SM Special (final stage revision) Flashcards
Thrust is produced by the…..
force required to accelerate the mass of air through the engine
Gas TURBINES convert kinetic energy into mechanical energy, while combustion chambers…
convert chemical energy into kinetic energy
What is the effect of RAM effect on thrust?
Total recovery as forward speed increases
Is the average cruise EPR independent of TAT?
yes
What are the advantages of the free power turbine?
Lower starting torque, variable prop speed, high torque at low rpm, instant response (compared to turbofan)
What is the purpose of the NTS?
Increases blade angle to stop the propeller driving the engine
What is the purpose of the TSS?
Automatically feathers the propeller in the event of an engine failure
What does the safety coupling do?
Disengages the reduction gear from the engine (it is a backup to the NTS)
What are the advantages of a centrifugal flow compressor?
Simple and cheap
What are the advantages of an axial flow compressor?
Axial thrust, higher compression ratios, better power to weight ratio
What is the purpose of the bleed valve for engine operation?
Increases mass airflow over early compressor stages at low RPM
On startup, what indications will indicate a successful light-up?
Increasing EGT, TOT, or ITT.
During subsonic flow through a duct, what happens to density?
Remains constant
What is the difference in airflow through a duct between sonic and subsonic flow
Everything supersonic is backward, and density changes.
Why is air slowed down in the combustion chamber>
To prevent flameout
In the engine compressor, which blades experience the highest air loads?
Rear compressor
What is the purpose of the Variable Inlet Guide Vanes?
Reduce AoA on the front compressor blades at low RPM
In the combustion chamber, is the hottest temperature at the front or back of the primary zone?
Back
In turbojet aircraft, does range increase or decrease with an increase in altitude?
Increase with an increase in altitude
What is the issue with water in the fuel system? (CIM)
Corrosion, Icing, Microbial growth (C I M)
Compare AVTUR to AVGAS.
Higher SG, lower volatility, higher flashpoint, higher calorific value (by volume).
What is the purpose of a spring loaded relief valve in a fuel system?
Provides fuel supply in the event of a filter blockage
If a FMC detects a difference between the FMC calculated fuel and the fuel gauge indication, what happens?
The pilots are alerted with a fuel quantity error message, and the pilots then have to decide which quantity to use.
What happens to the range of an aircraft at the SG reduces?
Reduces
What is the purpose of baffles in a fuel tank?
Prevent CoG changes
What is the purpose of vents in the fuel tank?
Decreases pressure between the tanks
What is the most common type of high pressure fuel pump?
Swash plate
What is the most common type of fuel boost pump?
Impeller type
Aeration of the fuel lines is prevented by what device?
Boost pumps
For what reasons would an APU shut down? (LOP HET HE DO)
Low oil pressure, high oil temp, high EGT, overspeed, duct overheat (LOP HET HE DO)
What are the errors in the machmeter?
Instrument and position
The start of the transonic speed range is indicated by…
Mcrit
At what speed does shockwave related drag wave problems occur?
Mcdr
At which point is all the airflow supersonic?
Mdet
What happens to the static pressure behind an expansion wave?
Reduces (air accelerates to stay supersonic)
Is there a change in flow direction through a normal shockwae?
No!
What is the general reason as to why sweepback is beneficial for jet aircraft?
Delays onset of compressibility effects (wing flies ‘faster’ before top surface acceleration produces shockwave problems)
What are the advantages of sweepback?
Increases Mcrit (and therefore Mcdr), increases force divergence mach #, improved lateral stability ,less gust sensitive
What are the DISadvantages of sweepback?
Tendency to stall tip first (causes nose pitch up as the CoL moves forward), poor low speed lift, reduced Cl max, duth roll, higher stalling AoA
Does spiral stability (dutch roll) increase or decrease with an increase in altitude?
Increase (strong lateral stability compared to directional stability)
When does spiral divergance occur?
Weak lateral stability, strong directional stability
What effect do spoilers have on lateral control?
Enhance…i.e. help roll
Slats…..while flaps….
slats re-energise the boundary layer while flaps increase the camber
What data does a flap limiter monitor to retract the flaps?
Airspeed
What happens to the power and thrust curve as flaps are deployed?
Move up and left
What do slotted flaps do?
Increase the camber + preserve boundary layer flow
What do fowler flaps do?
Increase camber and chord
An ‘aileron lockout’ messages appears, the pilots will experience…
a degraded roll control at low speed
As altitude, what happens to the aerodynamic dampening?
