Tech info Flybe Q400 Flashcards
How many emergency exits are there?
There are 5 Emergency Exits – including the Emergency Escape Hatch.
How many doors have pressurised seals?
Only two Doors have pressurised seals - the Main Passenger Door and the Rear Baggage
Does the Q400 have escape slides?
The Q400 doorsills are at the maximum height allowed without Escape Slides being fitted.
What doors have ditching dams fitted to them?
Ditching Dams are fitted to the two Forward Exits only.
How many batteries and what type?
3 x Nicad batteries
How many TRU’s are there?
2
What are the purposes of the 3 batteries?
1 main, 1 aux and 1 standby
What are the following specs of the batteries?
Main / Aux / Standby: Voltage and AH
Main / Aux: 24V 40AH
Standby: 24V 17AH
What is an EPCU?
Electrical Power Control Unit (EPCU) accounts for individual power source or bus failures by the automatic opening and closing of Bus Tie Contacts.
What voltage do the TRU’s supply?
28V DC
What voltage do the generators supply?
115V AC
What services is on the hot battery busbar?
- Fire Extinguisher Squibs
- External Refuelling Panel and associated Shut-off Valves
- Hydraulic / Fuel Shut-off Valves
- Boarding Lights
- Flight Deck Emergency Dome Light
- Clock
- PA – (when activated by the Emergency Light Switch)
What is the purpose of condition levers? (2)
First is as a fuel shut off.
Second they control propeller RPM.
There are 5 positions for the CL’s:
- Fuel off
- Start/feather
- 850rpm
- 900rpm
- 1020rpm
How long do the liminous strips stay lit for and how long does the cabin stay lit for in an emergency?
Floor-level guidance is provided by luminous strips, which stay bright for 20 minutes following 20 minutes of cabin light illumination.
What is the maximum theoretical fuel load?
The Maximum theoretical useable fuel load is 5,318 kg. Practically - due to the limitations of pressure refuelling, approx. 5200kg is more likely.
What is the maximum fuel imbalance limit?
272 kg
Can it be fuelled over wing if pressure refuelling is not available?
Yes.
What refuelling pressures are required for refuelling?
Refuelling Pressures 20 - 50 PSI
What engines does this aircraft have?
Pratt & Whitney PW150A turboprop engines
Propellor facts:
- Number of blades?
- Constant speed?
- Variable pitch?
- Manufacturer and model number?
- six bladed
- constant speed
- variable pitch
- fully feathering Dowty R408 propeller
How much shaft horse power from each engine?
The powerplant develops 4,580 Shaft Horse Power (SHP) under normal takeoff conditions. An automatic uptrim allows either engine, to develop a maximum takeoff power of 5071 SHP, for a brief period of time, if an engine failure occurs during takeoff.
How is propeller RPM, manual propeller feathering, and fuel on/off control for engine start and shutdown controlled?
Condition levers
Does the Pratt and Whitney PW150A engines have FADEC?
Yes
How many shafts does the PW150A engine have?
3
- A Low Pressure Axial Compressor and Low Pressure Turbine mounted on the middle shaft.
- A High Pressure Centrifugal Compressor and High Pressure Turbine mounted on the outer shaft.
- A Power Turbine mounted on the inner shaft that extends forward to drive the reduction gearbox.
How does the engine work?
The three shafts rotate independently, with the LP and HP shafts contra-rotating to reduce gyro effect. The airflow enters the LP Compressor and then flows into the HP Compressor where it is further compressed and turned through 90 degrees. The compressed air enters the Combustion Chamber where it is mixed with fuel sprayed into the Chamber through 12 nozzles. Two igniter plugs, controlled by FADEC, ignite the mixture. The resulting high energy exhaust flows - through the HP Turbine, driving the HP Compressor - through the LP Turbine, driving the LP Compressor and then through the 2-stage Power Turbine, which drives the Propeller, through the Reduction Gearbox.
What does the drive shaft drive in the accessory gearbox?
- Oil Pressure and Scavenge Pumps
- High Pressure Fuel Pump (Integral within FMU)
- DC Starter / Generator
- Permanent Magnet Alternator (PMA)
What is the PMA?
The PMA provides an independent source of electrical power to FADEC; Essential Busbar Power backs this up for Engine Start (when the PMA is not energised) and in the event of PMA failure.
What does the reduction gearbox power?
- Pitch Control Unit (PCU) OIL Pump
- Propeller Overspeed Governor
- Main Hydraulic Pump
- 115v AC Variable Frequency Generators
What would FADEC do in the event of an engine flame out?
In the event of an Engine Flame-out, FADEC would activate both Igniters on the failed Engine to attempt a Hot Relight (Auto Relight Function). If this were successful, the first indications would be an increasing ITT, followed by increasing NH. This should happen very quickly.
What is an automatic uptrim?
An automatic uptrim allows either engine, to develop a maximum takeoff power of 5071 SHP (+10%), for a brief period of time, if an engine failure occurs during takeoff.
