Figure 4-2. Tandem Rotor Powertrain
(f) Oil cooler inspection. Inspect gear
box oil cooler in accordance with the applicable aircraft
inspection requirements manual. Replace oil cooler
assembly after gearbox failure and attach metal tag to
FAILURE, DECONTAMINATE AT SPECIFIED DEPOT.
(g) Accessory inspection. Gearbox
accessories shall be inspected in accordance with the
Damaged or worn gearbox accessories shall be replaced
in accordance with instructions contained in applicable
(2) Preservation for shipment. Use the
following procedures to preserve gearboxes for shipment:
(a) Drain oil from gearbox.
(b) Plug all openings and fill gearbox
with corrosion preventive, MIL-C-6529, Type II. Do not
mix corrosion preventives and lubricating oils unless they
(c) Rotate gears to accomplish internal
sloshing required for preservation.
(d) Drain corrosion preventive mixture
(e) Coat all unprotected surfaces such
as shafts with hard-film corrosion preventive compound,
MIL-C-11796, and cover coated area with grease proof
barrier material, MIL-B-121.
(f) Attach warning tag with following
notation: GEARBOX PRESERVED. REFILL WITH
PROPER LUBRICANT, FLUSH, DRAIN, AND REFILL
WITH PROPER LUBRICANT BEFORE OPERATING.
(g) Pack gearbox securely in suitable
(3) Depreservation. Depreserve gearboxes
using the following procedures:
(a) Remove gearbox from shipping
container, and remove grease proof paper and tape.