Reduces due to increased TAS
When does the stick pusher activate?
At the speed BELOW which controlled level flight is not sustainable. Therefore can fly at the stall speed without stick pusher activating
A pilot experiences buffet during a turn at high altitude, is this high or low speed buffet?
Could be either
What is the effect on Va with changes in altitude?
Higher alt = higher Va
How is SAR correctly expressed?
100nm/1000kg
Vimd is the speed for
Min drag = best endurance
1.32 Vimd is the speed for
Best range (best TAS to drag ratio)
Vx occurs at
Vimd
Vy occurs at
1.32 Vimd
How would you achieve maximum range?
Cruise climb + 1.32Vimd + design RPM
Does the AoA for best range change with weight?
No, as weight decreases, the speed decreases
What is the effect of wind on an ETP?
Moves into wind
What effect will a rearward CG have on cruise speed?
Results in higher cruise speed
During OEI ops, where will the balance ball sit if aileron and rudder are used?
half a ball toward the live engine
During OEI ops, where will the balance ball sit if rudder are used?
Centred
During OEI ops, where will the balance ball sit if aileron is used?
Fully displaced toward live engine
In gusty conditions, what is the rule of thumb?
Add half the wind (max 15kts), and half the gust (max 20kts). e.g. 20ktG30, add 10 + 5 = Vref + 15
What are the advantages of AC over DC?
Smaller, low current, lighter
In normal operations, are Bus 1 and Bus 2 connected?
Yes, they act as a single bus
For bus 1 and bus 2 to act as a single bus, how are the engine driven generators + apu connected?
Only one will supply power to bus because they can’t be syncronised
In a series wound generator, as load increases,
voltage increases
In a shunt wound generator, as load increases,
voltage decreases
In a compound generator, as load increases,
voltage is constant
In an AC generator, if the residual voltage is 0, and there is no battery, can it be restarted?
Yes, if it is a PMG
What are the advantages o constant frequency?
Load sharing, paralleling, low current @ high voltage.
If the CSD overheats, will it disconnect itself?
No, must be monitored
If the CSD is disconnected, how is it reconnected
mechanically on the ground
What is the purpose of the bus bar?
Main point receiving electric current from Gen or Batt
What is the purpose of the generator bus switch?
Connects buses together
What is the purpose of a split system breaker (SSB)?
Automatic control and protection by preventing paralleling of systems that can’t be synchronised
What is the normal unit of measurement monitored on the electrical system?
kW, and kVAR is used to monitor health of the voltage regulator
If the aircraft generators are powering the electrical system, can ground power be connected?
No
What does a full wave bridge rectifier do?
Used to DC power for the field excitation of the main generator
What happens when the generator FIELD breaker trips?
Voltage regulator disconnects from the excitation field
What happens when the Generator Control Relay trips?
Associated generator is disconnected from it’s bus
When is the static inverter used?
In the event of a failure of the AC power.
How are batteries charged?
At constant voltage
What are the advantages and disadvantages of NiCad batteries?
Faster recharge, safer. Higher risk of thermal runaway, and ventilation still required.
What are baffles in the hydraulic system for?
Prevent foaming
What is the purpose of the restrictor valve?
Prevents cavitation
What is the purpose of the accumulator?
Provides pressure in an emergency, reduces knocking/hammering, dampens pressure fluctuations
What is the purpose of the pressure relief valve?
Prevents hydraulic seals from blowing out
What is the purpose of the shuttle valve?
Allows alternate system to pressurise the lines
What does a priority valve do?
Automatically shuts off supply to non-essential services
If the aircraft has 2 seperate independent hydraulic systems, how is the power distributed?
some systems are powered by both systems simultaneously
What is the purpose of the rudder ratio changer?
as speed increases, rudder deflection decreases
What is the aerodynamic purpose of an internal flexible seal attached to leading edge of a control surface?
Aerodynamically balances the control by reducing hinge moments
With the all flying tail (different to STAB trim!!), what happens as the pilot moves the control column?
Tailplane moves and the elevator moves in the same direction
At what speed will the stick shaker engage?
1.05Vs to 1.07Vs (different sources say different things)
Regarding the CAM on the nose wheel, what is it’s purpose?
Centre the nosewheel before retraction to fit in the wheel well
What is the purpose of the follow-up linkage?
Puts tiller in neutral position
What is the advantage of the trailing bogie wheel?
