Systems Q&As Flashcards
What materials are used to construct the engine firewall?
A firewall comprising fire resistant matting and stainless steel cladding on the engine side, separates the engine nacelles from the rest of the structure.
How many flying control trim systems are there?
2
- Elevator trim operated manually using elevator control wheel on centre console or electrically using the stick top trim switch only on left control column.
- Rudder trim operated manually on centre console.
Also multiple fixed trim tabs across aircraft.
What materials are used to construct the flaps?
GFRP/CFRP
Glass/Carbon fibre reinforced plastic
How many settings do the flaps have?
3
Cruise (up) 0deg top light green
Approach (app) 20deg centre light white
Landing (ldg) 42deg lower light white
What is the maximum upward travel of the elevator?
Full deflection 15.5deg
What is the maximum upward travel of the elevator with stick limit actuator engaged?
13 deg
When both power levers advanced beyond ~20% and flap is at LDG
How many switches does the stick limit backstop actuator have?
3
The system uses an electric actuator controlled by two micro switches on the power lever and by the flap selector switch.
At what power setting does the stick limit actuator engage with LDG flap selected?
Approx 20%
What are the flap limitation speeds?
TDI
Vfe APP 137KIAS
Vfe LDG 111KIAS
What type of system is used to operate the landing gear?
The gear is retracted and extended hydraulically
How is the hydraulic pressure provided?
By an electric pump
Does the nose wheel retract rearward or forward?
Forward
Why does the landing gear have 2 limiting speeds?
The retraction speed is slower as it moves in the opposite direction to the airflow and therefore risks damaging the gear and housing if the force is too great.
How are the springs incorporated into the gear system?
Springs help the actuator to extend the gear and when the down-lock hooks engage, hold them in the engaged position.
What prevents inadvertent gear retraction?
Gear held down by down locks and continual supply of hydraulic pressure.
How is the gear extended when a system failure occurs?
The gear will descend under gravity provided the hydraulic return lines are open.
How is the landing gear held up?
Hydraulic pressure
How long does gear extension take?
6-10seconds
What are the gear limitation speeds?
Vldr Retract 156KIAS
Vlde Extend 194KIAS
During retraction, hydraulic pressure on each side of the piston is equal. How does this allow retraction to occur?
Because of the larger surface area on the retraction side, fluid flows from the extension side and the landing gear retracts.
What type of system do the brakes use?
An independent Hydraulic pressure system
Do the co-pilot’s brake pedals link directly to the brake cylinders?
No, they link through the primaries pedals
How is the cockpit heating operated?
2 levers on the centre console
Which engine is used for cabin heating and windscreen defrost?
LH Engine for windscreen defrost
RH Engine for cabin heating
Where is the air inlet located for the ventilation system?
Underside of the inner section of the RH wing through a NACA duct.
How is warm air generated for the heating system?
Hot coolant from the engine cooling system flows through the heat exchangers and heats air drawn in through the engine air intake.
How many nozzles can be operated in the cockpit/cockpit to provide fresh air?
6 overall
2 on L+RHS of main instrument panel
2 on L+RHS of cockpit walls in passenger area
2 on the cabin roof
What engines are fitted to the aircraft?
2 x 4-cylinder, liquid cooled, turbo charged Thielert TAE 125 four stroke diesel engines
What is the max power output?
99kW at 2300rpm at sea level ISA
Is there a maximum continuous power restriction for these engines?
No
What type of system is used to cool the engines?
Liquid cooled with a mix of water and antifreeze
Where is the heat exchanger located for this system?
In the Engine intake of each engine
How is the air pre-heated to aid starting the engine?
When the coolant is cold the valve directs through the bypass circuit straight back to the pump inlet
How many oil systems does engine have?
2
- Engine and CSU
- Gearbox
Do these systems use the same type of oil?
No
Engine = Shell Helix Ultra 5w40 Synthetic API SJ/CF or Aero Shell 10w40
Gearbox = Shell EP 75w90 API GI-4
Where is the gearbox oil inspection panel located?
RHS above engine intake
How many cylinders does each engine have?
4
How many ECUs does each engine have?
2, A and B each
Which ECU is used during normal ops?
A
Where are the ECU swap switches located on the instrument panel? What are the available selections?
LHS of cockpit
ECU Auto or ECU B
When can manual selection of ECU B take place?
Only if automatic switch over fails
What are the functions of the ECU test buttons?
To test the FADEC on ECU A and ECU B respectively
When the Engine Master is selected ON, where is the power supplied to?
- Powers the associated glow plug.
- Displays the appropriate L or R Engine Glow Advisory Alert.
- Opens the associated unfeathering accumulator shut-off valve.
- Energises the engine and propeller control circuits
Where is the alternate air selector located?
Underneath the co-pilots side of the cockpit
Does this supply both engines?
Yes
How many engine system pages are there on the PFD/MFD?
2
Fuel and System
Why don’t we shut the engines off using the fuel selector (off)?
Causes damage to the high pressure fuel pump
What type of propeller installation does the aircraft have?
3-blade constant speed, variable pitch
What materials are used to construct the blades?
Wood composite construction with a stainless steel leading edge
What are the benefits of the wood-composite for blades?
Light weight, reduces rotational inertia and minimises vibration.
What controls the propeller pitch system?
