N407AL

Part: BEARING — SEPARATED (MAIN ROTOR) · airframe 11,970 hrs

SHEAR ELASTOMERIC BEARING SEPARATING.

Part: FLOOR PANEL — DELAMINATED (ZONE 100) · airframe 11,420 hrs

FLOOR DELAMINATION REQUIRING MAJOR REPAIR.

Part: FRAME — CRACKED (BS 231.5) · airframe 11,420 hrs · 9,820 cycles

1.5 INCH CRACK IN THE FRAME AT STATION 231.5.

Part: SHAFT — CRACKED (TURBINE SECTION) · airframe 10,277 hrs

ENGINE HAD HIGH OIL CONSUMPTION. DISASSEMBLED PT SECTION OF TURBINE AND DISASSEMBLED PT ROTOR. FOUND EXCESSIVE AMOUNT OF OIL BETWEEN PT INNER AND PT OUTER SHAFTS. CLEANED OFF PARTS AND INSPECTED. DISCOVERED CRACK IN INNER SHAFT BELOW INNER NUT THREADS WHICH CAUSED LACK OF TORQUE OF PT ROTOR ALLOWING OIL TO PASS THROUGH 9-11/13-18 SEAL GOING THRU INNER SHAFT AND ROTOR. NOTE: CRACK WAS APPROX .2500 OF THE DIAMETER AROUND THE INNER SHAFT AND THROUGH WALL TO INSIDE DIAMETER OF SHAFT.

Part: BLADE — CRACKED (TAIL ROTOR)

DURING DAILY INSPECTION, BLADE CRACKED AT WEEP HOLE, ON THE INBOARD LEADING EDGE. CRACK EXTENDED AFT FOR ABOUT 1.50 INCHES. (X)

Part: BEARING — WORN (TAIL ROTOR)

DURING DAILY INPSECTION FOUND BEARINGS WORN, AXIAL PLAY.

Part: BEARING — WORN (TAIL ROTOR)

DURING DAILY INPSECTION FOUND BEARINGS WORN, AXIAL PLAY.

Part: BEARING — ROUGH (TAIL ROTOR)

DURING DAILY INSPECTION BOTH BEARINGS FOUND ROUGH.

Part: BEARING — ROUGH (TAIL ROTOR)

DURING DAILY INSPECTION BOTH BEARINGS FOUND ROUGH.

Part: CASE — WORN (T/R GEARBOX)

PRE-FLIGHT INSPECTION FOUND MOUNTING PADS WORN BEYOND LIMITS IN BHT 407 CR&O MANUAL. ONE EACH DOW ALIGNMENT PIN BROKEN. FURTHER TEAR-DOWN REVEALED HIGH GEAR BACKLASH AND SCARING OF THE GEAR TEETH. POSSIBLY DUE TO LOW OR ABSENCE OF OIL AT THE SAME TIME. HIGH VIBRATION CAUSED GEARBOX TO LOOSEN UP.

Part: BEARING — ROUGH (TAIL ROTOR)

FOUND HOUSING, 206-061-432-116, CRACKED AND WORKING RIVETS. FOUND 2 EACH BEARINGS, 407-340-339-103, ROUGH. TT 146.8 HOURS. FOUND SHAFT 407-040-320-101 SPLINES WORN. TT 1,234.4 HOURS.

Part: HOUSING — CRACKED (TAIL ROTOR)

FOUND HOUSING, 206-061-432-116, CRACKED AND WORKING RIVETS. FOUND 2 EACH BEARINGS, 407-340-339-103, ROUGH. TT 146.8 HOURS. FOUND SHAFT 407-040-320-101 SPLINES WORN. TT 1,234.4 HOURS.

Part: DISC PACK — CRACKED (T/R DRIVE)

DURING COMPLIANCE OF AD 97-24-17 PTA, FOUND NR 6 D/S DISC PACK CRACKED. TWO DISC VISUALLY CRACKED APPROXIMATELY MID-WAY BETWEEN TWO BOLT HOLES.

Part: DISK PACK — CRACKED (T/R DRIVE)

DURING 25 HOUR AD, INSPECTED ALL COUPLINGS, FOUND NR 6 COUPLING CRACKED.

