DOC AIRBUS | AMM A320FFAN COWL - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. General
The Left Hand (LH) and Right Hand (RH) fan cowl assemblies enclose the engine fan case between the air intake cowl and the thrust reverser. Each door is interchangeable from one engine to the other and is attached to the pylon by two hinges. A third hinge at the forward end of each door connects to a common tie link between each door.
The doors are latched together along the bottom center line by three adjustable tension hook latches.
Each fan cowl has a strake attached to it. The strake helps give smooth airflow between the cowl and the fuselage to decrease turbulence. The strakes are attached to the cowl with screws and jointing compound. The fan cowl doors are interchangeable side by side.
** ON A/C NOT FOR ALL The Left Hand (LH) and Right Hand (RH) fan cowl assemblies enclose the engine fan case between the air intake cowl and the thrust reverser. Each door is interchangeable from one engine to the other and is attached to the pylon by two hinges. A third hinge at the forward end of each door connects to a common tie link between each door.
Fan Cowl DoorsThe doors are latched together along the bottom center line by three adjustable tension hook latches.
Each fan cowl has a strake attached to it. The strake helps give smooth airflow between the cowl and the fuselage to decrease turbulence. The strakes are attached to the cowl with screws and jointing compound. The fan cowl doors are interchangeable side by side.
2. System Description
A. General
(1) LH Fan Cowl Door
(a) The primary components of the LH fan cowl doors are as follows:
- Access door for the starter valve installation
- Access door for the Integrated Drive Generator (IDG)
- Access door for the interphone jack (optional)
- Hold Open Rod (HOR) fitting and storage
- Strake fittings
- Hoisting points
- Rubstrips
- Identification plate
- Hinge fittings
- Keepers
- Keeper housings
- HOR (forward and rearward)
- Forward (FWD) guide ramp
- Rearward (RWD) guide ramp
- Upper and lower locator
- Bonding strap
- Ventilation grid
- Sensors
- Electrical harness and electrical support
- Mechanical cowl loss prevention system: flag box assembly, teleflex and lever.
(b) Dimensions:
- Length: 1576.5 mm (62.067 in.)
- Width: 1312.3 mm (51.665 in.)
- Height: 2488.4 mm (97.969 in.)
- Weight: 56.7 kg (125.00 lb).
(2) RH Fan Cowl Door
(a) The primary components of the RH fan cowl doors are as follows:
- Access door for the oil tank
- Oil tank door frame
- HOR fitting and storage
- Strake fittings
- Hoisting points
- Rubstrips
- Identification plate
- Hinge fittings
- Latches
- Latch housing
- HOR (forward and rearward)
- Forward guide ramp
- Rearward guide ramp
- Upper and lower locator
- Bonding strap
- Ventilation grid
- Protection plate.
(b) Dimensions
- Length: 1576.5 mm (62.067 in.)
- Width: 1263.96 mm (49.762 in.)
- Height: 2488.4 mm (97.969 in.)
- Weight: 46.7 kg (102.96 lb).
B. Component Description
(1) Fan Cowl Door Structure
The fan cowl doors are made of Carbon-Fiber Reinforced Plastic (CFRP) panels. Fan cowl doors have longitudinal and transversal composite stiffeners.
The two fan cowl doors make link with the air intake cowl at the forward end. The outer skin of the fan cowl doors includes a bronze mesh to help in external electrical conductivity and to decrease direct and electromagnetic lightning effect.
The split line of the fan cowl doors makes sure that the fan compartment drainage is effective.
The fan cowl doors are made of Carbon-Fiber Reinforced Plastic (CFRP) panels. Fan cowl doors have longitudinal and transversal composite stiffeners.
The two fan cowl doors make link with the air intake cowl at the forward end. The outer skin of the fan cowl doors includes a bronze mesh to help in external electrical conductivity and to decrease direct and electromagnetic lightning effect.
The split line of the fan cowl doors makes sure that the fan compartment drainage is effective.
(2) Hinge Fittings
Two hinge fittings connect the fan cowl doors, at their top end, to the pylon. The third hinge, at the forward end of the fan cowl doors connects the fan cowl doors together through a link bar.
Two hinge fittings connect the fan cowl doors, at their top end, to the pylon. The third hinge, at the forward end of the fan cowl doors connects the fan cowl doors together through a link bar.
(3) Latches and Keepers
Three latches and keepers lock the fan cowl doors together along the bottom centerline.
The right fan cowl door has three hook-type latches that engage with three keepers on the left fan cowl door. These latches and keepers engage in their related housings. The keeper housing has a spigot that helps to align the keeper with its latch. The latch handle is used when the latch is not correctly engaged with its keeper.
The latches and keepers are made of steel and housings are made of titanium.
Three latches and keepers lock the fan cowl doors together along the bottom centerline.
The right fan cowl door has three hook-type latches that engage with three keepers on the left fan cowl door. These latches and keepers engage in their related housings. The keeper housing has a spigot that helps to align the keeper with its latch. The latch handle is used when the latch is not correctly engaged with its keeper.
The latches and keepers are made of steel and housings are made of titanium.
