PONDEROSA AVIATION, LLC

Operated by Ponderosa Aviation (per NTSB report)

Operated by PONDEROSA AVIATION LLC (per NTSB report)

Operated by PONDEROSA AVIATION INC (per NTSB report)

Operated by Ponderosa Aviation (per NTSB report)

CRACKS WERE FOUND DURING ROUTINE INSPECTION AT STATION 386.82. THIS SECTION IS LOCATED AT THE FORWARD SECTION OF THE ATTACH POINT FOR THE VERTICAL TAIL. UPON FURTHER INSPECTION OF THE REMAINING 8 AIRCRAFT 2 ADDITIONAL AIRCRAFT WERE FOUND TO HAVE MINOR CRACKING. IT APPEARS THE 2 SUPPORT BRACKET ATTACH BOLTS BECAME LOOSE WHICH WAS NOT VISIBLE TO THE EYE. AFTER SOMETIME THE LOOSE HARDWARE LEAD TO CRACKING IN THE FORWARD SECTION OF THE VERTICAL ATTACH POINT.

DME HEAD SHORTED INSIDE CAUSING SMOKE TO BE PULLED INTO AVIONICS VENTILATION SYS AND CIRCULATED TO THE ACFT CABIN.

WHILE FLYING A FIRE MISSION IN SUPPORT OF USFS, THE PILOT NOTICED THE RT GEAR START TO EXTEND FOLLOWED BY A LOSS OF HYDRAULIC PRESSURE. PILOT RETURNED TO THE AIRPORT AND LANDED. THE PROBLEM WAS TRACED TO THE RT MAIN GEAR RETRACT CYLINDER. UPON DISASSEMBLY OF THE RETRACT CYLINDER, THE O-RING AROUND THE SHAFT WAS FOUND TO BE SPLIT. THE SPLIT O-RING ALLOWED THE HYDRAULIC FLUID TO BE PUMPED OUT. THE SEALS AND O-RINGS WERE REPLACED. PROBABLE CAUSE: POSSIBLE DIRTY SHAFT ALLOWING FOREIGN MATERIAL TO SPLIT THE O-RING. PILOT WAS ADVISED TO MAKE SURE SHAFTS ARE KEPT CLEAN. (S)

WHILE FLYING A FIRE MISSION IN SUPPORT OF USFS, THE PILOT NOTICED THE RT ENG OIL PRESSURE FLOWLY STARTING TO DECREASE. THE DECISION WAS MADE TO RETURN TO THE AIRPORT. AS OIL PRESSURE CONTINUED TO DECREASE, THE DECISION WAS MADE TO SHUTDOWN, FEATHER, AND SECURE THE ENG. A SAFE LANDING WAS ACCOMPLISHED AND THE ACFT WAS TAKEN OUT OF SERVICE. UPON INSPECTION, IT WAS FOUND THAT THE NR 3 CYLINDER`S PISTON RINGS AND RING GROOVES WERE DAMAGED, WHICH PRESSURIZED THE CASE AND PUMPED THE ENG OIL OVERBOARD. THE ENG WAS REMOVED AND SENT FOR OVERHAUL AS A PRECAUTION. PROBABLE CAUSE: POSSIBLE BROKEN RING OR POSSIBLE DETONATION. (S)

TIRE DEVELOPED SEVERE CORD SEPARATION, PRODUCED A BUBBLE ON OUTSIDE OF TIRE, AND HAD AIR BETWEEN THE PLYS.

INSPECTION FOUND CORD SEPARATION OCCURRING IN TIRE.

RIGHT GEAR FAILED. TROUBLESHOOTING FOUND ALL COMPONENTS OPERATIONAL. HIGH RESISTANCE FOUND FROM PIN 33 ON RELAY PANEL A123 AND PIN B AT GCU. CAUSE FOUND IN WIRE P41R16 WITHIN THE BUNDLE RUNNING FROM RELAY PANEL A123 WHERE WIRE HAD BEEN STAMPED BY LABELING MACHINE CAUSING AN INDENTATION IN SHIELDED WIRE WHICH APPARENTLY ALLOWED ARCING TO OCCUR AND EVENTUALLY BURNED THROUGH THE CONDUCTOR. WIRE WAS SPLICED AND SYSTEM OPERATED NORMALLY.

RT ENGINE FUEL PRESSURE SWITCH FAILED IN OPEN POSITION. TT: 2,193.9 HRS. SUBMITTER STATED THIS IS THE 2ND SWITCH TO FAIL IN FLEET.

DURING C/W TWIN COMMANDER SB NR 195B, FOUND BOTH AFT RUDDER CABLES TO HAVE NUMEROUS CABLE STRANDS BROKEN. THE INSTRUCTIONS IN THE SB DO NOT ADDRESS THE REMOVAL OR INSPECTION AS OUTLINED IN AC 43.13-1A, CHAPTER 4, PARAGRAPH 198, FIGURE 4.14. THE SB PROCEDURE IS THE ONLY WAY TO PROPERLY INSPECT THESE CABLES. HAVE FOUND MANY AIRCRAFT WITH CABLE STRANDS BROKEN BEYOND THE LIMITS IN THE SB WHILE INSPECTING THE CABLES IN THIS MANNER. SUBMITTER SUGGESTS OWNERS C/W SI-199, WHICH INSTALLS LARGER PULLEYS AT THIS LOCATION.

DURING C/W TWIN COMMANDER SB NR 195B, FOUND BOTH AFT RUDDER CABLES TO HAVE NUMEROUS CABLE STRANDS BROKEN. THE INSTRUCTIONS IN THE SB DO NOT ADDRESS THE REMOVAL OR INSPECTION AS OUTLINED IN AC 43.13-1A, CHAPTER 4, PARAGRAPH 198, FIGURE 4.14. THE SB PROCEDURE IS THE ONLY WAY TO PROPERLY INSPECT THESE CABLES. HAVE FOUND MANY AIRCRAFT WITH CABLE STRANDS BROKEN BEYOND THE LIMITS IN THE SB WHILE INSPECTING THE CABLES IN THIS MANNER. SUBMITTER SUGGESTS OWNERS C/W SI-199, WHICH INSTALLS LARGER PULLEYS AT THIS LOCATION.