How does FADEC prevent engine overspeed?
The Engine has an independent Overspeed Protection (O/S) Circuit built into FADEC, which can cut off Fuel Flow using the Fuel Shut-off Solenoid. This would occur if the NH exceeded 106%. In order to exercise the system, the O/S Protection Circuit is used to shut off fuel on every normal engine shutdown
How is oil temperature controlled?
It is air cooled by a heat exchanger under the cowling.
How long after shutdown must the oil be checked?
Gauge is behind a panel on the Left side of the Engine. The Oil Level must be checked within 15-30 minutes of engine shutdown.
What engine is started first and why?
The #2 Engine (right) is normally started first as this pressurises the Emergency Brake system. This is achieved even though the #2 Main Hydraulic Pump (driven from reduction gearbox) is operating well below its normal operating speed. The Ignition Switches will have been switched ON during the First Flight safety Checks.
What three peramiters would cause the FADEC to abort the start?
- The engine does not light up within 16 seconds of Fuel Flow commencing.
- 920’C ITT is exceeded.
- NH does not reach 50% within 70 seconds.
What is the propellor made from?
Spars?
Filled with?
Carbon fibre spars filled with polyurethane foam.
The Propeller Blades are mainly of Composite Structure with electrically heated De-ice Mats and Nickel Erosion Sheaths.
What system changes the pitch of the propellor and what medium is used?
Propeller Blade Angle is controlled by a dual-channel, Propeller Electronic Control Unit (PEC). The PEC sends commands to the Pitch Control Unit (PCU), which manages the flow of high-pressure oil within the propeller hub to adjust blade angle.
How does the alternate feather pump work?
The 28v DC Alternate Feather Pump has its own reservoir topped up by main engine oil line supply, within the Reduction Gearbox and operates a back-up Feather Valve in the PCU. It provides a secondary source of pressurised oil for feathering the propeller (and for unfeathering, when required for maintenance).
Is there an unfeathering function in flight?
There is no unfeathering function in flight. The Feather Pump Selector Switchlights are on the Propeller Control Panel; a green bar lights up below the FTHR legend when the Pump is running. The pump can be selected on manually or automatically by PEC AutoFeather action. The pump will run for 30 seconds when the feather pump relay will be de-energised and the pump will stop.
What is the function of the counterweights on the propellor hub?
Counterweights are fitted to the Propeller Hub to drive the propeller blades towards the Feather Position (for low drag (left)) in the event of a loss of Hydraulic Pitch Change Pressure.
If this failure occurred in the Reverse Range, the Counterweights could drive the blades towards full reverse pitch.
What is the maximum propellor speed? What are the two stages of protection?
The maximum Propeller speed of 1020 RPM is controlled by the PEC / PCU.
The first is provided by the Overspeed Governor, which cuts off the supply of high-pressure oil to the PCU if the PRPM exceeds 1071.
The second stage of protection is provided by FADEC, which, in the event that the O/S Governor fails to control the PRPM, will command the FMU to reduce fuel flow to the engine at approximately 1173 PRPM (1170 indicated). Normal fuel flow is resumed when the overspeed condition is removed.
Describe the beta range and how it operates?
In the Beta Range, FADEC senses Power Lever Position and commands the PEC to generate the appropriate Blade Angle. FADEC maintains PRPM between 660 and 950 by adjusting fuel flow.
Describe the synchrophase and how it operates?
Syncrophase is automatically provided by the PEC (prop electronic control) when the Condition Levers are set to 850 or 900 RPM;
What 3 things drive the propellor into the fully feathered position when autofeather is activated?
If Auto-feather is activated, the propeller will be driven to the fully feathered position by the PEC, assisted by Counter-weights and by the Alternate Feather Pump.
When does autofeather activate? (3)
Torque < X%
PRPM < X%
Seconds?
Autofeather is activated if the Torque of the affected engine falls below 25% for at least 3 seconds and the PRPM falls below 80% (816 RPM).
What is an AUPC?
The AUPC (Automatic Underspeed Protection Unit) protects against failure conditions, which drive the propeller towards a coarse blade angle. It would be over-ridden by Autofeather and Alternate Feather operation.
What is a reduced NP approach?
This function allows a quieter approach for noise abatement and passenger comfort with the protection that, in the event of a go-around, the PRPM will automatically reset to MAX as the Power Levers are advanced through 50% Torque.
What causes a wet start?
A Wet Start may be due to the Ignition Switch being off, or possibly a failure of the ignition system. The Engine Clearing Procedure must be completed if another starting attempt is to be made.
What is a hot start?
The most common reasons for a hot start include insufficient airflow through the compressor, incorrect fuel scheduling and slow engine acceleration. This will be indicated by a high ITT reading and low RPM.
Unless caused by an attempt to start with low battery power, should be investigated, as this is most unusual. An obstruction to the normal airflow into the intake should be considered and investigated before attempting a further start.
How many fire bottles are there and where are they located?
