20090409005899A

(-23) ON APRIL 9, 1009, EXPERIMENTAL AMATEUR BUILT LIGHT SPORT MOTOR GLIDER, ZEALOT N61ZT, SUSTAINED SUBSTANTIAL DAMAGE DURING AN OFF-AIRPORT LANDING FOLLOWING A TOTAL LOSS OF POWER DUE TO ENGINE FAILURE. THE ^PRIVACY DATA OMITTED^PILOT IN COMMAND, WHO WAS THE SOLE OCCUPANT OF THE GLIDER, WAS NOT INJURED. ACCORDING TO THE PILOT, N61ZT WAS SELF LAUNCHED FROM GRASS ROOTS AIRPORT IN MASCOTTE, FLORIDA ON THE GLIDER’S FIRST FLIGHT AFTER BEING PURCHASED FROM THE ORIGINAL ^PRIVACY DATA OMITTED^BUILDER. AT AN ALTITUDE OF APPROXIMATELY 1,800 FEET, THE ENGINE OF N61ZT EXPERIENCED A TOTAL LOSS OF POWER AND DID NOT RESPOND TO RE-START ATTEMPTS. N61ZT WAS BEYOND GLIDING DISTANCE FROM A SUITABLE AIRPORT, WHICH RESULTED IN THE PILOT EXECUTING AN OFF AIRPORT LANDING IN A DRY LAKE BED. A POST ACCIDENT INSPECTION OF N61ZT, CONDUCTED BY FAA INSPECTORS ON 04-10-2009, REVEALED DAMAGE TO NUMEROUS PORTIONS OF THE AIRCRAFT, TO INCLUDE, BUT NOT LIMITED TO, THE PROPELLER, LANDING GEAR, CANOPY, STRUCTURAL COMPONENTS OF THE FUSELAGE, STRUCTURAL COMPONENTS OF THE LEFT AND RIGHT WINGS, AND STRUCTURAL COMPONENTS OF THE EMPENNAGE. A POST ACCIDENT DISASSEMBLY AND INSPECTION OF THE ROTAX 582 ENGINE INSTALLED IN N61ZT, OBSERVED BY FAA INSPECTORS ON 04-102009, REVEALED DESTRUCTION OF THE ROTARY VALVE DISC DRIVE GEAR DUE TO INSUFFICENT LUBRICATION. SUCH GEAR FAILURE CAUSED THE ROTARY VALVE SHAFT AND ATTACHED ROTARY VALVE DISC TO CEASE ROTATION, RESULTING IN ENGINE STOPPAGE DUE TO THE INABILITY OF THE ROTARY VALVE DISC TO INTRODUCE THE AIR/FUEL MIXTURE FROM THE CARBURETORS INTO THE INTAKE PORTION OF THE ENGINE’S CYLINDERS. INSUFFICIENT LUBRICATION OF THE ROTARY VALVE DISC DRIVE GEAR WAS DETERMINED DURING THE ENGINE DISASSEMBLY WHEN INSPECTORS OBSERVED APPROXIMATELY 2 FLUID OUNCES OF OIL DRAIN FROM THE ROTARY VALVE SHAFT “OIL BATH” CHAMBER WHEN THE SHAFT ASSEMBLY WAS REMOVED FROM THE ENGINE CASE. ACCORDING TO THE ROTAX INSTALLATION MANUAL, APPROXIMATELY 310CC (10.5 FLUID OUNCES) OF OIL IS REQUIRED TO FILL THE ROTARY VALVE SHAFT LUBRICATION SYSTEM. WITH ONLY 2 FLUID OUNCES OF OIL IN THE ROTARY VALVE SHAFT “OIL BATH” CHAMBER DURING ENGINE OPERATION, THE ROTARY VALVE DISC DRIVE GEAR WAS SUBJECTED TO SIGNIFICANT HEAT, CAUSING CATASTROPHIC FAILURE OF THE BRASS DRIVE GEAR DUE TO INSUFFICIENT LUBRICATION. HOWEVER, IT IS IMPORTANT TO NOTE THAT INSPECTION OF THE ENGINE COMPONENTS PRIOR TO REMOVAL AND DISASSEMBLY OF THE ENGINE FROM THE AIRFRAME OF N61ZT REVEALED THAT THE EXTERNALLY MOUNTED OIL TANK FOR THE ROTARY VALVE SHAFT LUBRICATION SYSTEM WAS FILLED TO THE PROPER LEVEL. HOWEVER, IT IS IMPORTANT TO NOTE THAT INSPECTION OF THE ENGINE COMPONENTS PRIOR TO REMOVAL AND DISASSEMBLY OF THE ENGINE FROM THE AIRFRAME OF N61ZT REVEALED THAT THE EXTERNALLY MOUNTED OIL TANK FOR THE ROTARY VALVE SHAFT LUBRICATION SYSTEM WAS FILLED TO THE PROPER LEVEL. INFORMATION OBTAINED FROM THE ROTAX