Collection of past Orals Flashcards
What happens if a power generating source fails?
Bus ties automatically connect to provide no system degradation
Can a single pack provide adequate temp control and pressurization?
Yes: up to FL310
What monitors and controls the IDG’s?
Each has a generator control unit (GCU)
Where are the Primary Ejector Pumps located?
In the collector tanks
How many different ways can fuel be supplied to the APU?
- DC Fuel Pump (tank 2)
- AC Fuel Pump (tank 2)
- Tank 2 ejector pump
- Tank 1 ejector pump via X-Feed
- Tank 1 AC Fuel Pump via X-Feed
Will the APU automatically shutdown if speed and acceleration rate isn’t reached in the starting cycle time?
Yes
Explain what happens in Hyd System 2 that allows us to safely conduct a single engine taxi with only Engine 1 operating?
If in “AUTO” (and only engine 1 is operating) upon releasing the parking brake ACMP 2 will activate to provide hyd power for nose wheel steering and the inboard brakes.
What happens if smoke is detected in the recirculation bay?
- Both recirc fans deactivate
- Cargo recirc fan deactivates
- Cargo Outflow Valve closes
What is min. airspeed for the RAT?
What happens if speed drops below that value?
130kts or else Load shedding occurs below this speed
If “OFF” is selected on the ground at what point will the anti-ice system become automatic?
1700 ft. AGL
or
2 minutes after takeoff (whichever happens first)
What is an SPDA?
An electrical load-mgmt unit powered by the ICC’s that distributes electrical loads to aircraft systems according to distribution logic.
What sources are used for aircraft anti-icing and de-icing?
- Bleed air heat
- Electric heat
What uses electric heat for ice protection?
- Pitot-static system
- Windshields
- Water lines
- Pressurization static port
What uses bleed air for ice protection?
Engine lips
3 outboard slats
What airplane systems have fire detection and protection?
- Engines
- APU
- Cargo Compartments
- Lavatories
What model PowerPlant is on our Ejet?
General Electric CF34-8E5, High-Bypass, Dual Rotor turbofan
Describe N2 spool?
10-stage compressor (gas generator)
2-stage HP turbine
What is the purpose of the scavenge pumps?
Maintains fuel level in the collector box
When will the “FUEL 1(2) LO LEVEL” EICAS be presented?
660 lb. of fuel remaining in the associated tank
What is the purpose of the DC GPU receptacle?
For APU start when BATT 2 is either:
Less than 22.5 VDC
or
Colder than -20 degrees
Describe the Engine and APU fire detection system?
Engine: 8 pneumatic fire detectors (2 loops) per engine
APU: 2 pneumatic fire detectors (2 loops)
What does the RAT power?
AC ESS BUSSES
Which powers:
- AC STBY BUS
- TRU ESS: directly powering DC ESS BUS 3 (which powers DC ESS BUS 1 and 2 through ETC 1 and 2)
What components power the DC system?
2 NiCad batteries
3 Transformer Rectifier Units (TRU)
DC GPU receptacle
What components are protected from Ice and Rain?
- Engine inlets
- Wing leading edge
- Smart probes
- Windshields
- Water and Waste drain systems
What happens when a cargo extinguishing button is pushed and smoke has been detected?
- High-rate bottle discharges immediately
- Low-rate bottle discharges after 1 minute if the airplane is in flight
- if airplane is on the ground (WOW) the Low-Rate bottle will not automatically discharge
What manages the electrical system?
4 Integrated Control Centers (ICC’s)
2 Secondary Power Distribution Assemblies (SPDA’s)
Describe in detail the normal engine start sequence?
N2 parameters
- 7%: Ignition
- 20%: Fuel Flow
- 20% + 5 seconds: Light Off
- 50%: IGN Cutoff
- 50%: Starter Cutout
When will the crossbleed valve automatically open?
- Only one side bleed source is available
- Eng 2 start in the air
- Eng 1 start in the air (if APU is not avail)
What is the primary purpose of the AC generators?
To power the AC busses and AC ESS Bus which:
Power the 3 Transformer Rectifier Units (TRU’s) 1 2 and ESS
Can a single bleed source power both packs?