Allows softer nose wheel touch down during landing
Where are safety switches located?
On the oleo strut
Where are thermal plugs located?
In the wheels (not the tyres)
What is the purpose of chines?
deflects water and slush
What is the purpose of marstand?
reduce nose wheel shimmy
Can anti-skid be overridden by the pilot?
No
What is the purpose of the modulator valve in the autobrake system?
Provides protection for the hydraulic system against damage from anti-skid
In the event of a bleed air duct leak, what must occur?
It must be isolated and turned off to prevent structural damage
When is bleed air vented overboard?
Low RPM
What items are anti-iced pneumatically vs electrically?
anything to do with the engine or wings is pneumatic, and any probes or propellers are electric.
How are turbo-props ‘de-iced’?
Electrically on a periodic cycle
At what altitude will the cabin altitude horn sound, and what altitude will the oxygen masks deploy?
10,000ft and 14,000ft
What is the purpose of the positive relief valve?
Relieves cabin pressure (limits max pressure differential)
What component of the pressurisation system limits max pressure differential?
Positive relief valve
What is the purpose of the negative relief valve?
allows air into the cabin so that the cabin altitude is equal to or less than a/c altitude.
In an air cycle system, where is the coldest air?
In the expansion turbine
When are the RAM doors in an aircon system fully open?
In unpressurised flight to remove smoke/toxins
What is the purpose of the water separator in the aircon system?
Removes water which condensed in the system during the cooling process before it enters the cabin
When is the cockpit voice recorder active?
1st checklist to 30 min after last checklist
When is the Flight Data Recorder active?
when a/c first moves under own power to complete stop (keeps last 25hrs)
When will the T/O config warning alarm?
Brakes, flaps, slats, spoilers, stab
When will the LDG config warning alarm?
In the air with LG not down and
- <800ft RADALT thrust set to idle
- Flaps selected with gear up
What are the 5 modes of the GPWS?
- excessive descent rate (sink rate, whoop whoop pull up)
- Excessive terrain closure rate (terrain, whoop whoop pull up)
- Altidue loss after T/O (don’t sink)
- Unsafe terrain clearance with flap not in LDG config (too low flap, too low terrain)
- Below glide slop (glide slop, GLIDE SLOPE) (loudness depends of degree of fuckup)
Why would you inhibit RAs on the TCAS?
During OEI (aircraft may not be able to meet climb performance), or formation flight
What is the range of the TCAS system?
45nm, with 30 a/c displayed at once
When will proximate traffic become a TA?
Within 40 seconds to closest point of closure
When will TA become a RA?
Within 25 seconds to closest point of closure
What is a autopilot hardover?
Uncommanded full servomotor deflection
What systems are there to protect from autopilot hardover?
rate dampeners and torque limiters
What is the purpose of the FMS?
Achieves either best economy (0) or fastest trip (999)
What are outer loop inputs?
Air data (such as altitude/HDG/IAS)
What does THR HLD mode entail?
Auto-throttle is de-energised, pilots can move thrust levers
Land 3 and Land 2 indicate
Fail Operational and Fail passive systems
What thrust settings are used in FLCH mode?
Max power in climb, idle for descent
When does FLARE mode arm and engage?
Arms at 1500ft RA and engages at 45ft
When is FLT idle deactivated?
Remains on until 5 seconds after touchdown or reverse thrust activated
If a derated TO is conducted and there is an engine failure, does the crew need to increase thrust?
No, the set thrust will be sufficient to maintain obstacle clearance
Can VS and VNAV modes be selected together?
No
SPD=FD vertical mode
SPD=FD vertical mode
Flight Director bars are controlled by the
Flight Director Computer
When is the autoland integrity test conducted?
At 1500ft
Model Following is not an example of autopilot protection
Model Following is not an example of autopilot protection
TAT compensates for
Adiabatic compression
The bank angle selector in AUTO mode will use what AoB?
15° at high TAS, 25° at low TAS
Is MAP mode orientated track up or HDG up?
HDG up
What is the purpose of the range acquisition arc?
Displays computed ToC position based on REAL conditions
is HDG on MAP mode true or magnetic?
Determined by pilot selection or latitude (extreme latitudes are in True.
What will the EFIS screen display in the event of a failed SG?
Blank screen
What pilot action is required in the event of a SG failure?
Manually select different symbol generator source
Below 1000ft RADALT, what colour is the DH?
Magenta
At 50ft above the DH, what happens to the DH on the ADI?
