DOC AIRBUS | AMM A320FFAN COWL - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. General
The fan cowl door assemblies are interchangeable units. They enclose the engine fan case between the air intake cowl and fan thrust reverser. Three hinges at the pylon support each assembly. The door assemblies are latched along the bottom centerline with three adjustable tension hook latches.
To improve take-off performance, aerodynamic strakes have been installed on the inboard and outboard fan cowls of each nacelle.
** ON A/C NOT FOR ALL The fan cowl door assemblies are interchangeable units. They enclose the engine fan case between the air intake cowl and fan thrust reverser. Three hinges at the pylon support each assembly. The door assemblies are latched along the bottom centerline with three adjustable tension hook latches.
Fan Cowl DoorsTo improve take-off performance, aerodynamic strakes have been installed on the inboard and outboard fan cowls of each nacelle.
2. Description
The fan cowls are bonded graphite epoxy skins and aluminum honeycomb sandwich construction.
A land is formed with the air intake cowl at the forward end, and with the fan thrust reverser at the aft end.
Both lands incorporate an edge protector. The forward land incorporates 4 interchangeable alignment fittings.
A bulb-type seal is provided along the lower longitudinal splitline. A sheet metal seal is provided along the upper longitudinal splitline.
Strakes are installed on the inboard and outboard fan cowls of each nacelle.
An electrical bonding strip, which is connected to the strake backplate and the fan cowl locator blade provides an electrical bond between the strake and the engine.
The fan cowls are bonded graphite epoxy skins and aluminum honeycomb sandwich construction.
A land is formed with the air intake cowl at the forward end, and with the fan thrust reverser at the aft end.
Both lands incorporate an edge protector. The forward land incorporates 4 interchangeable alignment fittings.
A bulb-type seal is provided along the lower longitudinal splitline. A sheet metal seal is provided along the upper longitudinal splitline.
Strakes are installed on the inboard and outboard fan cowls of each nacelle.
An electrical bonding strip, which is connected to the strake backplate and the fan cowl locator blade provides an electrical bond between the strake and the engine.
A. Opening/Closing
There are two telescopic hold open rods on each door. When extended the hold open rods are positioned into brackets on the engine fan case. They support the fan cowl doors in the open position. A 40-degree position serves for routine maintenance and a 55-degree position serves for increased access.
There are two telescopic hold open rods on each door. When extended the hold open rods are positioned into brackets on the engine fan case. They support the fan cowl doors in the open position. A 40-degree position serves for routine maintenance and a 55-degree position serves for increased access.
B. Access Doors
Access door 438CR (448CR) in the right fan cowl door provides access to the starter valve manual override.
Access door 437BL (447BL) in the left fan cowl provides access for:
Access door 438CR (448CR) in the right fan cowl door provides access to the starter valve manual override.
Access door 437BL (447BL) in the left fan cowl provides access for:
- engine oil service,
- inspection of the hydraulic filter clogging.
C. Pressure Relief Door 438BR (448BR)
A pressure relief door located in the right cowl door limits compartment pressure to a maximum of 4 psig. In addition, a compartment cooling air inlet is located in the lower quadrant of the left cowl door.
The air inlet directs air toward the accessory gearbox. In the upper quadrants of the left and right cowls there are five air outlet vents.
The fan cowl doors are:
A pressure relief door located in the right cowl door limits compartment pressure to a maximum of 4 psig. In addition, a compartment cooling air inlet is located in the lower quadrant of the left cowl door.
The air inlet directs air toward the accessory gearbox. In the upper quadrants of the left and right cowls there are five air outlet vents.
The fan cowl doors are:
- fire proof with external air flow,
- fire proof without external air flow above 45 degree radial,
- fire resistant without external air flow below 45 degree radial.
D. Fan Cowl Structure
The internal pressure loads and external air loads are reacted through the honeycomb structure. They are transmitted into the pylon through the hinge fittings. The door lands provide support to prevent deflection under pressure. The cowl doors, when completely latched, provide hoop continuity.
The cowl doors are designed to be structurally adequate when any one latch is unlatched or any one hinge failed . A nacelle overpressurization condition due to a pneumatic duct failure is released through the pressure relief door.
The internal pressure loads and external air loads are reacted through the honeycomb structure. They are transmitted into the pylon through the hinge fittings. The door lands provide support to prevent deflection under pressure. The cowl doors, when completely latched, provide hoop continuity.
The cowl doors are designed to be structurally adequate when any one latch is unlatched or any one hinge failed . A nacelle overpressurization condition due to a pneumatic duct failure is released through the pressure relief door.