Yes: through the crossbleed valve
How many Hyd. systems are on the airplane?
3 independent systems
Hyd 1, Hyd 2 and Hyd 3
How many hyd pumps are on the airplane?
6 total:
2 Eng driven pumps
4 AC motor pumps
What charges the batteries?
Any AC power source
What is the primary use for APU bleed air?
- ECS on the ground
- Engine starting on the ground
- Electrical source
During flight can the low-rate bottle be discharged before the minute is up?
Yes by pushing the extinguishing button again.
What is the primary purpose of Hyd sys 3?
Back-up for the Flight Controls
Is the ice protection system automatic?
Yes under normal conditions
What happens if there is a single bleed source failure?
The crossbleed automatically opens
How do you shutdown the APU immediately?
-APU emergency stop button -No 1-minute cool down period
What is the purpose of the Hyd system 3 accumulator?
Temporarily provides hydraulics to the flight controls during an electrical emergency. (from the beginning of RAT deployment until AC ESS Bus powers the AC pump 3A)
Can cargo extinguishing be used if no smoke is detected?
Yes. The high rate bottle extinguishing button must be pushed twice: -once to arm the bottle and once to discharge the bottle. -The low-rate bottle automatically discharges after one minute if in flight.
Describe N1 spool?
-Single-stage fan -4-stage LP turbine
How many ice detectors must be working to have icing detection?
One There are two for redundancy
How does the IDG maintain a stable power output?
A constant speed drive (CSD) attaches the IDG to the accessory gear box
What cools the pre-cooler?
-On Ground: N1 fan -In Flight: N1 fan or Ram air
How do you know a GPU is connected and ready to provide electricity?
-GPU button displays AVAIL -GPU icon displayed on synoptic page -Once GPU button pushed in “IN USE” is displayed
Where is fuel tank temp taken?
Left wing tank (-40 C min)
What events will cause an automatic shutdown of the APU IN FLIGHT?
-Overspeed -Underspeed -FADEC critical fault
When are ECS packs recovered?
Thrust Levers NOT at MAX and Airplane is 500 AFE with both engs operating -Airplane is >9700 ft. MSL with one eng operating
What is the purpose of the DCMP?
Used for APU or eng start if AC power or the ACMP is not available.
When does the RAT automatically deploy?
If both AC buses lose power inflight (electrical emergency)
What is normal pressure for any engine operation?
about 45 psi
How many networks make up the electrical system on the airplane? Why?
-2 independent networks -Redundancy and fault isolation
If “ALL” is selected on the ground at what point will the anti-ice system become automatic?
1700 ft. AGL or 5 minutes after takeoff (whichever happens first)
What is the fuel source for the APU?
-Right fuel tank -Left fuel tank through the Crossfeed valve
What happens if the APU EMER STOP button is pushed after a fire has been detected?
-APU shuts off immediately without a 1-minute cool-down -APU fuel SOV closes -APU FIRE EXTG button illuminates
What is the purpose of the forward cargo compartment recirculation fan shutting off and the ventilation outflow valve closing when smoke is detected?
-Prevents oxygen from entering the compartment -Prevents Halon agent from escaping into the aircraft’s cabin
If an IDG is manually disconnected can it be reconnected by the flight crew?
No. This is a maintenance function
What compressor stage is bleed air tapped for anti-icing operations?
10th High stage valve (HSV)
Can the APU shutdown be cancelled?
Yes: by moving the START switch back to “ON” before the 1-minute cool down is over.
What is the Normal AC Electrical Priority?
Onside (IDG) Inside (APU) Outside (GPU) Cross-Side (Opposite IDG)
What events will cause an automatic shutdown of the APU on the GROUND?
FOULFO -FADEC critical fault -Overspeed -Underspeed -Low oil pressure -Fire -Overheat
What does the overheat detection system (ODS) observe?
-Eengine bleeds and packs -APU Bleed -Plumbing For the wing & Eng anti-icing systems
What happens if a channel fails in the AMS controller?
The remaining channel is able to control the entire AMS.
Will the APU automatically shut down if a fire is detected?
Only on the ground
What fuel pump is used for APU start?
-Batteries “ON” only DC fuel pump in right tank -AC powered airplane ACMP 2 -Right engine running Ejector fuel pump
How are the engines and APU protected from fire?