A single-acting constant speed unit (CSU) controls pitch angle via a pitch control unit (PCU).
How is the oil pressure regulated for this system?
By an electrically operated governor valve in the CSU - ultimately controlled by the FADEC
Increasing oil pressure in the CSU system allows finer or coarser pitch?
Allows finer pitch and decreases RPM.
When the engine is running, how much oil pressure is the accumulator filled with?
The same as the CSU. System pressure.
When the engine master is selected to OFF, what happens to oil pressure at the accumulator? How does this happen?
The accumulator shut-off valve closes, trapping oil in the accumulator at system pressure.
What is the purpose of the propeller counterweight?
Produces a centrifugal twisting moment which counteracts the centrifugal twisting moments of the propeller blades towards fine pitch.
What is the minimum propeller speed allowable for feathering to occur?
1300RPM
What is the static RPM range permissible for T/O?
2240-2300
To un-feather the prop, the engine master is selected ON. What happens at the pressure accumulator to allow this to happen?
The accumulator shut-off valve opens to allow pressurised oil to be delivered to the CSU.
What are the approved fuel grades for the aircraft?
JET A-1, JET A, JET Fuel No.3, JP-8 and Diesel.
What is the acceptable temperature range use of JET A-1 fuel?
From -30degC to +75degC (from -22 defF to +167degF)
What is the acceptable temperature range use of diesel fuel?
Engine starting fuel temp…min -5degC (+23degF)
T/O fuel temperature…min +5degC (+41degF)
Max fuel temperature… +75degC (+167degF)
What is the max useable fuel available?
50 US Gal.
196.7 L
What is the max permissible fuel imbalance?
5 US Gal
18.9 L
How many chambers are there is each wing?
3 interconnected chambers
What type of fuel gauging system is used to measure quantity?
2 capacitance-type fuel sensors are fitted in each tank
How is the fuel supplied to the engine cylinders?
There is a fuel crossfeed system which can supply either engine from either tank.
Where is the fuel selector located? How many positions are there?
In the centre console. On/crossfeed/Off
What are the operational restrictions of crossfeed selection?
The aircraft must not be operated in the air with both fuel selectors in the crossfeed position.
Do not take off with either fuel selector set to crossfeed.
What material is used to construct the fuel tank?
Aluminium
What protection does the fuel tank have from high pressure?
The tanks are vented to atmosphere using check and pressure relief valves.
What is the purpose of the check valve?
The check valve allows air to enter the tank.
Why does the aircraft require fuel temp control?
As the engine returns unused fuel to the tanks which has to be cooled before it enters the tank. If the cooling system fails then the increase in temp of the fuel could be catastrophic.
Why is diesel fuel not used at lower temps?
It will freeze
On the fuel temp gauge, what does the yellow range indicate?
-30degC to -22degC and 70degC to 75degC
With the right fuel lever to Crossfeed, which fuel tank is supplying the right engine?
The left tank
How is the bypass of the exhaust gases controlled?
A sensor located in the outlet from the compressor provides a signal to the FADEC to allow it to set the waste gate appropriately.
How many air sources are there to feed the turbocharger system?
4
2 per engine, filtered RAM air or unfiltered warm air from the engine cowlings.
Why does air pass through an inter cooler before entering the engine?
To regulate the temperature
How does the ECU calculate the correct setting of the waste gate?
From a sensor located in the outlet from the compressor.
Where is the fire detection system located on the aircraft?
Located in each engine bay
At what temperature is the unit triggered to deliver a fire warning annunciation?
250degC
How is the system tested before engine start?
The annunciation is tested with the GEAR/FIRE test switch
Is the system a de-ice or anti-ice system?
It is called a de-ice in the book however it operates like an anti-ice.
What are the approved fluids to be used?
AL-5 (DTD 406B) and Aeroshell Compound 07
What is the base compound of the anti-ice fluid?
Glycol-based
What is the maximum tank capacity and useable anti ice fluid?
30Litres useable
How many operating modes are there for the anti-ice system? What at the max operating times?
OFF
NORM max 2.5 hours (5mins per litre)
HIGH max 1hour (2mins per litre)
MAX operates continuously for 2minutes
Where is the anti-ice fluid dispersed from on the aircraft?
Wing leading edges Horizontal stabiliser leading edge Vertical Stabiliser leading edge Propeller Windscreen
Where are the anti-ice main pumps located?
In the nose of the aircraft
When NORM mode on the anti-ice system is selected which pumps run and for how long?
Both pumps are used to provide intermittent fluid flow
30 secs ON 90 secs OFF
When is the DEIC LVL LOW annunciation illuminated?
When 10 litres of anti-ice remains
What is the purpose of the ALTERNATE switch?
Provides power from the RH busbar instead of the normal LH busbar.
In what conditions do we select the anti-ice on?
Below +3 deg C
What voltage is the aircrafts system AC/DC?
28 Volt DC system
How is power generated to the electrical system?
By 2 x 60Amp 28Volt DC engine driven alternators. When the alternators are off, power is provided by a 10amp 24V main battery.
Where are the engine driven alternators located?
One in each engine
Where are the power output lines for the alternators connected to?
Alternators connected to Dedicated L/R main busbars via their respective alternator switches.
What indication do we have to know how much power is being supplied to the electrical system? How is this measured?
Numerous indicators on the MFD displayed in Volts/Amps
