Aviation Flashcards
What produces the maximum glide range?
Best lift drag ratio, flying at minimum drag speed VIMD (page 2)
What is the effect of weight on the glide range?
Weight doesn’t effect glide range. A light and a heavy plane would fly the same gliding range but the heavier will do so at higher speed or to reach the same point it would have to start the descent earlier (page 2)
What is rate of climb/descent?
Is the height achieved compared to the distance travelled over the ground (page 2)
What is the effect of weight on rate of descent?
If weight increases rate of descent increases (page 2)
What is an airfoil?
A body that produces lift when into an airflow like wings, rudder, tail plane, propeller (page 2)
What is an airfoil chord line?
Straight line from leading edge to trailing edge (page 2)
What is the mean chord line?
Wing area divided by wing span
What is the mean chamber line?
Is the line that cuts the wing in half (page 3)
What is the angle of incidence ?
Is the angle between the aerofoil’s chordline and the aircraft’s longitudinal datum (which is fix for a wing) (page 3)
What is angle of attack?
The angle between the chord line and the airflow (page 3)
What is washout on a wing ?
A decrease of angle of incidence from the root to the tip to fight against early wing tip stall (page 3)
What is dihedral ?
Is the upward inclination of the wing to improve lateral stability ex.PA28 (page 3)
What is anhedral ?
Is the downward inclination of the wings to decrease lateral stability ex.antonov Russian plane (page 3)
What is lift?
Lift is the force caused by the movement of an aerofoil into a airflow (page 3)
What is the lift formula?
L= 1/2rho v2 S CL
What is CL?
Is made of angle of attack and chamber (page 4)
Describe CoP?
The CoP is the point where Lift force acts (page 4)
Describe the L/W pitching moment ?
If the forces of L and W are not acting to the same point there will be either a nose down or nose up pitching moment depending whether the CoG is acting in front or behind the CoP (page 5)
Describe aspect ratio
Ratio of wing span and geometric chord
High aspect ratio = high lift
Low aspect ration = low lift
During what phases of flight is lift the greatest?
During take off (page 5)
What are the forces acting on an aircraft in flight?
Lift Weight Thrust Drag (page 1)
What is the direct lift control ?
Elevator / stabilizer (page 6)
What are high lift devices ?
Slats ( leading edge flaps - Kruger Flaps),
Trailing edge flaps ( fowler flaps)
Slots (boundary layer control)
(Page 6)
What is Drag ?
Drag is the resistance of motion of an object (page 6)
Define the two major type of drag?
Induced drag: as speed increases induce drag decreases As speed decreases induce drag increases Parasite drag -form drag -interference drag -skin friction Page 6
Describe the drag curve of a piston propeller aircraft?
Page 7
Describe the drag curve of a jet aircraft?
-flatter drag curve
-not noticeable change of flying qualities other than a light lack of speed stability
-VIMD is higher because swept wing is more efficient against profile drag
Page 8
Describe the pitching moment associated with the T/D couple?
With jet plains with engines under the wing the increase and decrease in thrust causes the plane to pitch up or down
Page 9
What are high drag devices?
- trailing edge flaps
- spoilers
- landing gear
Page 9
What causes/are wing tip vortices?
Are caused by the high pressure under the wing trying to reach the low pressure over the wing, the two pressure mix at the trailing edge and wing tip and cause vortices
Page 10
What are the effect of span wise airflow over the wing?
Normal wing airflow
- create wing tip vortices
- reduce aileron efficiency
- the flow that tries to reach low pressure from bottom creates extra disturbance on wing tip causing wing tip stall
Page 10
What are the effect of wing tip vortices?
- create induce drag
- create turbulence
- down wash affects the direction of the relative airflow over the tailplane which affects longitudinal stability
Page 11
How do you prevent span wise flow?
Fences and vortex generators which direct the airflow perpendicular to the upper wing leading edge
Page 11
What is the purpose of vortex generator / fences?
Vortex generators disturb the airflow improving ailerons effectiveness because disturbed airflow sticks to the wing longer
Fences they impose in front of the airflow that tries to reach the wing tip when the root has stalled, keeping the airflow over the wing tip un-stalled
Page 11
What are winglets and how do they work?
