IranAir Flashcards
The FAULT light comes on amber on the APU bleed pushbutton switch when;
The system detects an APU leak
When APU master switch is selected to OFF;
APU keeps running for a cooling period of 120 sec. at 100% speed.
when the APU fuel feed pressure is low;
A special fuel pump that is run off the ESS AC SHED or AC STAT INV BUS supplies fuel
When the APU is running the APU fuel pump :
Runs when tank pumps pressure is not sufficient
With nobody in the cockpit ,if you have an APU FIRE, which statement is correct ?
On the ground , an APU EMER shut down will occur and the APU fire bottle will discharged automatically
Fire on ground or in flight will cause the APU MASTER SW pushbutton FAULT light to come on
FALSE
With battery power ,what would and APU fire test look like ?
APU FIRE pushbutton illuminated .
SQUIB and DISCH light illuminated .
The starter engages if the APU air intake is closed and the MASTER SW and the START pushbuttons are ON .
FALSE
The APU may obtain power for starting from :
ground services .
Normal aircraft supply .
The aircrafts batteries or in combination with the external power .
The APU cannot be shut down from outside the aircraft
FALSE
What of some of the causes for an APU automatic shutdown ?
fire ( on ground only), under speed , over speed , EGT over temperature , Reveres flow , low oil pressure, DC power loss
Maximum altitude for APU bleed operation is :
20,000 ft
The APU is supplied from the
Left fuel feed line
ON ground , the No break Power Transfer function is inhibited in case of APU shut down generated by which of the following conditions ?
Automatic APU shut down triggered by the ECB.
APU shut down from the REFUEL/DEFUEL panel from the APU FIRE pushbutton .
APU shut down from emergency control provided on the external power panel.
Can the APU be used with wing anti-ice on ?
No, but only for electrical power .The APU bleed valve should not be opened while using wing anti-ice .
To start the APU the:
BAT 1 and 2 push buttons must be selected to ON.
What is the function of the APU GEN push button located on the overhead electrical panel?
When selected OFF, the APU generator is de-energized.
It is normally left in the lights out position
When the APU MASTER SW is selected ON
the APU computer automatically completes a self-test, opens the air intake flap and supplies fuel pressure.
The APU may be started up to what altitude?
The APU can be started at any altitude provided normal aircraft electrical power is available.
With the engines off, if the AVAIL light is illuminated on both the APU START push button and the EXT PWR push button, what is the source of electrical power for the aircraft busses?
The APU.
The APU START push button, when selected ON, will:
start the APU if the APU MASTER SW was previously selected ON
The APU system page will appear on the ECAM:
automatically whenever the APU is started and AC power is available.
when selected by the crew.
If an APU fire occurs on the ground
The APU shuts down and the fire extinguisher discharges automatically
The APU bleed P/B is selected ON
Provided APU speed is greater than 95% the APU valve opens , the Xbleed valve opens , and the engine bleed valves automatically close
The Electronic Control Box (ECB) is primarily a full authority digital electronic
controller that performs the APU system logic for all modes of APU operation such as:
Sequence and monitoring of start.
Speed and temperature monitoring.
Monitoring of bleed air and shut down
When the APU Master Switch is released, a normal APU shutdown occurs:
With a delay if the bleed air was in use.
When selected on, the APU START push button, will
Start the APU if the APU MASTER SW was previously selected ON
The APU has an integral independent lubrication system for lubrication and cooling
True
The ECB ( Electronic Control Box) controls the APU fuel flow.
True
The APU MASTER SW FAULT light will illuminate
When an automatic shutdown of the APU occurs
You switch off the APU but curiously you still have the APU AVAIL indications
The APU will run for a cooling period of 60 to 120 seconds because you have been using the APU bleed
With the engines off, if the AVAIL light is illuminated on both the APU START push button and the EXT PWR push button, what is the source of electrical
power for the aircraft busses?
The APU.
When the APU is running, the APU fuel pump:
Runs when tank pumps pressure is not sufficient
The APU BLEED valve is automatically closed above ____feet by the ECB.
23,000 feet
With nobody in the cockpit, if you have an APU FIRE, which statement is correct?
On the ground, an APU EMER shut down will occur and the APU fire bottle will be discharged automatically
The basic element of the APU is a single shaft gas turbine which delivers _____power for driving the accessory gearbox (electrical generator) and produces bleed air (engine starting and pneumatic supply).
Mechanical shaft .
With battery power, what would an APU fire test look like?
APU FIRE pushbutton illuminated.
SQUIB and DISCH lights illuminated
The APU cannot be shut down from outside the aircraft,
False.
What are some of the causes for an APU automatic shutdown?
Fire (on ground only), under speed, over speed, EGT over temperature, Reverse flow, Low oil pressure, DC power loss.
