A PA44 PIPER SEMINOLE HAS NOSE GEAR COLLAPSE ON LNDG.

Narrative

MY STUDENT AND I PLANNED A TRAINING FLT. THE PURPOSE OF THE FLT WAS A REVIEW OF ALL MULTI ENG MANEUVERS PRIOR TO HIS MEI CHK RIDE. WE WERE DISPATCHED THE ACFT AND PROMPTLY COMPLETED A THOROUGH PREFLT INSPECTION IN WHICH NO PROBS WERE NOTED. THE NOSE GEAR WAS INSPECTED AND NO DEFICIENCIES WERE DETECTED AT THIS TIME. WE DEPARTED FROM DAB AND CLBED UP TO 5500 FT IN ORDER TO PERFORM ALL HIGH ALT MANEUVERS. UPON COMPLETION OF THOSE MANEUVERS WE DSNDED TO 800 FT; 1 MI S OF NEW SMYRNA ARPT (EVB) AND ENTERED THE TFC PATTERN FOR RWY 24. THE LNDG GEAR WAS EXTENDED MIDFIELD DOWNWIND AND THE INDICATORS VISUALLY VERIFIED AS 3 GREEN LIGHTS. WE TURNED BASE AND FINAL; EACH TIME CHKING THE GEAR INDICATORS. NO PROBS WERE FOUND AND A NORMAL LNDG WAS EXECUTED. WE APPLIED FULL PWR AND PROCEEDED WITH ANOTHER TFC PATTERN AND LNDG. AGAIN; THE GEAR WAS EXTENDED ON DOWNWIND; THE GEAR INDICATORS CHKED 3 TIMES; AND THE NOSE GEAR VISUALLY VERIFIED DOWN BY WAY OF THE MIRROR ON THE L ENG. AN EXCEPTIONALLY SOFT LNDG WAS MADE ON THE MAIN WHEELS AND THE NOSEWHEEL TOUCHED THE RWY A SECOND LATER. IT HELD FOR 1 SECOND AND THEN IT COLLAPSED BACK INTO THE WHEEL WELL. AS SOON AS I DETECTED THE NOSE SCRAPING ON THE RWY AND THE PROPS STRIKING THE GND; I SHUT OFF ALL SWITCHES AND CUT THE MIXTURES. THE ACFT SLID FOR APPROX 500 FT. AFTER IT STOPPED; WE SAFELY EXITED THE ACFT AND CALLED OUR FLT SCHOOL. UPON INSPECTION OF THE NOSE GEAR BY AN A&P MECH; A BOLT WAS DISCOVERED SHEARED IN HALF. THE BOLT HELPED TO KEEP THE NOSE GEAR IN THE DOWN AND LOCKED POS AND ITS LOSS ALLOWED THE GEAR TO FOLD BACK IN SPITE OF THE HYD PRESSURE IN THE SYS. I HAVE BEEN FLYING PIPER SEMINOLES AT THIS FLT SCHOOL FOR OVER 5 YRS NOW AND I HAVE NEVER HAD A PROB LIKE THIS. ALL THE PROPER MAINT HAD BEEN COMPLETED AND A PROPER PREFLT INSPECTION HAD BEEN PERFORMED. THE BOLT IN QUESTION SEEMED INTACT AT THAT TIME AND THE SHEAR WAS NOT VISIBLE DURING THE PREFLT. THERE DOES NOT SEEM TO BE A DEFINITE WAY OF PREVENTING THIS PARTICULAR OCCURRENCE. IN THE FUTURE; I WILL BE INSPECTING THE HARDWARE IN THE LNDG GEAR CLOSER TO SEE IF I AM ABLE TO DETECT A PROB PRIOR TO FAILURE OF THE GEAR. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES THERE WAS NO ENG DAMAGE; THE INSURANCE COMPANY MADE THEM TEAR DOWN THE ENGS TO BE ASSURED OF THAT. RPTR SPOKE TO MECH AND WAS TOLD IT WAS THE MIDDLE NOSE GEAR DRAG LINK BOLT THAT HAD FAILED. THIS IS A VERY RARE OCCURRENCE.