I.
The upper sidewall includes three hinge clevises, opening actuator fitting and three deflection limiters and wear pads.
J.
The lower duct sidewall includes two deflection limiter wear pads, three lower latch assemblies with alignment pins, hinged lower access panels, on the right half assembly or access panel latches on the left half assembly.
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K. The inner cowl is an aluminum honeycomb bondment which makes an aerodynamic inner flow surface for the fan duct. The inner cowl is attached by rivets to the duct sidewalls. On the forward edge of the inner cowl, a vee flange engages a groove on the fan frame. A faying surface to underlap the core cowl is on the aft inner cowl surface. Six hinge fittings for blocker door drag links are attached to each inner cowl. An air duct penetrates the inner cowl for the fan air pre-cooler.
L. The torque box is a riveted and bolted framework of aluminum sheet and extrusions to hold the translating cowl and the vaned deflector assembly. It is attached by rivets to the duct sidewalls. It is held and stiffened by the forward thrust ring which engages a vee on the fan case and is attached by clamps to the fan case by the circumferential latch band.
3. Translating Sleeve (Fig. 3)
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A. The translating sleeve is a bonded honeycomb structure that goes on the two sides of the cascades for forward thrust operation. The outer wall of the translating sleeve is the outer surface of the fan nacelle while the inner wall is the internal surface of the fan duct outer wall. The inner wall of the translating sleeve also holds the blocker doors. The inner and outer walls of the translating sleeve join together at their trailing edge and become the exit lip of the fan cruise nozzle.
B. The inner wall of the translating sleeve is attached to the C duct with two axial tracks and sliders installed at the top and bottom of each C duct. A cylindrical track is made into the aluminum track forging installed on the stationary part of the C duct. The track is lined with a nickel plated stainless steel insert. A low friction material (Rulon J) is bonded to the mating cylindrical slider installed to the translating sleeve to make sure of a smooth translation. The track and slider transmits the hoop tension loads of the duct outer wall into the nacelle structure and also acts as a seal against the duct's internal pressure in the forward thrust mode.
C. An auxiliary track and slider similarly carries the hoop tension loads on the outer wall of the translating into the duct structure. The hoop tension in the outer wall is made by aerodynamic impingement pressure from the cascade exhaust that occurs during translating sleeve translation and operation in reverse thrust.
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BLOCKER DOOR SUPPORT ASSEMBLY A-A
Translating Sleeve Figure 3
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D. A bulb type seal along the forward edge of the inner wall of the translating sleeve prevents fan duct leakage during forward thrust operation.
E. Deactivation of the thrust reverser is done when deactivation bolts are installed in the holes in each thrust reverser sleeve. Bolt heads are painted red to show the deactivation of the thrust reverser. Bolts are stored on the torque box.
F. Two translating sleeves are installed on each engine, one for each thrust reverser half. There is no interconnection between the translating sleeves.
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