(4) HORs
There are two HOR assemblies (forward and rearward) in each fan cowl door to keep it in the open position for ground maintenance tasks. The ends of the HOR are attached to fittings in the fan cowl. The HOR FWD is permanently attached to the engine case. For the transportation of the fan cowl door on ground, the HORs must be engaged on storage fittings. The HORs lock automatically in the open positions when the fan cowl doors are at 55 degrees.
To unlock the HOR RWD it is necessary to move the manually locking sleeve from green position to red position.
Move to forward position the HOR FWD in order to disengage the locking sleeve from extension position. Colored indicators show the HOR position:
There are two HOR assemblies (forward and rearward) in each fan cowl door to keep it in the open position for ground maintenance tasks. The ends of the HOR are attached to fittings in the fan cowl. The HOR FWD is permanently attached to the engine case. For the transportation of the fan cowl door on ground, the HORs must be engaged on storage fittings. The HORs lock automatically in the open positions when the fan cowl doors are at 55 degrees.
To unlock the HOR RWD it is necessary to move the manually locking sleeve from green position to red position.
Move to forward position the HOR FWD in order to disengage the locking sleeve from extension position. Colored indicators show the HOR position:
- RED: CLOSED position and unlocked (0 to 55 degrees)
- GREEN: FULL OPEN position, locked at 55 degrees.
(5) LH Fan Cowl Door Access Panels
The left fan cowl has access panels for maintenance tasks. There are also outlets to release the air from the fan compartment and to prevent too much pressure in the fan case compartment. The left fan cowl also has:
The left fan cowl has access panels for maintenance tasks. There are also outlets to release the air from the fan compartment and to prevent too much pressure in the fan case compartment. The left fan cowl also has:
- An access door to the starter valve
- Access door for the IDG
- Access door for the interphone jack, (interphone jack is an optional fan cowl door element)
- Ventilation grid.
(6) RH Fan Cowl Door Access Panels
The right fan cowl has access panel for maintenance tasks. There are also outlets to release the air from the fan compartment and to prevent too much pressure in the fan case compartment. The right fan cowl also has:
The right fan cowl has access panel for maintenance tasks. There are also outlets to release the air from the fan compartment and to prevent too much pressure in the fan case compartment. The right fan cowl also has:
- An oil tank access door for oil tank servicing
- Ventilation Grid.
(7) Upper and Lower Axial Locators
Two axial locators (upper and lower) installed at the FWD edge of the left fan cowl engage in receptacles on the air intake.
These axial locators align the fan cowl door in the closed position and prevent axial movement.
The axial locators are made of corrosion resistant steel.
Two axial locators (upper and lower) installed at the FWD edge of the left fan cowl engage in receptacles on the air intake.
These axial locators align the fan cowl door in the closed position and prevent axial movement.
The axial locators are made of corrosion resistant steel.
(8) FWD and RWD Guide Ramps
A FWD guide ramp is installed at the bottom FWD edge of the fan cowl. It helps to close and prevent movement of the fan cowl.
The FWD guide ramp is made of corrosion resistant steel.
The RWD guide ramp assembly helps the door to reach its position when closing it.
The FWD and RWD guide ramps are made of corrosion resistant steel.
A FWD guide ramp is installed at the bottom FWD edge of the fan cowl. It helps to close and prevent movement of the fan cowl.
The FWD guide ramp is made of corrosion resistant steel.
The RWD guide ramp assembly helps the door to reach its position when closing it.
The FWD and RWD guide ramps are made of corrosion resistant steel.
(9) Hoisting Points
There are three hoisting points on the fan cowl. Each hoisting point has two threaded holes.
Filler plugs are installed in the threaded holes to make the hoisting points flush with the skin of the cowl.
There are three hoisting points on the fan cowl. Each hoisting point has two threaded holes.
Filler plugs are installed in the threaded holes to make the hoisting points flush with the skin of the cowl.
(10) Strakes
All fan cowl doors have structural attachments for installation of the strake. The strakes give better flow separation on the wing top surface during certain phases of flight.
The strake fitting has oblong holes to absorb thermal expansion differences between the strake made of aluminum and the skin made of CFRP.
A metallic bonding strap, installed in the inner surface of the fan cowl door, gives an electrical connection between the strake and the aircraft through the hinges.
All fan cowl doors have structural attachments for installation of the strake. The strakes give better flow separation on the wing top surface during certain phases of flight.
The strake fitting has oblong holes to absorb thermal expansion differences between the strake made of aluminum and the skin made of CFRP.
A metallic bonding strap, installed in the inner surface of the fan cowl door, gives an electrical connection between the strake and the aircraft through the hinges.
(11) Mechanical Cowl Loss Prevention System
The mechanical cowl loss prevention system shows mechanically if the keeper No. 1 is open.
The mechanical cowl loss prevention system components are as follows:
The mechanical cowl loss prevention system shows mechanically if the keeper No. 1 is open.
The mechanical cowl loss prevention system components are as follows:
- Flag assembly
- Teleflex
- Lever.
(12) Sensors and Electrical Harness
An electrical system composed with sensors and electrical harness, give the information to the pilot if the fan cowl doors are not closed.
An electrical system composed with sensors and electrical harness, give the information to the pilot if the fan cowl doors are not closed.