Are little fences on the wing tip that help reduce drag and increase fuel consumption by preventing the mixing of the bottom and upper wing airflow
Page 11
What limits an aircraft structural weight ?
The lift capability of the aircraft therefore the wings
Page 12
What are the effects of excessive aircraft weight?
Take off and landing distance is increased Rate of climb of climb is reduced Range and endurance is reduced Max speed is reduce Stall speed is increased Manoeuvrability is reduce
Page 12
Describe CoG.
Is the point where weight acts
Page 12
Describe (component) arm?
Is the distance between the datum and where the weight component of something acts
Page 12
Describe CoG moment?
Moment = arm x weight
Page 13
What is the pitching moment of the L/W coupled balanced?
The tailplane
Page 13
Describe the CoG range ?
Is the furthest toward and aft position where the CoG acts and where the tailplane can help the aircraft to be longitudinally stable
Page 13
What are the reason/effects of keeping the CoG inside its limits ?
Ensure
- Not too nose or tail heavy
- aircraft pitch control is not compromise
- minimum horizontal tailplane deflection
What are the effects of CoG outside limit range ?
Forward CoG
- nose heavy
- stable
- stall speed increases
- fuel flow increase
- range decreases
Aft CoG
- tail heavy
- unstable
- stall speed decrease
- fuel flow decreases
- range increases
Page 15
If you were loading and aircraft for max range, aft of forward CoG?
Aft
Page 16
How does a forward CoG increase stall speed and why.
Weight is a factor affecting stall speed, if weight increases stall speed increases
Page 16
Why does a jet aircraft have (need) a large CoG range ?
Because it’s CoG can change with the change in weight during the flight
Page 17
How does an weight affects an aircraft flight profile point.
The heavier the plane the soon it would need to start its descent
Page 18
What is positive G force?
1 g
Page 18
What is negative g force ?
Above 1 g
Describe how you would design a high speed aircraft wing?
Thin, minimal chamber, swept wings
Page 19
How does a swept wing aid the increase in its critical Mach number?
The airflow going over the swept wing “sees” a already thin wing even thinner due to the oblique backward shape.
A thin wing equals small chamber therefore slow acceleration.
Swept wing = slower air velocity = higher Mcrit = later shockwaves onset = later drag onset
Page 19
Describe how you would optimise the lift design of a swept wing?
Add lift devices
Page 20
What advantages does a jet aircraft gain from a swept wing?
- High Mach cruise speed
- stability in turbulence
Page 20
What disadvantages does a jet aircraft suffer from a swept wing ?
- poor lift
- stall speed increased
- unstable at low speed
- wing tip stalling tendency (due to greater angle of incidence)
Page 21
Where does a swept wing stall first, and what effects does this have on an aircraft’s attitude ?
At Wing Tip
After the wing tip has stalled the CoP will move inward and forward towards the leading edge, this will cause the nose to rise and the plane to stall.
Solutions:
- increase wing tip chamber
- wash out or twist on wing tip
Page 21
Explain speed stability.
A speed is said to be stable when after being disturbed from its trimmed state it returns back to its original speed.
Unstable is when the speed keeps changing after a disturbance
Page 22
What’s is Mach number?
Mn = TAS/LSS
LSS = 38.94 sq root of T
T in Kelvin = 273 + Celcius degrees
Page 23
What is the critical Mach number ?
Is the number at which airflow becomes sonic
0.72 is a typical Mach number where airflow becomes sonic Mach 1 over the upper surface of the wing
Page 23
Describe the characteristics of critical Mach number ?
what happens when Mcrit is reached ?
- Initial Mach buffet due to shock wave
- Increase in drag
- Mach Tuck
- Possible loss of control
Page 23
Describe the change in the centre of pressure as an aircraft speed increases past the critical Mach number ?
As speed increases above Mach critical number the shockwave created will get bigger and move backwards and backward. The highest lift is in front of the shock wave so the CoP will move with it. As the CoP moves rearward it will lift the tail and pitch the nose down causing Mach Tuck
Page 23
What is Mach Tuck?
As speed increases above Mach critical number the shockwave created will get bigger and move backwards and backward. The highest lift is in front of the shock wave so the CoP will move with it. As the CoP moves rearward it will lift the tail and pitch the nose down causing Mach Tuck
Page 24
What is the purpose of a Mach Trimmer?
