Service difficulty report · J-Box · Pilats PC1247E

Difficulty date
February 25, 2012
Submitted
September 14, 2015
Operation
General aviation
Make and model
Pilats PC1247E
Aircraft time
38 hours
Engine
Pwa PT6A67
Propeller
Hartzl HCE4A3D
Part
J-Box
Part number
974033814
Condition
Loose
Part time
1,143 hours
Stage of operation
NR
How discovered
9
Nature of condition
O
Precautionary procedure
O

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

(CAN) ON FEB 17, AT 1131.6 HRS, A DEFECT WAS RECORDED FOR BATTERY ASSIST NOT FUNCTIONING, SECONDARY START, WHICH WAS RECTIFIED BY REPLACEMENT OF THE LHPJB. ON FEB 25 AT 1142.8 HRS A DEFECT WAS RECORDED: GEN 1 BUS CAS MESSAGE, UNABLE TO CLEAR. WHILE CONDUCTING TROUBLESHOOTING WITH EXTERNAL POWER ON, THE BATTERY 1 VOLTAGE DRAINED DOWN BELOW 20V. DURING FURTHER TROUBLESHOOTING IT WAS CONFIRMED BATTERY 1 GENERALLY WOULD NOT CHARGE WITH EXTERNAL POWER CONNECTED AND WOULD CONTINUE TO DISCHARGE, WITH EXCEPTION OF A FEW INSTANCES WHEN BAT 1 WOULD RECEIVE A PARTIAL CHARGE (APPROX 27 V FROM A 28.5 EXT POWER UNIT). DURING ENGINE RUNS IT WAS ALSO CONFIRMED THAT THE SECONDARY START SEQUENCE WAS NOT FUNCTIONING ADDITIONALLY THERE WAS NO LOAD SHARING WHEN GEN 1 OR GEN 2 WAS TURNED OFF LINE, IT WAS SUSPECTED THE BUS TIE WAS NOT CLOSING. EXTENSIVE TROUBLE SHOOTING WAS CARRIED OUT WITH NO FAULTS FOUND. THE L/H POWER JUNCTION BOX WAS REPLACED WITH NIL FIX. WHILE REMOVING THE R/H POWER JUNCTION BOX FOR REPLACEMENT THE TWO REAR CONNECTIONS AT T2 AND T3 WERE FOUND TO BE SIGNIFICANTLY LOOSE AND ARCING ON THE LUGS. THE LUGS WERE TIGHTENED AND THE SYSTEM TESTED SERVICEBALE. THE JUNCTION BOX REPLACED DUE TO TERMINAL LUG DAMAGE.