DOC AIRBUS | AMM A320FFAN CASE - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
A. Fan Case Assembly
(1) The fan rotor is housed in the fan case assembly. The function of the fan case assembly is to contain and make the fan airflow straight, to give protection and containment for a fan blade failure and to supply structural attachment points between the inlet cowl and the core engine. The inner case has acoustic liners to decrease noise at the front and rear of the case, a rubstrip liner for the fan blades and a liner which supplies protection from ice. At the rear of the fan case assembly is an aluminum support ring which has a "V" groove that supplies alignment and functions as a support for the thrust reverser doors. The fan case assembly also includes 48 Fan Exit Guide Vanes (FEGVs). They are located at the rear of the fan case and extend diagonally forward to the Fan Intermediate Case (FIC) to function as a support for the fan case and make the bypass air straight.
Fan Case AssemblyA. The fan case is a one-piece composite case whose inner surface is the outer flow path for fan air. The fan case assembly contains and directs the fan bypass air through the FEGVs and provides containment in the event of a fan blade fracture.
(1) The inner surface of the fan case has acoustic treatment in the forward and aft areas of the case.
(2) In the middle of the fan case is a rubstrip liner for the fan blades, followed by the ice liner, which provides protection from ice.
(3) An aluminum support ring is installed at the rear of the fan case. The support ring is attached to the fan case by screws that attach each FEGV to the fan case.
B. The FEGV's are hollow and made of an aluminium composite. The FEGV's extend diagonally rearward from the outer diameter of the FIC to the inner diameter of the fan case.
(1) The FEGV's straighten the fan bypass air and provides radial support for the fan case.
(2) A titanium strip is bonded to the forward edge of the blades to protect against erosion.
C. There are six fan exit liner segments that are located aft of the FEGV's and are installed radially around the outer diameter of the Low Pressure Compressor (LPC).
(1) All the fan exit liner segments are made of a composite material.
(2) Five of the six liner segments are a two piece design that consist of a forward bleed duct liner segment and an aft fan exit liner segment.
(3) The fan exit liners form the inner diameter flow path for the fan bypass air.
(4) The forward bleed duct segments have large rectangular slots covered by protective screens that provide an exit path to vent the LPC bleed air when the 2.5 bleed actuator opens.
D. The fan exit fairing assembly (upper bifi) is located rear of the upper FEGVs and extends from the outer diameter of the LPC firewall to the rear flange of the fan case and diverts the fan exit air around the pylon.
(1) The assembly is a three-piece design made from titanium that consists of the left, right and forward sections.
(2) A pair of safety cables is used to retain the left and right sections to the forward section when the engine is off-wing.