To compensate for Mach Tuck
Page 24
What is Mach Trimmer and what is used for?
Is a system that with a proportional upwards movement of the elevator or variable incidence stabiliser maintains the aircraft’s pitch attitude above its Mcrit
Page 24
What are the effects of compressibility?
- airspeed indicator shows and over-read error
- shock wave / drag
Page 25
Explain speed margins
A speed margin is the difference between the aircraft’s normal maximum operating speed and its higher certified testing speed
Page 25
What is coffin corner?
Coffin corner is reached when the aircraft reaches its absolute ceiling where stall speed and Mach critical number are the same.
Stall speed is the lowest speed to fly at before reaching stall
Mcrit is the maximum speed to fly at before reaching stall
Page 27
Explain why an aircraft stalls
When a wing is not able to produce lift anymore
Page 27
What properties affect an aircraft’s stall speed ?
- weight
- altitude
- wing design
- configuration
- prop speed
Page 27
How does the stall speed varies with weight ?
If weight increases stall speed increases
As weight increases we can either increase wing size to produce more lift or increase speed always to produce more lift
Page 27
What wing design the delay the break up of airflow (stall)?
- wing slots
- lower angle of incidence
- greater Chamber for a particular wing section (wing tip)
Page 28
What changes the aircraft angle of attack at the stall ?
The movement of the CoP
Page 28
What happens to the stall speed at very high altitudes and why ?
The stall speed increases
Because of:
- Mach number compressibility effect over the wing
- compressibility error on the IAS
Page 28
What is a super stall ?
Also known as Deep Stall is mainly associated with rear engine, high T-tail swept wing aircraft.
As the plane is reaching the stall the turbulent airflow created by the wings flying at low speed is hitting the T-tail causing it to be ineffective cause it would need a clean airflow. As the nose pitches up the elevators are not working therefore the nose will keep rising no stop.
Page 29
What systems protect against a stall?
Stall warning and stick pusher
A stick shaker is activated at or just before the onset of pre stall buffet
Page 30
What is Dutch Roll ?
It’s yaw and roll together. It’s a oscillatory instability associated with swept wings.
Page 30
What causes Dutch Roll?
Swept wings
When a yaw is induced the adverse action is for the aircraft to roll. As the aircraft rolls the outside wing is producing more speed and therefore more lift to a point where it stalls. This cause a wing drop and an adverse yaw towards the dropped wing at this stage the new outer wing is producing more speed and more lift to a point where now it stalls and the aircraft will yaw towards it. This can continue endlessly.
Page 30
What is the recovery technique from Dutch roll?
Use of opposite ailerons (2-3 times)
Rudder will not be effective as the pilot is not quick enough to counteract the yaw.
Yaw damper
Page 30
What prevents Dutch Roll?
Yaw Damper which improves the effectiveness of the fin
Page 31
What is spiral stability and instability ?
Spiral stability is the tendency of an aircraft to return into level flight on its on from a turn on release of ailerons.
Spiral instability is the opposite usually found with planes with large fin where the fin will jump into action creating a side slip which will steep the turn until the point of spiral dive.
Page 32
What is lateral stability ?
Is the tendency of a aircraft to return to a laterally lever position around he longitudinal axis on release of the ailerons into a side slip.
Two main features:
- wing dihedral
- side loads produced on the keel surface (fin)
Page 32
What is Longitudinal stability ?
Is the aircraft’s natural ability to return to a stable pitch position around the lateral axis after a disturbance
Page 32
Describe stability at high altitudes?
Stability is reduced at high altitudes in term of dynamic stability mainly because aerodynamic damping(restoring moment) decreases with altitude
Page 34
Whenever in-flight maneuvers result in rotation of an aircraft about or near its center of gravity, a restoring moment is created by the changed relative airflow. This restoring moment opposes the control demands, and it arrests maneuvers as and when the control demands cease. The effectiveness of the restoring moment (known as aerodynamic damping) is dependent on the dynamic pressure (i.e., indicated air speed). As altitude increases, true air speed increases for the given equivalent air speed, resulting in decreased aerodynamic forces. Thus, at higher altitudes the pilot must apply greater opposite control movements to arrest rotation.
What are the 4 flying qualities penalties experienced at very high altitude?