Changes from Magenta to amber, and aural chime alerts
passing DH, what happens to the RA scale colour?
Changes from white to amber.
What happens to the DH and RA on the EADI when a negative DH is selected?
DH is blank, RA remains the same.
Plan mode is always referenced…
True North UP
In plan mode, is the TRK line in magnetic or true?
Magnetic (even though orientation is True north up). The true north up is the bottom half of the screen.
What modes is the WX radar visible?
Map, expanded ILS and VOr
What are the range and height requirements for proximate and other traffic?
proximate <1200ft <6nm, other >1200ft >6nm
When will the TCAS be inhibited?
GPWS, stall warning, windshear warning
FMC needs valid data from…
at least 1 IRS
What speed is bugged on the speed tape during takeoff?
V2
What is an example of a conditional waypoint?
Altitude
What systems are part of the Standby Navigation System?
CDU and IRS
What happens if the Captain’s side FMC fails?
FO side FMC must be selected to provided map display on captain’s EHSI. Both pilots must use the same range.
What pages of the CDU can conditional waypoints be entered?
Arrivals and Departures page
LNAV will follow a great circle between two points
LNAV will follow a great circle between two points
How will the aircraft enter a hold in LNAV mode?
Based on actual track.
If the aircraft passes the final waypoint entered in the FMC in LNAV mode, what will it do?
Maintain current HDG
What is the minimum requirement for RNAV operation?
1 FMC + 1 CDU with radio updating
With the airspeed window on the AFDS panel blanked, the command airspeed bug is being controlled by the….
FMC
Pressing cancel on the EICAS control panel will…..
select the next page
In a 2 compass system, if the Captain’s HSI displays a HDG flag, what will be indicated?
A HDG flag on the FO’s RMI
Can the SNS provide LNAv or VNAV guidance?
No, only HDG SEL is available
Where does the SNS get it’s computing capability?
Has it’s own permanent computing capability (contained in the CDU)
During SNS operations, do the radios have to be tuned manually?
Yes
What is earth rate compensation?
Accelerometer platform forced to tilt in proportion to the earth’s turning rate
Where is compensation in a gyrocompassing system sent?
to the x gyro
How is north alignment maintained in an azimuth wandering system?
Azimuth gyro uses earth rate + transport rate
What is the main difference in a wander azimuth system?
Some earth rate compensation is sent to the Y gyro
What is the maximum radial error rate of an INS/IRS?
3 + 3t (t=no. of hours in nav mode)
What is the difference between the IRS and INS?
IRS = ring laser gyros, INS = normal gyros
What are the advantages of an IRS over the INS?
No moving parts, higher mean time between failure, require less power, digital output
What inputs are required to the IRS to derive current true heading?
Nothing, the IRS can derive current true heading independent of other inputs
What factors increase Vmca?
Rear CoG, gear down, AoB >10°, windmilling prop, increased thrust
What condition usually leads to a tailstrike?
Rotating too early or rapidly
As an aircraft accelerates from subsonic to supersonic, what happens to Cd?
Increases then decreases
As an aircraft accelerates from subsonic to supersonic, what happens to Cl?
Increases then decreases
What is the effect of weight on Vmca?
No effect (it is the distribution of weight that has an effect)
What AP modes (for A/T and pitch) would you expect during a climb during a STAR?
N1/VNAV SPD. N1 indicates max climb thrust, VNAV SPD indicates speed maintained with pitch.
Upon level off, what AP modes (for A/T and pitch) would you expect during a level off?
SPD and VNAV PTH
What will the AP mode indication be during a go-around?
N1/VNA SPD/LNAV
If the ‘fuel disagree’ message appears, will the system accept the data input from the pilot or calculated by the FMC?
Pilot
At 80kts during the TO, the A/T mode changes to THR HOLD, what does this indicate?
The n1 thrust will be held.
What is bootstrapping?
If power is lost then reference will not be lost. E.g. the left IRS is connected to Capt standby RMI and right IRS to FO standby RMI, if the Captain’s EHSI screen (supplied by the LEFT IRS) fails, she will still have the standby RMI.
What does N1 on the A/T indicate?
Max thrust set (predetermined value), and speed will be controlled with Pitch. This is why the associated VNAV mode will be VNAV SPD, because spd is being controlled by pitch.
What does SPD on the A/T indicate?
The thrust levers are used to control speed (and the VNAV profile will be VNAV PTH I think…)