-Engines 2 Halon fire bottles -APU 1 Halon fire bottle dedicated to the APU only
What’s on DC Hot Bus 1?
-Eng 1A/2A Fire Extinguisher -Eng Fuel Shutoff Valve 1 -Hyd Shutoff Valve 1-Eng 1 oil level indication -Courtesy/Service Lights -DC Ceiling Lights
What is the min battery voltage to close the battery bus-ties?
18 volts
In manual mode will the cabin depressurize on landing?
No
Will the APU fire extinguisher automatically discharge?
No
What will happen if batteries are turned OFF during the 1-minute cool down period?
The APU will shut down immediately
What is on the AC STANDBY BUS?
Eng exciters 1A and 2A
What happens if the wiper is operated on a dry windshield?
-The wiper will stop -To reset wiper move switch to “OFF”
How many igniters activate for engine start?
-Ground…1 igniter (switch in AUTO) -Flight…2 igniters (switch in AUTO)
Can one bottle be used for one compartment and the other bottle for the other compartment? (cargo compartment)
No. Only one compartment may be selected (FWD or AFT)
When will the PTU automatically activate?
During T/O and LDG with flaps >0 IF -Eng 2 fails OR -Eng Driven Pump 2 fails
Can engine bleed air flow-back to the APU?
No. A check valve prevents flow-back.
What kind of APU is on the aircraft?
Sundstrand APS 2300
If the airplane is using the GPU and the APU is started what should the pilot be sure to do?
Remember to deselect the GPU button before the next GPU connection
How long will the aircraft’s batteries last with no recharging?
Approx. 10 minutes
What are the basic components of the hyd systems?
-Reservoir -Pumps -Accumulators
What is bleed air used for?
-ECS (heating and cooling) -Engine start -Engine and wing anti-icing -Water pressurization
Can the APU replace a failed IDG
Yes
In an electrical emergency can Hyd sys 3 power requirements possibly overload the RAT?
No. A flow limiter valve is used to reduce hyd fluid flow and limits Hyd pump electrical power draw to prevent a RAT stall.
Where is the external ground source pneumatic panel located?
Lower fairing between the wings
When is the RAT icon displayed on the electrical synoptic page?
When the RAT is deployed
What is the only way to close the engine fuel SOV?
Pull the associated engine fire extinguishing handle
How does the failure of one of the two power sources affect the windshield heating system?
-On ground inhibited -in flight Left side is heated (right side heats if Left has failed)
What provides air for the AMS?
-Engine bleeds -APU Bleed -External pneumatic source
Are the cockpit and cabin protected from fire?
-Yes -Cockpit 1 hand-held Halon fire extinguisher -Cabin 3 hand-held Halon fire extinguishers (1 fwd and 2 aft) -Cabin 1 hand-held Water fire extinguisher
Can the igniters be turned off during flight?
The switch may be moved to the off position but the FADEC DISREGARDS the COMMAND-the off position is Used For dry-motoring on the ground only
What is an indication of an APU fire?
-Fire Bell -Red stripe in the EMER STOP button -APU Fire is displayed on the EICAS
If there a total loss of power during the gap between RAT deployment and when it produces useful electrical power?
No. Batteries supply power to the DC ESS Busses and AC Standby Bus
What is the difference between the high-rate bottle and the low-rate bottle? (cargo compartment)
-High-rate bottle saturates the compartment immediately -Low-rate bottle maintains saturation over 60 mins
Can one IDG supply the entire electrical system?
Yes
What is the Primary ejector pump?
-Venturi pump (no moving parts, no electrical power) -Powered by motive flow only
The FADEC will prevent fuel flow during ground start until ITT is at or below_____?
120*C
What happens when the ignition switch is selected to OVRD?
Activates both igniters ON THE GROUND OR IN FLIGHT
What battery is used for the APU start?
-BATT 2 powers the APU start bus -BATT 1 powers the FADEC and EICAS for monitoring
What powers the Refueling and Defueling panel?
Powered by BATT 2 or DC Buses
Can the pilot override the automatic system?
Yes
What is external pneumatic air used for?