- Restricted operating speed range
- Reduced manoeuvrability
- Reduce aerodynamic damping
- Reduced stability
Page 34
What are the primary control surface?
Ailerons, elevators, rudder
Page 35
What is the elevator and how does it work?
Page 35
What is the aileron and how does it work?
Page 35
What is the rudder and how does it work?
Page 35
How does the effectiveness of the control surfaces vary with speed?
As speed increases they become more effective
Page 36
What is elevator reversal?
At high speed the air loads over the elevator can be so strong to cause a twisting moment that can push the elevator back to neutral or opposite position cause a reverse of aircraft’s pitch attitude
Page 36
What is adverse yaw?
As the aircraft rolls to the right the nose yaw to the left, caused by the downgoing aileron on the left wing.
Features:
- frise ailerons
- differential ailerons
Page 36
What is aileron reversal?
At high speed the air loads can produce a twisting moment and cause the downgoing aileron to reverse upwards and cause an adverse roll (a roll in the opposite direction)
Page 36
What is a yaw induced adverse rolling motion, and when is it likely to occur?
Yaw left roll right and vice versa.
It happens at high speeds
Page 37
What are spoilers and how do they work?
Spoilers consist of opening panels over the wing. They can work as spoiler, differential, to spoil the airflow, create more drag to help in a turn.
They can work as speed breaks, working in parallel to increase drag and dump lift on landing and to slow the plane down
Page 37
What are the 3 purposes of spoilers?
- roll control
- speed brakes
- ground lift dumpers
Page 38
Give six reasons for spoilers?
- ailerons are limited in size therefore effectiveness
- on this swept wing ailerons are too large and can experience air loads twisting moment
- ailerons lose effectiveness at high speeds
- to fight adverse rolling moment with yaw
- due to lag in engine response to slow down
- dump lift off during rejected take off or landing
Page 38
What limits the use of spoilers and why they blow back?
Very high speeds which cause them to blow back
Page 39
How is spoilers blow back prevented ?
Follow speed limits
Page 39
How do you correct spoilers blow back ?
Reduce speed
Page 39
What do leading edge slats do?
Increase wing chamber, increase lift, decrease stall speed
Page 39
What are Kruger flaps?
They are leading edge flaps that increase chamber therefore increase lift
Page 39
What are Fowler flaps?
They are three slotted trailing edge flaps
Page 40
What is the primary use of flaps on jet aircraft ?
To increase lift by increasing wing area
Page 40
What are the effects of extending flaps in flight?
Mainly increase lift and create a nose up pitching pitching moment
Page 40
What are the effects of raising flaps in flight?
Lift loss
Page 40
How do flaps affect take off ground run?
The right a degree of flaps will improve lift and reduce the take off run
Page 41
What are the proposes of roll and yaw dumpers and how do they work?
A Yaw Damper is a gyro system that applies opposite rudder, especially used again Dutch Roll.
A Roll Damper applies opposite roll in turbulence controlling lateral stability
Page 42
Describe parallel Yaw Dampers?
They works in parallel with the pilot’s pedals. Their activity is reflected in the rudder bar activity because they move the pedals
Page 42
Describe series yaw dampers?
It operates on the rudder but the system doesn’t actually move the rudder pedals
Page 42
What is a stabiliser / variable incidence tail plane ?
It’s an all moving tail plane
What is the purpose of a stabiliser ?
The purpose of the horizontal stabiliser is to provide s longitudinal balance force to the aircraft. The stabiliser covers large and small pitching moments
Page 43
For are the 4 reasons for a variable incidence tailplane stabiliser especially on jet aircrafts ?
- provide balance force for large centre of gravity range
- provide a balancing force for a large speed range
- to cope with large speed changes
- to reduce elevator trim drag to a minimum
Page 43
Describe the effects of a stuck stabiliser.
Is degraded longitudinal balancing ability which is due to the employment of the less powerful elevator in providing this longitudinal balancing force
Page 43
What is the best CoG position with a stuck stabiliser and why ?
is the AFT position.
Because it need to be tail heavy to improve elevator movements
page 43
What is the required action with a stuck stabiliser ?
