTH GENERATORS AND DISCONNECT BOTH BATTERIES AT THE SAME TIME. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE LOSS OF POWER WAS ALMOST INSTANTANEOUS. FIRST ONE DC GENERATOR FAILED THEN THE SECOND GENERATOR FAILED, FOLLOWED BY BOTH SHIP'S MAIN BATTERIES DISCONNECTING FROM THE BATTERY BUS. THE RPTR SAID THE STANDBY INSTRUMENTS WERE OPERATIVE FROM THE STANDBY EMER BATTERY. THE RPTR STATED THAT POWER WAS GRADUALLY RESTORED DURING DESCENT AND AN EMER WAS DECLARED. THE RPTR SAID THE ACFT WAS TURNED OVER TO MANUFACTURER'S SERVICE CENTER FOR INVESTIGATION OF THE ELECTRICAL POWER LOSS AND THE RESULTS WERE SURPRISING. THE RPTR STATED IT WAS DISCOVERED THAT STATIC ELECTRICAL DISCHARGE IN THE BUS POWER CONTROL COMPUTERS TRIPPED THE GENERATORS AND BOTH SHIP'S MAIN BATTERIES. THE RPTR STATED BOTH MAIN SHIP'S BATTERIES WERE ALSO FOUND WEAK AND UNDER VOLTAGE. THE RPTR SAID THE STATIC DISCHARGE WICKS WERE INSTALLED ON TOP OF THE ACFT SURFACE PAINT AND WERE NOT BONDED TO THE ACFT STRUCTURE, SO THE STATIC CHARGE DISCHARGED INSIDE THE ACFT. THE RPTR STATED THE MANUFACTURER ADVISED ONLY ONE OTHER OCCURRENCE OF THIS NATURE HAD BEEN EXPERIENCED ON THIS MODEL AND STATIC DISCHARGE WICKS WERE THE CAUSE.

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.