59-25-04 LOCKHEED: Applies to All Model 188 Series Aircraft - Serial Numbers 1002 Through 1072.
Compliance required as indicated.
Insufficient clearance between the generator feeder wires and the leading edge rib at wing Station 221 together with deflection of the leading edge has resulted in abrasion of the insulation on the generator feeder wires and grounding of the generator feeder.
(a) Inspect for evidence of abrasion not later than the next 8 hours' time in service with a light and mirror through fillet access doors N125 and N126 left and right without lowering the leading edge section. If the inspection shows evidence of abrasion, additional spacers must be installed prior to the next flight to obtain a minimum 0.38-inch clearance with the flange of the leading edge rib. If no evidence of abrasion is present, the inspection must be repeated at intervals of 60 hours' time in service but not to exceed 250 hours' time in service when additional spacers must be installed to provide at least 0.38-inch clearance.
Functionally test the generator differential protection system in accordance with Lockheed Maintenance Manual, Section 24-1-0, page 201.
(b) Within the next 250 hours' time in service inspect all wiring in the leading edge and power plant sections for actual or incipient abrasion of wires. If abrasion of wires or insufficient clearance is found, the conditions are to be corrected prior to the next flight.
(Lockheed Electra Alert Service Bulletin 376 covers this same subject.)