Part: HORN — CORRODED (M/R HUB)

AT 2,500 HOUR OVERHAUL OF M/R HUB, DISCOVERED 1 EACH PITCH HORN CORRODED BEYOND LIMITS UNDER PLATE, 3 EACH PITCH HORNS CORRODED BEYOND LIMITS IN DOWEL PIN BORE.

Part: HORN — CORRODED (M/R HUB)

AT 2,500 HOUR OVERHAUL OF M/R HUB, DISCOVERED 1 EACH PITCH HORN CORRODED BEYOND LIMITS UNDER PLATE, 3 EACH PITCH HORNS CORRODED BEYOND LIMITS IN DOWEL PIN BORE.

Part: HORN — CORRODED (M/R HUB)

AT 2,500 HOUR OVERHAUL OF M/R HUB, DISCOVERED 1 EACH PITCH HORN CORRODED BEYOND LIMITS UNDER PLATE, 3 EACH PITCH HORNS CORRODED BEYOND LIMITS IN DOWEL PIN BORE.

Part: HORN — CORRODED (M/R HUB)

AT 2,500 HOUR OVERHAUL OF M/R HUB, DISCOVERED 1 EACH PITCH HORN CORRODED BEYOND LIMITS UNDER PLATE, 3 EACH PITCH HORNS CORRODED BEYOND LIMITS IN DOWEL PIN BORE.

Part: INSERTS — LOOSE (GEARBOX)

UPON VISUAL INSPECTION OF PARTS, FOUND 1 EACH INSERT PULLED OUT OF GEARBOX HOUSING AND 2 EACH INSERTS LOOSE AT EXCITER BOX MATING SURFACE. ONE EACH INSERT P/N NAS1394-3L WAS PULLED OUT AND 2 EACH INSERTS WERE FOUND LOOSE. POSSIBLE CAUSE IS EXCESSIVE CLEARANCE BETWEEN BOX AND HOUSING CAUSING BOX TO GET HUNG UP OR HIT ON ENGINE REMOVAL.

Part: BEARING — GALLED (NR 5)

ENGINE WAS REMOVED FOR MAKING METAL. INSPECTED AND FOUND GALLING ON NR 5 BEARING AND METAL SLIVERS UNDER NR 5 BEARING NUT AND CUP WASHER. ALSO FOUND NR 5 BEARING INTERNAL OUTER RACE DETERIORATING.

Part: SUPPORT — MISSING (LT HORIZ STAB)

DURING POST-FLIGHT INSPECTION, THE SPOILER TO THE LT SIDE OF THE HORIZONTAL STABILIZER WAS FOUND MISSING AND HAD STRUCK ONE TAIL ROTOR BLADE CAUSING MINOR DAMAGE. THERE WAS NO FEED BACK IN THE CONTROLS DURING FLIGHT THAT WOULD HAVE WARNED OF ANY IMPACT TO THE TAIL ROTOR. REMAINING PORTIONS OF SUPPORTS SHOW EVIDENCE OF FATIGUE CRACKS. THE REMAINING PORTIONS OF SUPPORTS SHOW EVIDENCE OF FATIGUE CRACKS. THE REMAINING PIECES ARE BEING SENT TO BELL FOR EVALUATION. FLEET HAS BEEN CHECKED, AND TWO MORE SLATS HAVE BEEN FOUND WITH CRACKS.

Part: SKIN — DAMAGED (VERTICAL FIN)

DEFECT WAS DISCOVERED DURING INSPECTION ASB 407-98-17. FOUND CUTS IN SKIN ON FORWARD AND AFT SIDES OF AFT LOWER INSERT AT ENDS OF FORMERS FOR COWLING. THE CAUSE IS THE SKIN WAS CUT DURING TRIMMING OF THE FORMERS DURING PRODUCTION. COMPONENT P/N 206020113323A.

Part: BEARING — WORN (T/R DRIVE HANGER)

SCHEDULED MAINTENANCE FOUND TAIL ROTOR DRIVESHAFT NR 2 HANGER BEARING ROUGH AND WORN, AXIAL PLAY.

