20030705021229A

(-23) ON JULY 05, 2003, I ARRIVED AT THE AIRCRAFT ACCIDENT SCENE WHERE N216ST, A MCILRATH SEA RAY, SERIAL #1MK216, HAD CRASHED NEXT TO COUNTY ROAD T APPROXIMATELY A MILE SOUTH OF INTERSTATE 90/94 OUTSIDE OF TOMA, WISCONSIN, IN MONROE COUNTY. THE AIRCRAFT HAD CRASHED AT APPROXIMATELY 0912 HOURS AS WAS INDICATED BY THE OCCUPANTS' WATCHES AND EYE WITNESS ACCOUNTS. THE AIRCRAFT WAS AN EXPERIMENTAL BUILT AMPHIBIAN AIRCRAFT BUILT BY THE OCCUPANTS AND POWERED BY A ROTAX, MODEL 914-ENGINE EQUIPPED WITH A VARIABLE PITCH PROPELLER, IVO MODEL 70GA. THE AIRCRAFT AND NAME BECAME INSTANTLY RECOGNIZABLE WHEN I APPROACHED THE AIRCRAFT BECAUSE OF AN ACCIDENT INVESTIGATION I HAD CONDUCTED IN 2001 AT THE LACROSSE, WI, AIRPORT INVOLVING THE AIRCRAFT AND MR. TERRY MCILRATH THE APPARENT OCCUPANT. THE AIRCRAFT HAD DUAL CONTROLS, AND IT IS NOT KNOWN FOR CERTAIN WHO THE PILOT-IN-COMMAND WAS. I AM ASSUMING THAT THE INDIVIDUALS WERE IN THE APPROPRIATE SEATS, THUS MR. STUART MERTON MCILRATH WOULD HAVE BEEN THE PILOT. THE ACCIDENT SCENE WAS INSTANTLY RECOGNIZABLE AS A STALL SPIN. WRECKAGE WAS GROUPED IN A TIGHT PATTERN WITH THE TAIL POINTING UP AND KINKED OVER TO WEST. FLIGHT INSTRUMENTS INDICATED THAT THE AIRCRAFT HAD IMPACTED THE EARTH INVERTED AND IN A LEFT WING LOW AND A 30 DEGREES OR MORE NOSE DOWN PITCH ATTITUDE (THIS IS CONSISTENT WITH EYE WITNESS ACCOUNTS). IT WAS REPORTED THAT THE AIRCRAFT PITCHED UP AND THEN DOVE TO THE GROUND WHILE TURNING 1-1/2 TIMES BEFORE IMPACTING THE EARTH. I WAS NOT ABLE TO ASCERTAIN THE AIRSPEED. THE MANIFOLD PRESSURE GAUGE READ 31 INCHES OF MANIFOLD PRESSURE. THERE WAS EVIDENCE OF A SIGNIFICANT FUEL SPILL INDICATING THAT ADEQUATE FUEL WAS ON BOARD THE AIRCRAFT. AIRCRAFT DAMAGE WAS SO SEVERE IT WAS DIFFICULT TO DETERMINE IF THE ENGINE WAS DEVELOPING POWER AT THE TIME OF IMPACT. ALL OF THE PROPELLER BLADES WERE BROKEN OFF APPROXIMATELY 11 INCHES OUT FROM THE HUB AND DID NOT SHOW SIGNS OF IMPACT; HOWEVER, ONE BLADE WAS LOCATED APPROXIMATELY 150 FEET FROM THE ACCIDENT SCENE NORTH AND EAST OF THE ACCIDENT SITE ON THE OTHER SIDE OF THE ROAD. THERE WAS CONTINUITY WITH THE CONTROLS AND THE CONTROL SURFACES. THE WEATHER ON JULY 5, 2003, AT TOMA, WISCONSIN, AT 0912 HOURS WAS CLEAR WITH UNRESTRICTED VISIBILITY AND CALM WINDS. BOTH BODIES WERE SENT FOR AUTOPSY, AND IT IS THE OPINION OF THE ATTENDING PHYSICIAN THAT HEART ATTACK AND STROKE FOR BOTH OCCUPANTS WAS NOT LIKELY A CAUSAL FACTOR. THERE WERE POWER LINES CLOSER TO THE ACCIDENT SITE TO THE WEST PARALLELING THE ROAD. THE DISCOVERY OF A 1/4-INCH TEAR IN THE FUEL PRESSURE REGULATOR (AS REPORTED BY INSPECTOR DERNER) COULD HAVE CAUSED THE ENGINE TO FAIL. IT IS PROBABLE THAT THE PILOT PREPARED FOR AN EMERGENCY LANDING AND DISCOVERED THE POWER LINES. ^PRIVACY DATA OMITTED^ ROBERT K. GESSERT AIRCRAFT PROGRAM MANAGER. INSPECTORS STATEMENT: AIRCRAFT - MCILRAITH SEAREY S/N 1MK216; ENGINE - ROTAX 914 S/N 4417850; PROPELLER - WARP DRIVE 3 BLADE ELECTRIC CONTROLLABLE PITCH; EXAMINATION OF THE ACCIDENT SITE REVEALED THE AIRCRAFT IMPACTED THE GROUND AT A STEEP NOSE DOWN ANGLE. THERE WAS EVIDENCE OF SUBSTANTIAL FUEL SPILLAGE DUE TO THE MAIN FUEL TANK SPLITTING AT THE SEAM DURING IMPACT. TWO PROPELLER BLADES WERE RECOVERED ONE OF WHICH WAS FOUND APPROXIMATELY 150 FEET FORWARD OF THE WRECKAGE. EXAMINATION OF THE PROP BLADES INDICATED NO IMPACT DAMAGE ON THE LEADING EDGE. CONTINUITY OF ALL FLIGHT CONTROLS WAS ESTABLISHED. THE ROTA X ENGINE ROTATED FREELY, HAD COMPRESSION ON ALL FOUR CYLINDERS, AND CONTINUITY OF THE VALVE TRAIN SYSTEM WAS PROVEN. THE SPARK PLUGS AND THE INSIDE OF THE INTAKE MANIFOLDS WERE DRY. THE FLOAT CHAMBERS OF BOTH CARBURETORS WERE DRY AND HAD NOT EVIDENCE OF RESIDUAL FUEL. THE DIAPHRAGM TYPE FUEL PRESSURE REGULATOR THAT DIRECTLY FEEDS BOTH CARBURETORS WAS DISASSEMBLED AND DID NOT CONTAIN ANY RESIDUAL FUEL. INSPECTION OF THE FUEL PRESSURE REGULATOR DIAPHRAGM REVEALED A ONE-QUARTER INCH SQUARE TEAR NEAR THE CENTER WHERE THE SPRING SEATS ON THE DIAPHRAGM. THE TURBO CHARGER WAS EXAMINED AND ROTATED FREELY. TIM DERNER PRINCIPAL MAINTENANCE INSPECTOR MILWAUKEE FSDO.