INSTALLATION MANUAL AND FROM ROTAX SERVICE CENTER TECHNICIANS HAS SUBSTANTIATED THAT IT IS POSSIBLE FOR THE ROTARY VALVE SHAFT LUBRICATION SYSTEM EXTERNALLY MOUNTED OIL TANK TO CONTAIN A FULL QUANTITY OF OIL WITHOUT THE ROTARY VALVE SHAFT “OIL BATH” CHAMBER WITHIN THE ENGINE CASE ACTUALLY BEING FULL OF OIL. THIS PHENOMENON CAN OCCUR IN ROTAX 582 ENGINES MOUNTED ON AN AIRFRAME IN THE INVERTED POSITION (SPARK PLUGS DOWN) IF ROTARY VALVE SHAFT OIL IS INSTALLED WITHOUT REMOVING A VENT PLUG IN THE ENGINE CASE TO VENT THE SYSTEM DURING OIL INSTALLATION. WITHOUT REMOVAL OF THE VENT PLUG, AN “AIR BUBBLE” CAN FORM IN THE ROTARY VALVE SHAFT “OIL BATH” CHAMBER, THUS PREVENTING OIL FROM FILLING THE CHAMBER. IF THIS OCCURS, THE OIL TANK WILL INDICATE FULL, BUT INSUFFICIENT OIL WILL HAVE BEEN INTRODUCED INTO THE ROTARY VALVE SHAFT “OIL BATH” CHAMBER, THUS CAUSING FAILURE OF THE ROTARY VALVE SHAFT BRASS DRIVE GEAR DURING ENGINE OPERATION. THE ENGINE IN N61ZT WAS MOUNTED IN THE INVERTED POSITION, AND SUCH ENGINE WAS REINSTALLED ONTO THE AIRFRAME OF N61ZT BY THE ORIGINAL ^PRIVACY DATA OMITTED^BUILDER ON AUGUST 7, 2008, FOLLOWING ENGINE OVERHAUL. THE ORIGINAL ^PRIVACY DATA OMITTED^BUILDER STATED TO THE FAA IIC THAT HE INSTALLED THE ROTARY VALVE SHAFT OIL FOLLOWING REINSTALLATION OF THE ENGINE ONTO THE AIRFRAME OF N61ZT. UPON FURTHER QUESTIONING BY THE FAA IIC, THE ORIGINAL OWNER/BUILDER ACKNOWLEDGED THAT HE DID NOT REMOVE THE VENT PLUG DURING OIL INSTALLATION. ACCORDINGLY THE ENGINE FAILURE ASSOCIATED WITH THE ACCIDENT OF N61ZT IS DETERMINED TO BE A FAILURE OF THE ROTARY VALVE DIS DRIVE GEAR DUE TO INSUFFICIENT LUBRICATION CAUSE BY IMPROPER INSTALLATION OF ROTARY VALVE SHAFT OIL. ALTHOUGH NOT DIRECTLY RELATED TO THE CAUSE OF THE ACCIDENT OF N61ZT, ADDITIONAL INFORMATION ASSOCIATED WITH VIOLATION OF FAA REGULATIONS WAS DISCOVERED DURING THE INVESTIGATION. PILOT IN COMMAND ^PRIVACY DATA OMITTED^, HOLDER OF PRIVATE PILOT CERTIFICATE NUMBER ^PRIVACY DATA OMITTED^, OPERATED N61ZT ON APRIL 9, 2009 WITHOUT BEING IN POSSESSION OF OPERATING LIMITATIONS FOR THE EXPERIMENTAL AIRCRAFT. ADDITIONALLY, ^PRIVACY DATA OMITTED^ OPERATED N61ZT ON APRIL 9, 2009 WITHOUT PREVIOUSLY RECEIVING GROUND AND FLIGHT TRAINING ON GLIDER SELF LAUNCH PROCEDURES AND OPERATIONS, TO INCLUDE THE ASSOCIATED LOGBOOK ENDORSEMENT FROM AN AUTHORIZED INSTRUCTOR, AS REQUIRED FOR THE OPERATION OF A MOTOR GLIDER IN ACCORDANCE WITH 14 CFR PART 61.31 (J)(III). APPROPRIATE ENFORCEMENT ACTION WILL BE TAKEN AGAINST ^PRIVACY DATA OMITTED^ REGARDING THE ISSUES DESCRIBED HEREIN. ^PRIVACY DATA OMITTED^, HOLDER OF LIGHT SPORT AIRCRAFT REPAIRMAN CERTIFICATE NUMBER ^PRIVACY DATA OMITTED^, CONDUCTED A CONDITION INSPECTION FOR N61ZT ON MARCH 25, 2009 WITHOUT GLIDER INSPECTION PRIVILEGES INCLUDED ON HIS REPAIRMAN CERTIFICATE. APPROPRIATE ENFORCEMENT ACTION WILL BE TAKEN AGAINST ^PRIVACY DATA OMITTED^ REGARDING THIS ISSUE.