Part: BOLT — WORN (T/R DRV SUPPORT)

SCHEDULED MAINTENANCE FOUND TAIL ROTOR DRIVESHAFT NR 2 BOLT WORN OR STEPPED, FRETTING.

Part: BRACKET — WORN (T/R DRIVESHAFT)

SCHEDULED MAINTENANCE FOUND NR 2 TAIL ROTOR DRIVESHAFT FORWARD BRACKET UPPER BOLT HOLE WORN ELLIPTICAL.

Part: DISK PACK — CRACKED (T/R DRIVE)

IN C/W AD 97-24-17 DURING PHASE 6, FOUND ONE CRACKED LAMINATE OF TAIL ROTOR DRIVESHAFT DISK PACK AT NR 7 HYDRAULIC FORWARD LAMINATE.

Part: BLADE — CRACKED (T/R)

DAILY INSPECTION FOUND CRACK AT ROOT END OF T/R BLADE ON THE INSIDE OF THE LEADING EDGE. SUSPECT CAUSE IS HIGH STRESS AREA. PART IS UNSERVICEABLE. INSTALLED BEEF-UP STRESS BLOCK IN LEADING EDGE AT ROOT END OF BLADE.

Part: DISC PACK — CRACKED (T/R DRIVE)

WHILE C/W AD 97-22-15, FOUND T/R DRIVE DISC PACK CRACKED BETWEEN NR 6 AND NR 7. SUBMITTER RECOMMENDS FLOATING DRIVESHAFTS SIMILAR TO THE BELL 206 SERIES.

Part: COUPLING — CRACKED (T/R D/S COUPLING)

DAILY INSPECTION FOUND NR 7 TAIL ROTOR DRIVESHAFT COUPLING, NR 10 DISC ON PACK CRACKED.

Part: DISC PACK — CRACKED (T/R DRIVE)

DAILY INSPECTION IAW MAINTENANCE NOTAM 51A-97, NR 3 DRIVE SHAFT, FOUND 3RD DISC IN PACK WAS CRACKED.

Part: DISC PACK — CRACKED (NR 6 T/R D/S)

DURING DAILY INSPECTION IAW MAINTENANCE NOTAM 51A-97, FOUND NR 6 TAIL ROTOR DRIVESHAFT, NR 1 DISC IN PACK CRACKED.

Part: DISC — CRACKED (T/R DRIVE)

DAILY INSPECTION AND C/W NOTAM NR 51A-97, FOUND DISC CRACKED. ON NR 7 DISC ASSEMBLY, NR 7 DISC OF THE PACK - 1 DISC ONLY.

Part: DISC — CRACKED (NR 7 T/R SHAFT)

DURING MAINTENANCE NOTAM 51A-97 INSPECTION, FOUND LAMINATE CRACKED ON NR 7 TAIL ROTOR DRIVESHAFT COUPLING DISC.

Part: COUPLING DISK — CRACKED (NR 6/7 T/R DRIVE)

INSPECTION FOUND NR 6 AND NR 7 EACH HAS ONE LAMINATE DISC CRACKED.

Part: COUPLING DISK — CRACKED (NR 7 T/R DRIVE)

DURING 50-HOUR PMI, FOUND NR 7 TAIL ROTOR DRIVESHAFT HAD 1 LAMINATE CRACKED.

Part: FRAHM DAMPER — DAMAGED (MAIN ROTOR HUB)

PILOT REPORTED A ONE-TO-ONE VIBRATION. WHILE WORKING ON THE ROTOR VIBRATION, THE FRAHM DAMPER WAS FOUND DAMAGED. UPON REMOVING MAIN ROTOR COVER ASSEMBLY, NOTED ITEM 32 (LINER ASSEMBLY) HAD EXCESSIVE CONTACT WITH ITEM 17 (PAD ASSEMBLY). LINER ASSEMBLY WAS BROKEN INTO NUMEROUS PIECES. PAD ASSEMBLY WAS ALSO EXCESSIVELY DAMAGED. THE UPPER FLANGES ON ITEM 18 (WEIGHT ASSEMBLY) CONTACTED THE RADIUS AREA OF ITEM 34 (HOUSING ASSEMBLY) TO A POINT WHICH CAUSED THE HOUSING ASSEMBLY TO BE GOUGED AND CRACKED IN THE RADIUS AREA.