-ECS on the ground -Engine start on the ground
What does the cyan N1 tick represent?
Max N1 for selected engine thrust mode
What is the ratio of fresh air to recirculated air?
52% FRESH air to 48% RECIRCULATED air
What keeps the FWD & CTR E-BAY’s cool?
3 fans each pull air from cabin to bay
What keeps the AFT E-BAY cool?
Natural air-flow from cabin to bay
When is the Emergency Ram Air Ventilation activated?
-Both packs commanded or failed OFF below 25000 ft. (via left side and electronically controlled) -Ram air pressure greater than cabin pressure (differential pressure via right side) via one-way check valve No electrical power required
If engine and APU bleed air are both avail simultaneously which has priority?
APU has priority if:-Aircraft is on the ground-Wheel speed
What is the purpose of the pre-cooler?
Cools the bleed air coming from the engine to the AMS
What powers the Ram Air Turbine (RAT)?
Airflow turns the RAT propeller which spins the generator turbine inside.
How many brake applications does the hyd accumulator provide?
About 6 applications
List the things that the air in the Air Mgmt System (AMS) used for?
-ECS (heating and cooling) -Engine Start-Pressurization -Eng and Wing Anti-ice -Water pressure -Hot air leak detection
How long will the low-rate bottle remain active in the compartment? (cargo compartment)
60 minutes
Where is bleed air tapped from the engines?
-6th and 10th stage compressors (Eng Bleed valve and High stage valve respectively) -System alternates between valves to regulate an adequate and safe pressure
When do the smart probes heat?
When an engine is running
When are the recirculation fans commanded off?
-Cockpit switch -Smoke detected in the recirc bay -DUMP button is pressed -Respective pack is commanded “OFF”
What kind of APU? Rating?
Sundstrand APS 2300 115VAC 400Hz 40KVA
How long will the de-icing system remain on after icing is no longer detected?
5 minutes
What are SPDA’s and what do they do?
-Secondary Power Distribution Assemblies -Electrical load mgmt unit -Receives power from ICC’s -Distributes power according to system logic
What does the “TIMER” selection on the windshield wiper switch do?
Activates the associated wiper in 8-second intervals
What exactly does the ATTCS do?
-Provides max thrust (RSV) when thrust levers TOGA AND -Difference between N1 values >15% OR -One engine failure during takeoff or go-around OR -Windshear detection
What is the purpose of the accumulator?
-Maintains constant pressure by covering transient demands -Helps to avoid pump cavitation
Which pumps provide motive flow to the ejector pumps and are the primary fuel source to the engine?
The engine driven pumps
How many ECS packs are on the airplane? What provides air for the packs?
-2 independent packs (left & right) -Each engine provides bleed air to its’s respective pack
What systems use hydraulic power?
-Flight controls -Spoilers -Landing gear -Nose wheel steering -Wheel brakes -Thrust reversers
What controls the APU?
A dedicated FADEC
How is single eng taxi possible if nose wheel steering is on Hyd system 2?
Releasing the parking brake automatically activates AC Hyd pump 2
How many channels on the Cabin Pressure Control (CPC)?
2 channels (one active and one in standby mode)
What happens to the forward cargo compartment in the event smoke is detected?
-Recirculation fan shuts off -Ventilation outflow valve Closes
Can hydraulic fluid be transferred between each system?
No
What does selecting “ALL” on the MCDU provide?
-Engine anti-ice “ON” when engines are running -Wing anti-ice “ON” at 40 kts wheel speed
How many channels does each FADEC have?
Each FADEC has 2 channels:-1 Active-1 Standby
What does moving the APU start switch to “OFF” do?
-Initiates normal APU shutdown -1-minute cool down -No pneumatics (electrics only for 1 minute)
What is the purpose of the ACMP?
-Back-up pump in case Primary ejector pump fails -Engine start -Crossfeed operations
Why are Hyd AC motor pumps 3A and 3B switch positions different? ““ON”” & ““AUTO”” respectively?”
-Hyd AC motor pump 3A is primary and has no automation-Hyd AC motor pump 3B is a back-up and automatically activates if AC motor pump 3A fails
What are some important items controlled by Hyd system 2?
-Landing gear -Nose wheel steering -Inboard brakes
How is ice detected in flight?
