47 Questions
What are the key elements of APU lubrication and starting systems?
Load Gearbox and Accessory Gearbox
What drives the two generators and the dedicated oil pump for generator lubrication?
Load Gearbox
What Gearbox is driven by the starter and drives the APU engine oil pumps?
Accessory Gearbox
The APU starting system can be energized by?
APU battery or from the A/C DC network (external power for ground operations).
APU emergency shutdown is located at?
The Nose Landing Gear (NLG) control panel and at the Integrated Refuel Panel (IRP).
Controls and monitors APU start, operation and shutdown (normal and emergency
Electronic Control Box (ECB)
What are the two APU oil sub-systems?
The Main Engine Section lubrication, The APU Electrical Generation lubrication.
Where does the oil store in the APU for the Main Engine Section and Electrical Generation Section?
In a single tank, which has separate compartments for the Generator section and the Main Engine Section.
On APU Oil tank, how does the tank filled with oil?
The tank has common filler, which lets the generator section be filled first, and then the oil flows into the main engine section.
Where can you check the oil level for Generator Section and Main Engine Section?
The oil tank has two external oil level indicators:
A sigh glass for the main engine section.
A bulls-eye for the generator section.
An APU overboard drain outlet is installed on what location?
RH APU DOOR
An APU overboard drain outlet is installed on the R/H APU door. It is connected to the AGB drain and Starter Drain Pad to drain?
Fuel and Oil for AGB Drain and Oil for Starter Drain Pad
To access APU, APU maintenance access door must be open.
APU maintenance access door latching system has?
4 latching hooks. 8 pin latches. A locking device to operate a safety shaft. A hold open rod, attached between the doors structure and the fuselage structure limits the opening of the doors.
APU location in Airbus A380?
The APU is installed at a 15° angle in a fireproof compartment of the aircraft tail cone. Two maintenance doors at the bottom of the tail cone structure give access to the APU.
What protects the air intake against precipitation or against the ingestion of fluids generated on the fuselage?
A Rain Gutter which is installed forward of the air intake.
The APU Air Intake is located on?
The upper RH side of the aircraft fuselage.
How does the APU compartment ventilated?
A cooling air duct gets external air from a cooling air inlet located on the upper LH side of the tail cone, to ventilate the APU compartment.
Releases combustion gases into the atmosphere and suppress APU generated exhaust noise?
Exhaust Muffler
The APU has 4 attachment points connected to how many airframe mounts?
3 airframe mounts
Supplies sufficient ambient air to the APU air plenum chamber during ground or flight conditions, and its design maintains a low noise level with optimum aerodynamic flow?
Air Intake System
Air Intake Flap is controlled by?
Controlled by ECB and is fully open throughout the APU operation. It will close when the APU is shut down.
Reduces the possibility of foreign object ingestion and prevent against ingestion of fluids and of hot APU gases into Air Intake?
The rain gutter and the anti-ice fence
APU and GEN oil system are?
Independent and each has own pressure system to deliver the oil to the users, and a scavenge system to return the oil to the tank.
When does oil cooling took place?
Oil Cooling is done on the pressure supply circuit before the oil goes through the filter.
Where does the Main (APU) OIL PUMP installed?
Accessory Gearbox
The Generator OIL PUMP is installed in?
Load Gearbox
How many Scavenge Pump are there in Accessory Gear Box?
Three
How many Generators Scavenge Pump are there in Load Gearbox?
Two
Installed just downstream of each oil pressure pump. The valves are used as a safeguard against excessive pressure build-up during cold weather operation. The valves open and divert oil to the pump inlet if the oil pressures exceed pre-set values.
Cold Start Valve (CSV)
What cools the oil in APU and Generator Oil system?
Air Cooled Air Cooler
Valve in each system which lets cold oil bypass the cooler and flow directly to the filter.
Thermal / Pressure relief valve
Which component is responsible for preventing the oil in the cooler assembly from draining back to the tank at APU shut down?
The pipe-fittings
What is the purpose of the drain valve in each core of the pipe-fittings?
To let the oil drain at the component removal
Why are drain valves installed in each core of the pipe-fittings?
To let the oil drain at the component removal
What prevents oil loss when you replace Main (APU) Oil Filter?
Check Valve
What prevents oil loss when you replace Generator Oil Filter?
Anti-siphon feature is installed upstream of the GENERATOR Oil Filter.
Maintains constant oil system pressure and opens at pre-set oil pressure values and bypass oil to the pressure pumps.
Pressure Regulating Valve
Sensors that measure oil pressure upstream and downstream of the oil filters.
Dual oil pressure sensors
Dual Oil Pressure Sensors inputs are used by the ECB to monitor system oil pressure and identify an impending filter bypass. The downstream channel is used for?
System Oil Pressure
Dual Oil Pressure Sensors inputs are used by the ECB to monitor system oil pressure and identify an impending filter bypass. The Upstream channel is used for?
The upstream channel is used in conjunction with the downstream to calculate filter delta pressure. The upstream channel is also used as backup system oil pressure should the downstream channel fail.
Where does Oil Temperature Sensor installed?
Oil Temperature Sensors are installed downstream of Oil Filter. Inputs from these sensors enable the ECB to monitor the oil temperature of each oil system.
How many electrical chip detectors are installed in each Oil System?
Three Electrical Chip Detector, One in the GEN OIL System Two in the Main (APU) OIL System
What pumps the oil from the load gearbox sump including bearing no. 0 to the Main (APU) OIL tank compartment?
Load Gearbox Scavenge Pump
What pumps oil from bearing No.4 to Accessory Gearbox Cavity?
Bearing No.4 Scavenge Pump
Scavenged oil from Bearings No.1 & 2 and Bearing No.3 flows to AGB cavity by means of?
gravity and secondary air pressure
What pumps oil from AGB cavity back to Main (APU) OIL Tank?
AGB Scavenge Pump
What pumps oil from Generators back to Generators Oil Tank?
GEN Scavenge Pump
Test your knowledge of aircraft APU (Auxiliary Power Unit) lubrication and starting systems with this quiz. Explore the key elements, generators, oil pumps, gearbox, starting system energization, and emergency shutdown procedures for APU operations.
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