- divert to nearby airfiled
- move the CoG aft
- reduce speed as late as possible
- plane a long final approach
- use a reduce flap settings
page 44
describe a runaway stabiliser condition and required action ?
it's when the brakes te hold the stabiliser into a certain position don't work anymore. required action: - hold control column firmly - disengage the autopilot - cut stab trim out - hold trim wheel
page 45
describe the effects of a jammed/degraded elevator ?
will result in a less effective elevator manouvrability
what is the best CoG position with a jammed/degraded elevator?
AFT, to lessen the need for large pitch control demand
what is the required action for a jammed/degraded elevator ?
if the elevator is jammed than it’s unusable.
if the elevator control is degraded that it could be assessed if can still be safely used.
actions:
- move CoG aft
- plane a long final
- use low flap settings
page 45
describe the effects of a failure/reduction in elevator feels ?
whenever the feel is reduced great care must be exercised in its use. slow and smooth movements
page 46
what it the best CoG position with a reduced or failed elevator feel system?
forward, to reduce the weight over the elevator feel system, since it need gentle movements, the lighter the better
page 46
describe the effects of the air loads on a control surface and how this effects are managed ?
hinge moment of air load force = lift force(air load) x arm
lift force experienced depends on
- airspeed
- angle of deflection
page 46
what is a tab surface and what can it be used for ?
is a small hinged surface found on a primary flight control, it can be used for:
- trimming
- control balance
- servo operation
page 46
what is a balanced tab?
reduces the overall hinge moment like a trim tab
what is a hinge/horn balance ?
hinge balance sets the hinge line back into the control surface thus reducing the center of pressure to hinge line harm.
horn balance is a protruding control surface that produces a balancing force in the opposite direction of the main lift reducing hinge moment.
page 47
what is a mass balance?
it’s a mass weight that keeps the control surface into position and fights against the twisting moment caused by air loads.
page 48
why are control surfaces hydraulically operated on large aircraft ?
it is simply beyond the strength of a pilot
page 48
why does a powered control surface needs a artificial feel system ?
cause they do not feed back to the pilot any sensory information
page 48
how does an artificial feel work ?
the simplest form is a Spring Box or otherwise a Q Feel which is a sophisticated computer based artificial feel
page 48
what is Q Feel and where it is used ?
Q Feel which is a sophisticated computer based artificial feel used on aircraft with powered flight controls
page 49
what are the inputs to Q Feel ?
- static and dynamic pressure
- control surface angle of deflection
page 49
what are active(automatic) controls?
an active control is a control surface that moves automatically
page 49
what is thermodynamics ?
is the study of the behaviour of gases under variation of temperature and pressure
page 51
explain Bernoulli’s theorem
if the kinetic energy is increased the pressure/temperature energy drops proportionally and vice versa so as to keep the total energy constant
page 51
explain a Venturi
a venturi is a convergent/divergent tube convergent: - velocity increase, - static pressure decreases, - temperature decreases
divergent:
- velocity decrease
- static pressure increases
- temperature increases
page 52
what is the combustion cycle of an piston engine ?
- induction
- compression
- combustion
- exhaustion
page 52
what is compression ration in a piston engine ?
total volume / clearance volume
page 52
what produces the ignition on a piston engine ?
spark plugs connected to magnetos
page 53
what does blue, black, white smoke indicate ?
blue: oil burn (oil leak in cylinder)
black: fuel bun (mixture is too rich)
white: water (high water content into combustion chamber)
page 53
what is engine toque ?
is a force causing rotation, like the twisting moment caused by the spinning propeller onto the engine
page 53
what is a normally aspired pistone engine ?
an engine where its power output is restricted by the cylinder capacity without the help of super/turbo charge
page 53
what is a supercharged piston engine ?
supercharger compresses the air for a greater engine power output.
it is engine driven connected by a belt
page 53
how is the piston engine power output increased to compensate for low atmospheric pressure ?
by the use of superchargers or turbocharges
page 54
what regulates the supercharger to deliver a constant boost manifold pressure ?
the Auto Boost Control
page 54
how is engine power monitored ?
MAP and boost pressure gauge
page 54
what advantages does an aircraft gain from a propeller ?