-2 ice detectors -Vibrating sensor element changes frequency when ice builds up around it -One ice is detected sensor element heats ice melts the normal vibration resumes and the heating process stops -Cycle repeats as ice rebuilds on the probes
What are some things that will close the ECS packs?
-Any Eng start if APU is the Bleed source -Eng start on the ground -Respective Bleed system duct leak -Bleed air source not AVAIL For the pack -Thrust Levers set to MAX on Takeoff -REF anti-ice set to ALL on Takeoff -REF ECS set to off on MCDU (APU is off)
What controls the ATTCS?
Controlled by FADEC
What is the bleed system priority in flight?
-Onside engine -Opposite side engine -APU (if AVAIL)
What types of fuel pumps are in each wing?
-Primary ejector pump -ACMP -DCMP (right tank only)-3 scavenge ejector pumps
Where does the CPC get Landing field elevation?
FMS or can be manually selected
What is an ICC?
An electrical control device which provides power distribution and protection for electrical loads.
What is the min battery temp for APU start?
-20 degrees Celsius
What is the surge/vent tank?
Collects fuel during wing-down maneuvers and returns it to the main tanks Once the wings are level, equalizes tank pressure with atmosphere in flight and during refueling
How can the low-rate bottle be discharged if the airplane is on the ground (WOW)?
The extinguishing button must be pushed again.
When will the RAT deploy?
-Automatically deploys if AC busses are not powered or -Manually by pilot
What does the N1 moving arc represent?
value requested based on TLA (Thrust Lever Angle)
What happens if the APU EMER STOP button is not pushed after a fire has been detected?
After one minute the APU FIRE EXTG button illuminates
What is the power source for engine and APU fire detection and protection?
-Engine Detection DC ESS -Engine Protection HOT BATT- -APU Detection DC ESS -APU Protection DC ESS
What is the purpose of the TRU’s?
To convert 115VAC to 28VDC
How many fuel tanks does the airplane have?
2 integral tanks
What is the purpose of the fuel collector box?
-Keeps fuel pumps submerged -Ensures constant fuel flow to respective engine
How should the aircraft be configured for de-icing?
-Bleeds……………….OFF -Stab Trim…………..Full Nose down -Flaps………………….UP -Engines & APU…ON or OFF
Is there a test for the anti-ice system?
Yes but maintenance performs this test
What controls the engine?
A two channel FADEC (One channel is active and the other channel remains in standby as a backup)
What does it mean when the GPU AVAIL light is illuminated in the cockpit and the outside GPU panel displays IN USE outside?
The ground service bus is being powered by the GPU even though cockpit GPU button has not been pushed in.
What’s on DC Hot Bus 2?
-Eng 1B/2B Fire Extinguisher -Eng Fuel Shutoff Valve 2 -Hyd Shutoff Valve 2 -Eng 2 oil level indication -CMC (Central Maint. Computer) -Panel Refuel -Water and Waste System
What is the RAT rated at?
115VAC 400Hz 15KVA
How many AMS controllers are installed?
One controller with 2 channels which control the respective onside system.
How many igniters per engine?
2
What components power the AC system?
-2 Integrated Drive Generators (IDG) -Auxilliary Power Unit (APU) -Inverter-Ram Air Turbine (RAT) -AC GPU receptacle
Describe the APU
-Constant speed -Single-stage impeller with a 2-stage axial-flow turbine -Independent oil system
Is only one FADEC channel used every flight?
No. They automatically alternate with each engine start.
How many accumulators does Hyd system 1 and 2 have?
2 accumulators per system (One for shock absorption, the other for emergency parking brake use)
What does the green N1 tick represent?
Max N1 allowed for current thrust rating and current operating conditions
What is the purpose of the Fuel Crossfeed?
-Allows fuel to both engines from one tank -Used to correct fuel imbalance
How long after deployment before the RAT will supply power?
Approx. 8 seconds
Can both engine fire bottles be used for one engine if needed?
Yes
How many extinguishing bottles are installed for the cargo compartments?
-2 bottles used for both compartments -1 high-rate bottle and 1 low-rate bottle
How many engine driven generators? Rating?
