DUNCAN AVIATION, INC.

DISCOVERED LT CENTER VERTICAL SPAR CAP CRACKED.

THE ADC SWITCHING/ANNUNCIATOR PANEL DEVELOPED A HIGH RESISTANCE SHORT TO GROUND WHICH IN TURN OVERLOADED THE CIRCUIT IN THE AC AND CAUSED THE (A) ESSENTIAL BUS TIE BREAKER TO TRIP. LETTER 2/8/2008 FOR DETAILS. THIS PART WAS INSTALLED AS PART OF STC-STO1199NY-D DUAL ALTIMETER SYSTEM AS PART OF THE RVSM SOLUTION FOR THIS AC.

DURING TAXI OPERATION FOLLOWING LANDING, THE PIC EXPERIENCED A FAILURE OF THE AIRCRAFT BRAKING SYSTEM AFTER COMPLETION OF A RT 90 DEGREE TURN. THE SIC THEN ATTEMPTED TO UTILIZE THE NORMAL BRAKING SYSTEM WITH SIMILAR RESULTS. THE PIC THEN ACTUATED THE EMERGENCY BRAKING SYSTEM TO STOP THE AIRCRAFT. SUBSEQUENT TROUBLESHOOTING DISCLOSED ERRATIC OPERATION OF THE RT MLG SAFETY SWITCH WHICH DISPLAYED FLUCTUATING RESISTANCE READINGS FROM 1.5 OHMS TO 600 OHMS. THE RT MLG SAFETY SWITCH WAS REPLACED, OPERATIONALLY TESTED AND THE AIRCRAFT APPROVED FOR RETURN TO SERVICE. REVIEW OF THE AIRCRAFT MAINTENANCE RECORDS COULD NOT ESTABLISH THAT THE SWITCH HAD EVER BEEN REPLACED. (K)

THE SECONDARY YAW SERVO CABLE KEEPER WAS RUBBING THE PRIMARY YAW SERVO CABLE ON THE RT SIDE CAUSING EXCESSIVE WEAR ON BOTH COMPONENTS.

AIRCRAFT ARRIVED FOR INSPECTION WITH STRONG FUEL ODOR IN CABIN AND FUEL LEAKING FROM BELLY SKIN SEAM. FOUND AFT CABIN CARPET SOAKED WITH FUEL. REMOVED TRIM FROM RIGHT AFT DOOR PEST AREA, FOUND THAT AILERON CABLE HAD BEEN CHAFING ON THE FUEL LINE IN THIS AREA FOR QUITE SOME TIME AND FINALLY CHAFED THROUGH LINE. REMOVED AND REPLACED FUEL LINE. INSPECTED AILERON CABLE AND FOUND TO BE SERVICEABLE. RECOMMEND A ONE TIME INSPECTION OF THIS AREA, LEFT AND RIGHT SIDES, TO SEE IF CHAFING CONDITION EXISTS.

IMPROPER TEMPERATURE PROBE INSTALLED FOR THIS PN BATTERY. TEMERATURE PROBES HAVE BEEN ROUTINELY INSTALLED WITHOUT SPECIFIC APPROVAL TO DO SO.

DURING REPLACEMENT OF LT FAIRING STRUT PLATE, FOUND AN OLD SHIM INSTALLED BETWEEN BEARING ITEM 145 AND PLATE ITEM 135 ON THE LOWER LEG OF THE LT SIDESTAY LOOKING IN HAWKER ILLUSTRATED PARTS LISTING 32-10-00-30, PAGE 0. THERE SHOULD NOT BE A SHIM INSTALLED BETWEEN ITEM 145 AND ITEM 135. DURING THE INVESTIGATING OF THE .060 INCH SHIM, FOUND SHIM TO HAVE DEEP BRINELLING FROM RIDING ON BEARING. IN LOOKING IN THE IPC, WAS NOT ABLE TO FIND .060 INCH SHIM LISTED. THE ONLY SHIMS LISTED WERE .040 INCH, .020 INCH, .050 INCH, AND .010 INCH SHIMS; THEREFORE, AN IMPROPER SHIM WAS INSTALLED ON THE LT SIDESTAY. THIS AREA OF THE SIDESTAY SHOULD BE INSPECTED DURING THE REMOVAL OF SIDESTAY OR AT 48-MONTH INSPECTION.

DURING WINDSHIELD SEAL REPLACEMENT, NUMEROUS SCREWS ALONG LOWER PORTION OF WINDSHIELD RETAINER WERE FOUND SEVERELY RUSTED THROUGH APPROXIMATELY 50 PERCENT OF ORIGINAL DIAMETER. SUSPECT CAUSE IS MOISTURE INFILTRATION AROUND RETAINER WHEN SEAL DETERIORATES BETWEEN RETAINER AND WINDSHIELDS.

DURING A VISUAL INSPECTION OF THE ELEVATOR QUADRANT, WHILE POWDER WAS NOTED AROUND THE UPPER CONTROL CABLE ATTACH POINT BARREL. REMOVAL OF BOTH CABLES FOUND DEEP CORROSION IN THE CONTROL CABLE ATTACH POINTS ON THE QUADRANT. THE 2400-HOUR, 24- AND 48-MONTH INSPECTIONS CALL OUT FOR AN INSPECTION OF COMPONENTS AND CABLES IN THE HORIZONTAL STABILIZER AREA. NOTHING ABOUT REMOVING CABLES. WITHOUT REMOVING THE CONTROL CABLES AND BARRELS FROM QUADRANT, THIS AREA WOULD NOT BE LOOKED AT.