Two Fire Bottles are located in the Left Wing Root and each can be discharged into either engine. Both Fire Bottles are armed when a PULL FUEL/HYD Handle is pulled.
What systems use pneumatics on this aircraft? (4)
The following systems use pneumatics for operation:
- Air conditioning and pressurisation
- Airframe de-icing
- Airstair door seal pressurisation
- Engine oil cooler ejectors
Describe the airconditioning system?
The Air Conditioning Pack is part of the Environmental Control System (ECS). It uses bleed air from the engines or Auxiliary Power Unit (APU) to supply conditioned air to the cabin and flight compartment. The system responds to flight crew commands and compartment temperature controls to supply a comfortable temperature environment for passengers and crew.
Two air cycle machines (ACM), with one dual heat exchanger located in the aft fuselage, cool the bleed air coming from the two engines. This configuration provides the redundancy of two packs while allowing access to a much larger dual heat exchanger during operation with a single ACM.
What parts of the aircraft are pressurised?
The Cabin Pressure Control System keeps a constant cabin pressure during the ground and flight modes. The system controls the cabin altitude and the cabin rate of change.
The pressurised part of the aircraft lies between the Forward Pressure Bulkhead and the Aft Pressure Dome. Both Baggage Compartments are included in the pressurised area.
Where are the ice protection systems?
The anti-icing systems use electrical heating elements to prevent ice formation.
See attached systems.
How do the ice detectors work?
Two Ice Detector Probes are fitted - one on each side of the nose. They function by continuously vibrating a Piezoelectric Diaphragm at the end of a sensor probe. Any ice accretion will change the frequency of vibration and display an ICE DETECTED Message at the bottom of the ED. The Probes are then heated for a short time to remove the accumulated ice and check for further accretion. There are two types fitted to Flybe Q400, both operate in the same way; the most common type is shown for reference.
What are the hydraulic system functions of 1,2,3 and 4?
The No.1 and No.2 hydraulic systems are normally pressurised by a single Engine-Driven Pump (EDP) for each system.
The No. 3 hydraulic is powered by an accumulator that is pressurised by a DC-Motor Driven-Pump (DCMP). If a dual engine failure occurs, where neither EDP or the SPU are available, the DCMP in No.3 hydraulic system provides sufficient hydraulic power to the elevators for pitch control.
The No. 4 system is a manually powered hydraulic system (powered by a Handpump)
What do the amber, green and red gear lights indicate? (3)
Amber Light - The associated Hydraulic Door is not closed
Green Light - The associated Gear is down and locked
Red Light - The associated Gear is not at the position selected
What type of rudder system does the Q400 have and what are the maximum deflection with flaps and no flaps?
The Fore/Trailing Rudder System gives a maximum deflection of +/-18o (Restricted to +/-12o with the Flaps set to 0o due higher speed). The Fore Rudder is deflected directly by a linkage from the Powered Control Units (PCU); the Trailing Rudder is hinged to the Fore Rudder and deflected by linkage to double its angle.
What is an ARCDU?
Audio Radio Control Display Unit and is the main Control Panel for selection of Communication and (non-FMS) Navigation facilities, although ARCDU is fully integrated with FMS.
What is an ADU and an ISI and how many of them are there on the Q400?
Air Data Unit x 2.
Integrated Standby Instrument x 1.
What is an FGCP?
The Flight Guidance Control Panel is used to programme the Flight Director (FD) and make Autopilot (AP) selections. Same as an MCP.
What is ESID?
Engine and Systems Integrated Display
What is the manufacturer and model of the weather radar on the Q400?
HONEYWELL PRIMUS 660 WEATHER RADAR
What type of TCAS are Flybe aircraft fitted with?
Flybe Q400’s are fitted with at least version 7.0 and are being upgraded to 7.1 currently.
What is GPWS Mode 1?
Mode 1 - Excessive Descent Rate (Any Configuration)
What is GPWS Mode 2A?
Mode 2A - Excessive Closure Rate to Terrain - Flaps not in Landing Position.
What is GPWS Mode 2B?
Mode 2B - Excessive Closure to Terrain – Flaps in Landing Position
What is GPWS Mode 3?
Mode 3 - Altitude Loss after Take-off or Go-around
What is GPWS Mode 4A?
Mode 4A - Unsafe Terrain Clearance - Gear UP and Flaps not in a Landing Position
What is GPWS Mode 4B?
Mode 4B - Unsafe Terrain Clearance - Landing Gear DOWN and Flaps not in Landing
What is GPWS Mode 4C?
Mode 4C - Unsafe Terrain Clearance – Gear UP, Flaps not in a Landing Position (Following Take-off or Go-around)
What is GPWS Mode 5?
Mode 5 – Deviation Below Glideslope
What is GPWS Mode 6?
Mode 6 - “MINIMUMS” and Excessive Bank Angle
How does the EGPWS work?
EGPWS works alongside the GPWS and provides additional Terrain and Obstacle information from a Navigation Database to predict Obstacle or Terrain threats and to provide a Terrain Map for pilot situational awareness.