2 IDG’s (Integrated Drive Generators) 115 VAC 400Hz 40KVA
What happens when the crossfeed switch is selected to LOW 1?
-Crossfeed valve is opened -Commands the ACMP 2 to “ON” to provide fuel from the right tank to both engines
Can fuel be transferred from tank-to-tank or be dumped overboard?
No
Can the cabin altitude be raised higher than 12400 ft.?
-Yes by using manual mode -Cabin altitude will rise due to natural leak
What color is the LFE on the EICAS?
-Green FMS input-Cyan Manual input (an “M” will be in front of LFE)
What is the ABORT mode?
Cabin is scheduled back to the takeoff altitude if: -Airplane stops climbing AND -Begins a descent AND -Airplane has not climbed >5000 ft AFE or >10000 ft MSL
If an engine fails does the opposite wing and engine receive ice protection?
-The cross-bleed valve opens, provides A/I protection for both wings -The failed engine does not receive Engine Cowl A/I
What is a PTU?
-Power Transfer Unit -Mechanical pump that uses Hyd sys 1 power to provide Hyd sys 2 pressure
What is the purpose of the inverter?
Converts 28VDC from the batteries to 115VAC to power the AC STANDBY BUS when an AC source is not available.
What pump is used once an engine is started?
Associated primary ejector pump
How many fuel pumps do we have on the EJET?
-2 eng driven -2 ejector -6 scavenge -2 AC electric -1 DC electric
Which if any Hyd AC motor pump will function if the RAT is the only power source?
Hyd AC motor pump 3A only
How is each FADEC powered?
-ESS powered below 50% N2 -PMA powered above 50% N2
What happens when the dump button is pressed?
-Commands both ECS packs OFF -Opens outflow valve and raises the cabin to 12400 ft. at a rate of 2000 fpm
How is bleed air directed for pneumatic anti-ice?
-Engines are independent -Wings from Onside Bleed
What are ICC’s? What do they do?
-Integrated Control Center -4 installed in various electronic bays -Collects and confirm power is safe -Sends power to SPDA’s
Can the flight crew reset the ICC and SPDA remote electronic CB’s?
-ICC CB’s can only be reset by Maintenance -SPDA CB’s can be reset bia the MCDU
Can the APU be used to provide bleed air for de-icing?
No.
What is the max thrust produced by the CF34-8E5?
Max Thrust 14200 lbs.
What happens when an engine fire handle is pulled?
-Closes engine Fuel SOV -Closes engine Hydraulic SOV -Closes engine Bleed SOV
How are the lavs protected from fire?
Heat-sensitive extinguishers in the lav waste bins (auto discharge at predetermined temp)
What events automatically activate an AC Hyd pump INFLIGHT?
-Engine driven pump failure OR -Flaps selected to any position greater than 0
What is the primary purpose of the PTU?
To allow landing gear retraction in the event of an Eng 2 or Eng Driven Pump 2 failure.
Where does the CPCS get cruise flight level & landing elevation from?
FMS before Takeoff or CPCS calculates using ambient pressure-LFE may be Manually imputted
Do both loops in the AMS overheat detection system have to function in order to detect an overheat condition?
Yes but if one fails the other will work alone to detect an overheat.
What happens if while on the GPU you then start an engine?
The respective IDG takes priority over the GPU and will now power it’s side of the network while the GPU continues to power the other side.
What will cause the amber IDG light on the overhead panel to illuminate?
High oil temperature-Low oil pressure
Can the APU be started after a critical fault?
No
What events automatically activate an AC Hyd pump on the GROUND?
-Flaps selected to any position greater than 0 AND -Thrust levers set to T/O thrust OR groundspeed >50 kts
During an electrical emergency what provides Hyd pressure to the flight controls until the RAT comes online?
-Hyd system 3 accumulator -After 8 seconds the RAT will power Hyd AC motor pump 3A
What bus is powered by the RAT?
AC ESS (Directly powers AC ESS which powers TRU ESS, which powers DC ESS BUS 3 which powers DC ESS BUS 1 and 2 through ETC 1 and 2)
How many smoke detectors are installed in the cargo compartments?
-3 detectors in the FWD compartment -2 detectors in the AFT compartment
