Engines Auxiliary Power Unit (APU) Practice Exam

These questions are part of the practice quiz. Start practicing

• What does the REVERSER LIMITED light on the ground indicate?
• What is the primary purpose of an aircraft APU?
• What does an amber TAI above the N1 gauges indicate?
• Where are fire detection loops typically installed for APU protection?
• What are potential hazards when working around an operating APU?
• During starting the MAX engine, if N2 stagnates at 18%, what is the most likely cause?
• What should be inspected on the APU exhaust area for safe operation?
• In normal mode, if the thrust lever is advanced to the forward stop, the EEC will do what?
• To perform a ground start ignition to the selected igniter, what position should the engine start lever be in?
• Explain the difference between APU start permissives and the actual start sequence?
• In flight, what does the REVERSER LIMITED light indicate?
• The __________ controls and monitors the APU.
• Which of the following is NOT a typical use of APU bleed air?
• Which statement best describes the APU DOOR light status in flight?
• How would you perform an APU fuel system check?
• What is a borescope inspection of an APU and when is it performed?
• Which statement best describes the function of the electronic control unit in relation to the APU?
• Which N2 range is associated with MOTORING on the N2 gauge?
• Which control is used to manually set N1 reference bugs and readouts?
• Which testing option would verify APU shutdown capabilities if a self-test feature is available?
• Which statement about APU auto-shutdown protections is true?
• BRM stands for which term?
• If IGN L or IGN R is selected and the ENGINE START switch is in FLT, what happens?
• What is the purpose of an APU oil cooler and where is it typically located?
• On the MAX, what does the MOTORING indication on the N2 gauge mean?
• Which action yields entry into hard alternate mode?
• Where are the MAX primary engine indications displayed?
• What is the purpose of the APU fuel system and how does it prevent fuel leaks or uncommanded starts?
• Which electrical buses are shed when the APU is the sole power source in flight?
• Which color MAINT light on the APU panel indicates an APU maintenance problem?
• Why are borescope inspections used in APU maintenance?
• Which indication confirms BRM is active during start on the MAX?
• What indicates the APU is ready to provide electrical power?
• Which color is the START VALVE OPEN alert light?
• What is the effect of a defective APU shutoff valve?
• What is typically used to start an aircraft APU?
• How do you verify that the APU's electrical generator is correctly feeding the aircraft buses after start?
• Which statement best describes the CONT position when the engine is running with the start lever in IDLE?
• Air for APU compartment cooling is drawn from which location?
• Under what conditions can thrust reversers be deployed?
• What does a flashing white box around the EGT during engine start indicate?
• Which of the following is NOT a typical operating limit for an APU?
• Describe events that typically trigger automatic APU shutdown.
• What is the approximate engine starter cutout speed (as a percent of N2) for the NG?
• Which option is NOT a permissible source for starting an engine?
• During engine start, selecting GRD provides electrical power to which system and displays engine parameters?
• How is hard alternate mode entered in the EEC?
• Amber REVERSER light on the overhead panel causes MASTER CAUTION and ENG lights to illuminate after approximately how many seconds?
• What safety devices are involved with APU fire detection and suppression?
• Describe the normal steps of a typical APU start sequence.
• Fuel is normally supplied to the APU from which side of the fuel manifold when AC fuel pumps are operating?
• On the MAX engine display, what does the additional FUEL FLOW warning light indicate?
• Name the major sections of a gas turbine APU.
• How long are ENGINE CONTROL lights inhibited after touchdown?
• How is cross-bleed sequencing coordinated between the APU and engine start?
• Which maintenance action is performed on the APU air intake to ensure proper airflow?
• When the APU is shut down by turning OFF, what is the status of the APU GEN OFF BUS light?
• In soft alternate mode, does the EEC redline overspeed protection apply to N1 and N2?
• The EEC redline overspeed protection for N1 and N2 is provided in which modes?
• If the EEC detects flameout, which igniters are activated?
• The EEC has how many control channels?
• Which sensors provide critical data for APU control and what do they monitor?
• Which indication shows the MAX APU is running?
• What does an amber REV displayed above the N1 gauges on the center instrument panel indicate?
• Which action is performed to maintain airflow in the APU air intake during maintenance?
• After ENGINE START switch has been selected to GRD, which indication shows the EEC is performing BRM?