Part: DISC PACK — CRACKED (T/R DRIVE)

DURING A 50-HOUR PREVENTIVE MAINTENANCE INSPECTION, FOUND DISC PACK CRACKED.

Part: DISC PACK — CRACKED (T/R DRIVE)

DURING 50-HOUR PREVENTIVE MAINTENANCE INSPECTION, FOUND T/R DRIVE SHAFT DISC PACK CRACKED.

Part: DISC PACK — CRACKED (T/R SHAFT)

DURING ROUTINE INSPECTION, FOUND ONE DISC OF DISC PAC CRACKED IN THREE PLACES. TWO CRACKS WERE RUNNING PARALLEL WITH THE GRAIN METAL EXTENDING APPROXIMATELY 75 PERCENT OF THE WIDTH OF THE DISC. THE THIRD CRACK RUNNING PERPENDICULAR TO THE GRAIN APPROXIMATELY 75 PERCENT OF THE WIDTH OF THE DISC.

Part: DISC PACK — CRACKED (NR 6 T/R SHAFT)

DURING A 50-HOUR INSPECTION, FOUND T/R COUPLING DISC PACK, P/N 406-090-340-101, TO HAVE A CRACK ON ONE OUTER LAMINATE EXTENDING THREE-FOURTHS OF THE WAY THROUGH THE LAMINATE. THE DESIGN OF THIS AIRCRAFT DOES NOT ALLOW THE NR 4 THROUGH THE NR 7 (ALL OF THEM ON THE TAILBOOM) T/R DRIVESHAFTS TO FLOAT. IT IS GOING TO BE HARDER ON DISC PACS THAN A 206L. THIS IS THE THIRD OCCURRENCE OF THIS PROBLEM ON A FLEET OF TWO A/C WITH 550 HOURS FLIGHT TIME COMBINED.

Part: CENTER CONE SET — DAMAGED (M/R)

AFTER SITTING OFFSHORE IN MODERATE WINDS, THE PILOT NOTICED AN INCREASE IN VIBRATION LEVEL OF THE MAIN ROTOR ON THE NEXT FLIGHT. THE MAIN ROTOR CENTER CONE SET P/N 407-010-111-101 HAS A THICK TEFLON COATING ON THE INSIDE OF CONES. THIS COATING WAS DAMAGED ALLOWING THE HUB TO SHIFT. NOTE: BEFORE THE MAIN ROTOR HEAD WAS REMOVED, A MAST NUT RE-TORQUE WAS PERFORMED. NO LOSS OF TORQUE WAS FOUND.

Part: HANGER SUPPORT — LOOSE (NR 4 T/R BRG)

DURING A 50-HOUR INSPECTION, THE NR 4 T/R BEARING HANGER SUPPORT WAS FOUND LOOSE FLOATING UP AND DOWN ON THE ATTACH BOLT. NR 7 HANGER SUPPORT WAS FOUND TO BE MAKING MUD AT CONTACT AREA WITH TAILBOOM BRACKET. FOUND ATTACH BOLT P/N NAS6604D65 WORN AND STEPPED ON NR 4 SHAFT AND ONLY SLIGHTLY WORN ON NR 7 SHAFT. THE 407 MM REQUIRES TORQUE OF 50-70 INCHES/POUNDS. NEITHER CHAPTER 65 OR PARAGRAPHS 1-13 TORQUES STATE WHETHER OR NOT NUT DRAG SHOULD BE FACTORED IN. ALSO, DRAWING IN THE TAILBOOM BRACKET WILL EFFECT THE FINAL TORQUE.

Part: BLADE — PAINT FLAKE (M/R)

PAINT FLAKING OFF LEADING EDGE AT TIP.

Part: BLADE — PAINT FLAKE (M/R)

PAINT FLAKING OFF LEADING EDGE AT TIP.