N177AL

Part: BLADE — DAMAGED (TAIL ROTOR) · airframe 16,190 hrs

TAIL ROTOR BLADE WAS FOUND TO HAVE HOLE IN TIP END OF BLADE.

Part: SERVO — DEFECTIVE (HYD SYSTEM) · airframe 16,012 hrs · 48,501 cycles

THE CYCLIC MADE AN AFT AND RT MOVEMENT WHEN THE HYD SYS SWITCH WAS MOVED FROM THE 'OFF' POSITION TO THE 'ON' POSITION, FOLLOWING THE DEMONSTRATION OF AN IN-FLIGHT HYD FAILURE AND HYDRAULICS OFF LANDING. WHILE STILL LANDED, THE INSTRUCTOR MOVED THE HYDRAULICS SYS SWITCH FROM 'ON' TO 'OFF' AND BACK TO 'ON'. THE CYCLIC MADE A SECOND AFT AND RT MOVEMENT. THE ACFT WAS SHUTDOWN AND MX WAS NOTIFIED. THIS MALFUNCTION OCCURRED DURING A TRAINING FLIGHT FOLLOWING 3 PREVIOUS LANDINGS WITH THE HYDRAULICS IN THE 'ON' POSITION.

Part: BLADE — CORRODED (ZONE 200) · airframe 15,581 hrs

SCRAPPED BLADE DUE TO DEBONDED DOUBLER AND CORROSION.

Part: STRIKER — OUT OF ADJUST (PILOT DOOR)

AT A HOVER, PILOTS DOOR WILL NOT STAY CLOSED, RETURNED TO LANDING PAD. MAINTENANCE ADJUSTED PILOTS DOOR AND STRIKER PLATES IAW THE MM. NO FURTHER DISCREPANCIES NOTED.

Part: BLADE — DEFECTIVE (MAIN ROTOR) · airframe 9,515 hrs

LOWER SURFACE GRIP FINGERS FOUND DEBONDED AT STA.38 - 43.5. DAMAGE APPEARS TO BE MANUFACTURING DEFECT. BLADE ASSY. WAS SENT TO BELL HELICOPTERS FORTWORTH. CUSTOMER PROPERTY RETURN.

Part: BLADE — DEBONDED (MAIN ROTOR)

DISCOVERED DURING ROUTINE AIRFRAME INSPECTION. SPAR LEADING EDGE EXFOLIATED ALONG ENTIRE LENGTH OF BLADE, SKIN/SPAR DISBOND AT LOWER SURFACE STA 58.5, CAUSED BY IMPROPER HEAT TREATING. REVIEW MANUFACTURING PROCESS AND IMPROVE QUALITY CONTROL.

Part: BLADE — DEBONDED (MAIN ROTOR)

DISCOVERED DURING ROUTINE AIRFRAME INSPECTION. SPAR LEADING EDGE EXFOLIATED ALONG ENTIRE LENGTH OF BLADE, SKIN/SPAR DISBOND AT LOWER SURFACE STA 58.5. CAUSED BY IMPROPER HEAT TREATING. C/A: REVIEW MANUFACTURING PROCESS AND IMPROVE QC.

Part: INDICATOR — STUCK (TOT)

AT INITIAL START, TOT INDICATOR STOP ARM STICKING TO LATEX BUMPER. REPLACE BUMPER WITH A DIFFERENT MATERIAL.

Part: SCAVENGE TUBE — CHAFED (NR 1 BEARING)

UPON DISASSEMBLY OF ENGINE FOR T/C, FOUND SCAVENGE TUBE HAD EXCESSIVE CHAFING FROM CONTACT WITH COMPRESSOR SCROLL. EXCESSIVE CHAFING ON TUBE DUE TO MISALIGNMENT CAUSING CONTACT WITH SCROLL. SUBMITTER STATED ENSURE PROPER CLEARANCE BETWEEN NR 1 SCAVENGE TUBE AND SCROLL AFTER INSTALLATION.

Part: LEVER ASSY — WORN (PYLON)

DAILY INSPECTION FOUND BUSHINGS AND BEARINGS WORN BEYOND LIMITS. PARTS REQUIRING REPLACEMENT: 4 EACH 206-010-338-001 SPACERS, 4 EACH 206-010-337-001 BEARINGS, 2 EACH 206-010-338-003 BUSHINGS, 2 EACH NAS6605D64 BOLTS, 1 EACH 206-010-470-101 BEARING. SUBMITTER STATED NORMAL USE CAUSED PARTS TO WEAR OUT TOO SOON. WORN PARTS TT 296.2.

Part: BEARING — FAILED (NR 4 PINION)

THE ENGINE CHIP DETECTOR LIGHT ILLUMINATED IN CRUISE FLIGHT OVER THE GULF OF MEXICO. THE PILOT LANDED THE HELICOPTER ON NEAREST OFFSHORE PLATFORM, APPROXIMATELY 7 MILES AWAY. MAINTENANCE INSPECTED THE CHIP DETECTOR PLUGS AND FOUND THE LOWER PLUG COVERED WITH METAL SHAVINGS AND A PIECE OF METAL .50 INCH LONG BY .25 INCH WIDE. THE ENGINE WAS REPLACED ON THE OFFSHORE PLATFORM. SUBSEQUENT EXAMINATION OF THE ENGINE REVEALED THE NR 4 PINION BEARING ROLLER CAGE HAD FRACTURED. A LARGE PIECE OF THE ROLLER CAGE WAS MISSING.

Part: SEAL — LEAKING (ENGINE GEARBOX)

DURING FLIGHT, THE TRANSMISSION PRESSURE CAUTION LIGHT ILLUMINATED. THE PRESSURE GAUGE INDICATED 30 PSI. DURING FINAL APPROACH, PRESSURE DROPPED TO 20 PSI AND TO 10 PSI DURING HOVER. UPON LANDING, PRESSURE RETURNED TO 25 PSI. AIRCRAFT WAS INSPECTED AND THE TRANSMISSION OIL LEVEL WAS FOUND LOW. THE ENGINE GEARBOX SEAL WAS DETERMINED TO BE LEAKING. SEALS WERE REPLACED. ENGINE OIL AND EXTERNAL FILTER WERE CHANGED. TRANSMISSION CHIP PLUGS WERE ALSO CHECKED. NO DEFECTS NOTED.