• On the ground, what is the expected end state when the APU is fully operational?
• If the EEC normal mode is not available, to which mode does the EEC downgrade?
• If an uncontrollable N2 overspeed is detected, what does the Electronic Overspeed System (EOS) command the EEC to do?
• Which component is an Electronic Control Unit (ECU) used to manage APU operations?
• What is the purpose of APU load control and how does it manage start/stop?
• The REVERSER AIR/GRD light illuminates when?
• What color indicates engine oil pressure and temperature indications in the caution range?
• Under what engine condition does the ENG FAIL alert appear within the EGT display?
• The EEC provides N1 and N2 redline overspeed protection in which modes?
• Which indicator shows the air/ground thrust reverser logic has failed?
• What happens when the APU switch is moved to OFF?
• Which indicators would confirm an APU is ready to supply electrical power?
• In the described condition, what does placing the engine start switch in CONT provide?
• Maximum reverse thrust detent position is which number?
• What does the EEC redline overspeed protection do to engine speeds?
• When does the spar fuel shutoff valve open?
• When are borescope inspections or overhauls typically performed on an APU?
• What does a green REV indication above the N1 RPM readout indicate?
• What prestart checks should be performed before starting the APU on the ground?
• What is the purpose of securing doors and panels before APU start?
• What does an amber FAULT light on the APU panel indicate?
• During normal start sequences, ignition is supplied to which igniters?
• When does engine idle speed increase to approach idle?
• Which power source powers the right igniter?
• What color is the START VALVE OPEN alert light?
• How do you determine APU readiness without an on-wing test?
• Which indicator shows the auto-restow circuit activation?
• How are bleed air leaks detected and mitigated around the APU?
• How is the thrust reverser operated?
• When the MAX APU DOOR light is illuminated on the ground, what does this indicate?
• What is the role of the APU accessory drive gearbox?
• Which of the following is a typical indicator that the APU is in start or run mode?
• List typical APU operating limits that must be observed during start/operation.
• Which statement describes proper readiness indicators for the APU on the ground?
• Which component is faulted when REVERSER LIMITED indicates a limit on reverse thrust?
• On which instrument panel is the green REV displayed above the N1 gauges used to indicate reverser deployment?
• If the APU automatically shuts down due to overspeed, what steps should be taken?
• START VALVE OPEN amber light indicates?
• The ENGINE CONTROL lights operate on the ground only, with engines operating and aircraft speed below how many knots?
• What combination causes the engine fuel shutoff valve to open?
• What are the primary hazards to be aware of when working around an operating APU?
• Describe how an APU fuel control would respond to a lean fuel condition.
• Where does the ENG FAIL alert appear during engine operation?
• Which option describes the starter operation requirement?
• Where would you find an illuminated amber ENGINE CONTROL light indicating a fault?
• What parameter is monitored to prevent the APU from overheating during operation?
• On the MAX aft overhead panel, REVERSER LIMITED lights illuminated in flight indicate?
• What could happen if the APU experiences a fault while operating under lean fuel conditions?
• Which condition will cause ignition to both igniters when ignition L/R is selected?
• How is APU oil cooled and why is oil cooling important?
• In soft alternate mode, which indicators are visible on the engine panel?
• Which conditions are included in the APU auto-shutdown protection?
• With the engine start lever in IDLE and the engine operating, ignition to both igniters occurs when the engine start switch is in which position?
• REVERSER LIMITED lights that illuminate when on the ground indicate?
• When engine flameout is detected by the EEC, which igniters are activated?
• What should be done if external power is available on the ground?
• How should the APU be cooled down after shutdown?
• Which switch position provides ignition to both igniters when the engine is idle and operating?
• If the EEC senses an impending hot start, the digital readout box starts to blink.
• What does an illuminated amber ENGINE CONTROL light on the aft overhead panel indicate?
• During a wet start on the ground with no EGT rise, what does the EEC do after 15 seconds?
• On the MAX, which statement about the APU DOOR light when the APU has been shut down is true?
• What electrical output is commonly provided by an aircraft APU during ground operations?
• With the ignition select switch in IGN L or IGN R, placing the ENGINE START switch to FLT provides ignition to which igniters?
• How does the APU contribute to cross-bleed starting of other engines?
• What are typical audible/visual indicators that the APU is running or starting?