- creates a high energy slipstream
- has a quick response to throttle input
page 54
what produces thrust in propeller driven aircraft ?
the movement of the propeller through the air
page 55
what restriction does the propeller design have ?
blade length due to:
- ground and fuselage clearance
- blade tip speed
blade chord size due to:
- increase in chord size will reduce aspect ration
- increase in chord size will increase twisting moment
page 56
how does the propeller converts energy horse power to produce thrust ?
thrust = air mass x velocity
page 56
why is the propeller blade twisted ?
to maintain a constant AoA
page 56
how do you define propeller efficiency ?
propeller efficiency = prop thrust / engine bhp
page 56
what are the disadvantages of a fixed pitch propeller ?
that it only produces its maximum efficiency at one predetermine engine RPM, altitude and airspeed.
page 56
what is a variable pitch propeller and why is it used ?
it’s a propeller that can change the blade AoA use to its optimum settings in order to maintain propeller efficiency and aircraft thrust over a wide range of aircraft speed
page 57
what controls the propeller blade angle/ speed ?
the governor (CSU)
page 57
why is a turbo prop aircraft better suited for short regional operations ?
- has a better short field capability
- doesn’t need to fly as high for SFC
- smaller pax capacity for short route
page 58
is there a critical engine in a propeller aircraft ?
Yes, left, if the props both spin clockwise,
No if they spin anticlockwise
page 58
why is the left engine the critical engine on a multi engine propeller aircraft ?
due to:
- slipstream effect
- asymmetric blade effect
page 59
how does a crosswind effect the critical engine ?
we prefer a crosswind to come from the side of the critical engine or failed engine to help restore the force on the fuselage and fight against the yaw moment caused by the failed engine
page 60
what is a wind-milling propeller ?
when the propeller is spinning due to the aircraft speed and not due to the engine power.
as the propeller is not getting propelled by the engine is not causing lift. The airflow that hits the outside of the propeller created a force on the outside AoA (negative AoA) causing the prop to spin.
page 60
can you obtain ground reverse/braking thrust from propellers ?
Yes
ex. Cessna Caravan
page 61
what is propeller feather and why is it used ?
is the 90º pitch(usually a bit less) of the propeller set in that way to reduce drag in case of engine failure
page 61
how do propeller aircraft generate noise ?
from the sheer effect of propeller spinning through the air
page 61
how is propeller noise controlled or reduced ?
- increase blades number
- reduce take off power
page 61
what is the theory of jet/gas turbine engine ?
Newton’s Third Law : Thrust = air mass x velocity
Frank Whittle : when you let air out of a balloon, a reaction propeller the balloon in the opposite direction
page 61
what is specific fuel consumption ?
fuel flow / engine thrust
the ratio of how much fuel you burn compared to engine thrust
page 62
what is the combustion cycle of a jet/gas turbine engine ?
- induction
- compression
- combustion
- expansion
- exhaustion
page 62
why was the jet/gas turbine engine invented ?
- to achieve higher altitudes
- to achieve higher speeds
- to create a simpler more reliable engine
page 62
describe how a jet/gas turbine engine works ?
- induction
- compression
- combustion
- expansion
- exhaustion
page 63
what is a fuel injected system and what are its advantages and disadvantages ?
advantages:
- free of icing problem in the venturi
- more uniform delivery
- improved fuel-air ratio
- fewer maintenance problem
- instant response
- increased engine efficiency
disadvantages:
- subjected to fuel vaporisation (fuel line close to engine)
- difficult to start when already hot
- more susceptible to contamination (fine fuel lines)
- the fuel return line goes only to one tank causing unbalance
page 64
describe maximum take off thrust and its limitation ?
is the max thrust to be selected at take off for not more then 5 min to don’t cause damage to the engine
page 65
describe maximum continues thrust ?
the maximum permissible engine thrust for continuous use
page 65
what is the compression ratio of a gas turbine engine ?
is the difference between the Inlet and Outlet part of either a:
- individual compressor stage, or
- the complete compression section of the engine
page 65
what is the principal of the bypass engine ?
move of the thrust (acceleration of air) is caused by airflow getting duct around the engine core
page 65
what is bypass ratio?
is the difference from the air ducted around the core and the air flowing into the core.
page 66
describe the fan engine and it’s advantages ?
