DR 611749875 GENERAL ELECTRIC CT7 9B – ATA 7210 TURBINE ENGINE REDUCTION GEAR – PROPELLER SHAFT – SHEARED. During descent, RH Torque indication was observed to fluctuate +/- 3%. Uncommanded engine operation checklist was actioned. Vibration was also felt in the airframe, and observed from the RH propeller spinner. At the completion of the checklist as the RH C/L was moved to FUEL OFF RH propeller assembly departed from the aircraft. The propeller was still rotating and pivoted to a horizontal position travelling over the nacelle and past the tailplane. The engine shutdown was completed and the aircraft landed without further incident. Initial inspection shows the PGB drive shaft has sheared.
DR 611749843 SIKORSKY S92 A – ATA 6720 TAIL ROTOR CONTROL SYSTEM – RIVET – SHEARED RIVETS. During routine inspection, it was found that one of the tail rotor pulley attachment bracket bolt has failed 100 in-lb torque check. Further investigation found FWD inboard anchor nut rivets had sheared – allowing the bolt to be somewhat tightened, but not able to be torqued. Root cause not established as yet, however the main contributing factor was the finding that the bolts of the attachment were installed dry and light surface corrosion was found on the shank and within the bolt holes. Aircraft is approximately three years old and no major maintenance has occurred in this area. Anchor nut plate replaced, corrosion removed from all areas. All bolts, anchor nuts and mounting bracket treated with corrosion preventative compound. Sikorsky will be informed by established means.
DR 611749841 LYCOMING TIO540 V2AD – ATA 8530 RECIPROCATING ENGINE CYLINDER SECTION – PISTON ENGINE – LOW COMPRESSION. Engine rough running. No compression in cylinder # 4.
DR 611749820 GIPPSLAND GA8 – ATA 2497 ELECTRICAL POWER WIRING – WIRING – CHAFED WIRING. During inspection, chaffing on overhead loom found on forward roof panel. Suspected it is due to absence of rubber edge capping.
DR 611749760 PIPER PA44 180 – ATA 5740 WING, ATTACH FITTINGS – FITTING – HOLE WORN ELONGATED. Whilst carrying out 100 hour inspection, two deep steps in forward RH wing attach bracket bolt were witnessed. At some point, bush in the wing spar assembly had been dislodged or worn to move sideways allowing the larger diameter hole in the bracket to wear into the bolt. The aircraft had been reported flying wing heavy a number of times. Rear wing fitting was also found to be worn beyond limits as stated in Piper SL 1087.Forward wing spar assembly and bolt to be replaced with new items.
DR 611749719 CESSNA 402 C – ATA 3240 LANDING GEAR BRAKE SYSTEM – LINE – Pin hole leak. Brake system unable to hold pressure on landing role. Defect was traced to pin hole leak in supply line. Line repaired.
DR 611749718 CESSNA 208 B – ATA 3242 BRAKE – HOSE – CHAFING. On taxi, no brake pressure on right hand side. Later on, brake hose was found failed (chaffing) near the swage at the end of the hose at the brake end. Hose replaced.