• A red N2 RPM indication alerts the pilot to?
• What are common reasons for APU auto shutdown during flight?
• What role does the APU play in engine starting on the ground for certain aircraft?
• With engine start switches in FLT and engine start levers in IDLE, ignition is provided to which igniters?
• In the described condition, what does placing the engine start switch in FLT provide?
• Which indicator shows that one or more thrust reverser sleeves are not in the commanded state?
• Which of the following is NOT typically included in APU prestart checks?
• How is APU oil level checked and why is oil quality important?
• The APU cooling air source is drawn from which location?
• What maintenance actions are typically performed on an APU to ensure reliability?
• What are common APU abnormal conditions and their typical symptoms?
• Which statement best describes cross-bleed starting with an APU?
• What is the primary purpose of the APU's electrical generator within an aircraft system?
• The EEC alternates between control channels with each engine start attempt.
• The EEC comprises how many control channels?
• What does the blue MAINT light illuminate on the APU panel?
• What does an illuminated amber REVERSER light on the aft overhead panel indicate?
• What combination must occur for the engine fuel shutoff valve to open besides moving the start lever to IDLE?
• What is the significance of APU EGT in diagnosing APU health?
• A steady OIL FILTER BYPASS alert indicates which condition?
• What does the MAX APU DOOR light indicate when the APU is shut down?
• Bleed air is described as what, and what safety considerations apply to its use from the APU?
• How do you achieve maximum reverse thrust?
• Under what conditions should bleed air isolation valves be used to mitigate a leak?
• In flight, what does the APU DOOR light indicate when illuminated?
• With the engine start lever in IDLE and the engine operating, ignition to the selected igniter only occurs when the engine start switch is in which position?
• Which statement is true about redline overspeed protection in alternate modes?
• The REVERSER COMMAND illuminates when?
• How might ambient temperature affect APU starting and operation?
• Which steps are included in an APU fuel system check?
• What does a green REV displayed above the N1 gauges on the center instrument panel indicate?
• What testing would you perform to verify APU shutdown after a misbehavior?
• With the start selector switch OFF, auto-relight capability activates both igniters when the EEC detects an engine flameout.
• The white box surrounding the digital EGT readout flashes when the EEC senses a condition that may lead to a hot start.
• During APU start, what condition is assessed by permissives before the start command is issued?
• With the ENGINE START switch in CONT and IGN L selected, which igniter is used?
• During a normal NG start, at approximately what N2 speed is power removed from the solenoid holding the engine start switch in GND?
• What are the two alternate modes of the EEC?
• Explain why APU power management must coordinate with ECS and anti-ice systems.
• When is it inappropriate to operate the APU in flight or on the ground?
• During ground starts on the B737-800, what does the EEC monitor?
• With the engine start switch in the GRD position, moving the engine start lever to IDLE provides ignition to which igniter during a ground start?
• What safety actions are required if APU fire is detected on the ground?
• What constitutes a hot start of an APU and how is it mitigated?
• Which indicator on the aft overhead panel indicates the auto-restow circuit has been activated?
• On the engine panel aft overhead, the indicators ON and ALTN are visible when the EEC has automatically changed to which mode?
• An amber REV indication above the N1 RPM readout indicates what status?
• In CUTOFF, the engine start levers close which valves?
• If bleed air management is not coordinated with ECS and anti-ice systems, what could be a consequence?
• What is the difference between pre-oil and post-run oil checks?
• Why is an APU intake/exhaust area restricted during operation?
• What does a green REV indication above the N1 RPM readout mean?
• Why is it important to observe a cooldown period after APU shutdown?
• What electrical frequency is commonly used for aircraft electrical systems powered by the APU on the ground?
• The right igniter is powered by which bus?
• What does an amber OVERSPEED light on the APU panel indicate?
• Which statement best describes a normal indication that an APU is ready to supply bleed air or electrical power during standard ground operations?
• Which indicator on the aft overhead panel indicates a failure in synchronization shaft lock security?
• A red N2 RPM indication alerts the pilot to?
• Which systems are commonly fed by APU bleed air in a typical commercial transport aircraft?
• What is cross-bleed starting and when might it be used?
• If foreign object debris is found near the APU exhaust, what is the appropriate immediate action?
• Thrust reverser deployment requires which condition?