85% of airflow is ducted, the other 15% goes into the engine core. After passing through the front Fan, the air goes into Low Pressure Compressor(N1), where air pressure and temperature start to rise. After it goes into the High Pressure Compressor(N2) where 70% of pressure and temperature rise is experienced. Then it goes through the Diffuser that slows the airflow down to be properly ignited in the Combustion Chamber. The airflow then goes through the High Pressure Turbine that extracts energy to spin the High Pressure Compressor via a connecting rod (spool). Then it goes into the Low Pressure Turbine that extracts energy to spin the Low Pressure Compressor and the Fan
(spool). In the exhaust phase the ducted air and the core air mix. The ducted air causes 80% of thrust the core air 20%.
Advantages:
- smaller engine size
- better propulsive efficiency
- better specific fuel consumption
- reduce engine noise
- contaminations are discharged via the bypass duct
page 67
what are the advantages of a wide-chord fan engine ?
the wider the fan chord, the higher is the balde tip speed, the greater is the generated airflow speed, and the greater is the discharged air pressure, resulting in an increased engine thrust
page 67
describe the triple spool turbo an engine.
it works like a twin spool with the difference that it also has as an intermediate pressure compressor.
Low Pressure Compressor (N1)
Intermediate Pressure Compressor (N2)
High Pressure Compressor (N3)
advantages:
- the compressors have their own connecting shafts
- higher engine thrust
- easier to start
- easier to built and maintain
page 68
why is a fan engine flat rated ?
to give the widest possible range of operation keeping within its define structural limits
page 69
when and where is the jet/gas turbine engine (bypass) at it’s most efficient and why ?
at high as possible and at high rpm speeds
page 69
why does a jet aircraft climb as high as possible ?
because that is where they operate the best .
high rpm speed due to low air density
- minimum cruise airframe drag
- best engine SFC
page 70
what advantages does a jet engine aircraft gain from flying at a high altitude ?
- best SFC although will need to be flown at the maximum endurance speed
- higher TAS for constant IAS
page 71
explain the jet/gas turbine engine’s thrust to thrust lever position ?
at low rpm speed an inch movement of the thrust lever could produce only 600lb of thrust but at hight rpm this could produce 6000lb
page 72
what are the main engine instruments ?
primary: - EPR - N1 gauge - EGT then - N2 gauge - Fuel Flow
secondary:
- oil e temp
- engine vibration meter
page 73
what is EPR ?
is the primary engine thrust instrument
jet engine:
fan outlet pressure to compressor inlet pressure
turbo prop:
max compressor cycle to compressor inlet ambient temperature
page 73
what it the EGT and why is this an important engine parameter ?
exhaust gas temperature tells us the temperature the turbine is experiencing.
the only real threat to engine life is excessive turbine temperature.
page 74
describe an engine wet start, its causes, indications and actions ?
it is a failure to start after the fuel has been delivered to the engine.
indication is:
- EGT does not rise
action:
- close the fuel
- motor the engine
page 74
describe an engine hung start, its causes, indications and actions ?
it happens when the engine ignites but it doesn’t reach its self sustaining rpms due to the insufficient airflow to supply the combustion.
causes:
- low air density (high elevation, hot condition)
- inefficient compression
- low starter rpms
indications:
- EGT above normal
- engine rpms below normal
actions:
- close fuel lever
- motor the engine
to have a successful start in hot and high conditions you need supply more air not more fuel
page 74
describe an engine hot start and its causes, indications, and actions ?
it starts as a normal start but then the EGT rises above max limits
causes:
- overfueling
- air intake/exhaust blocked
- tailwind causing compressor to run backward
- seized engine
actions:
- close fuel lever
- motor the engine
page 75
what is a variable/reduce thrust take off ?
it’s a take off with reduce take off thrust
page 75
can a maximum take off weight aircraft use a reduce take off thrust ?
yes, but needs a longer runway
page 77
why do you use reduced derated take off thrust in a jet aircraft ?
- engine life
- to reduce noise
page 77
why is the risk per flight decreased with a reduces thrust take off ?
