Monday, August 1, 2005
SDRs and MXAlerts
Raytheon (Beech) B300: A mechanic stated that during a normal phase inspection of the Engine Inertial Vane Control System it was found that the retainer plate (P/N 101-910114-35), which locks into a groove on the shaft (P/N 101-910114-129), for the aft inertial vane was not installed correctly. When the retainer plate is correctly installed in the groove on the shaft assembly, it would securely hold the assembly in its mounting plates. This retainer plate is located on the vane shaft end opposite the actuator. This (improper) situation allowed the shaft assembly to move back and forth when the vane is operated through its normal range. The submitter stated that they have found this excess side movement would also allow the bolt that secures the shaft assembly to the actuator to possibly catch on the surrounding support. This condition was found on both engines of the aircraft. The shaft assemblies for the forward vanes were found to be correctly installed.
BEECH 400A, P&WC JT15D1: Crew squawked electrical fumes and foul odor in cockpit. Odor seemed to let up after battery switch was placed in emergency and both generators placed in emergency. Maintenance found right windshield heat current sense relay (L102S) terminal B and approximately two inches of wire insulation to overheat and melt with right windshield heat on and windshield subjected to cold temperatue. Found wire amp end secured to subject relay terminal stud with flat nut and washer. No lock washer was installed. Lack of a lock washer under nut enabled terminal nut to become loose and arc under current load. Replaced defective wire and relay with new. Utilized new lock washers under new nuts at replacement relay term studs. Cockpit system checked normal.
SIKORSKY, TURBOMECA: On the engine anti-ice system, heated intake bellmouth, and heated snow blanket, maintenance found a burned 16 gage wire at plug J701 and P701 (pin A). They also found this wire was fed by a 35 amp cockpit DC primary bus circuit breaker through a 10 gage wire to plug J3004K and P3004K pins F and C. The 16 gage wires (two each) were butt connected together to a single 10 gage wire. One of the 16 gage wires was burned completely through. Upon repairing the burned wire, the mechanic found that the 10 gage and 16 gage wire showed signs of copper oxidation, were brittle to the touch, and the silver plating on the wire was flaking off. Further investigation showed that this may be a manufacturing defect. Further investigation ongoing with manufacturer.