- full reverse thrust has more effective quicker
- if engine failure continued take off we can increase thrust
page 77
what are the limitations of a variable/reduce thrust (flex) take off ?
the limitations are all those situations where max power is needed
page 77
what happens to engine pressure ratio on take off roll?
the initial decreasing is caused by:
- engine lag to throttle input
- P7 (exhaust) is lower than P2 (inlet) because before the flow into the engine gets steady, at the initial stage, P2 will always read more than P7
page 78
why does EPR need to be set by 40 to 80 kts on take off ?
to ensure V1 and Vr are achieved by the take off run required rotate point
page 79
what is an engine windmill start, and when is it used ?
a start without the aid of the starter because the compressor are being turned by a natural airflow when airborne.
page 79
what is the purpose of engine relight boundaries ?
is to ensure the correct proportion of air is delivered to the engine combustion chamber
approved relight envelope against height
page 79
what causes a jet/gas turbine upset, and how do you correct it ?
disturbed and turbulent airflow will cause the engine to be upset and stall.
indications:
- TGT rises
- engine vibration
- RPM fluctuations
page 80
what is a jet engine surge, causes and indications ?
a surge is the reversal of airflow through an engine, where the high pressure air the combustion chamber is expelled forward, instead of back, through the compressor with a loud bang and the resulting loss of engine thrust.
causes:
- compressor stage stall
- excessive fuel flow
indications:
- total loss of thrust
- TGT rise
actions:
- close the throttle slowly
- adjust aircraft attitude
- reopen the throttle slowly
page 81
why are bleed valves fitted to turbine engine ?
- to provide bleed air to auxiliary system air conditioning engine cooling accessories colloing engine e wingtip anti icing system
- to regulate the correct airflow pressure between different engine sections
page 81
why gas turbine engine have auto igniters ?
they work by sensing a particular value of incidence of the aircraft and ignite to make sure the engine doesn’t stall in case of turbulent airflow
page 81
what is FADEC ?
full authority digital engine control
page 81
what fuels are used commonly for jet aircraft ?
Jet A1 and Jet A
difference is A1 freezes at - 50ºC, A at - 40ºC
page 82
how to jet gas turbine engine generate noise ?
jet’s faster displaced air moves into the slow ambient air
page 82
how is jet gas turbine engine noise controlled reduces ?
- bypass engine
- flex thrust
- maximum rate of climb of take off
page 82
is there a critical engine on a jet gas turbine aircraft ?
No but there are crosswind considerations to be made
page 82
describe a typical aircraft fire detection and protection system ?
- overheat and fire detection loop
- fault monitoring system
- fire extinguishers and fire circuits
- testing facility
- toilet/cargo smoke detectors
page 83
what are the indications of thermal expansion and use of the fire bottle on the side of the aircraft fuselage ?
separate disks, one for extinguishment release and one to indicate use
page 83
describe the approach difference between a jet and a piston engine propeller aircraft ?
- momentum (jet is heavier so changes are much slower)
- speed stability
- wing lift value
- engine response rate (acceleration/deceleration)
- slipstream effect
- power on stall speed (the prop slipstream lowers the stall speed when powering on, jet don’t have that)
page 85
explain the (low) speed control difference between a jet aircraft and a propeller driven aircraft ?
the value of drag against a speed is different which make their speed controllability different
page 86
what speed stability difference are there between a jet aircraft and a prop driven aircraft
the jet has poorer stability then prop plane
page 87
describe the difference between a jet and a piston engine propeller aircraft’s stall speed ?
the stall speed of a piston engine is lower but the range of the jet is wider
page 87
describe the differences between propeller and jet aircraft wing performance.
prop driven aircraft have better performance then jet swept wings especially when contaminated. the prop driven aircraft wing has more energised airflow on the upper surface.
page 87
what is true direction?
is the direction measured to true north
page 89
what is magnetic direction?
is the direction measured to magnetic north
page 89
what is magnetic variation ?
is the difference between true direction and magnetic direction
page 89
what is compass direction?
is the direction measured to compass north
page 89
what is compass deviation ?
is the difference between magnetic direction and compass direction
page 89
what are the lines that run from pole to pole on the earth called?
meridians of longitude
page 90
how do you measure a change of latitude?
1 Nm = 1 min therefore 60 min = 1º of latitude
page 90
what are the lines that run east west called ?
parallel of latitude
page 90
how do you measure a change of longitude ?
with the departure formula because as latitude increases longitude decreases
page 90
what is departure ?
departure = change in longitude(min) x cos latitude
page 90
what is a great circle track ?
is the shortest distance between to point
page 91
what is a rhumb line ?
is the line that cuts meridians at the same angle, also a longer distance than a great circle
page 91
what is convergency ?
is the convergency of meridians towards the poles
page 91
what is a conversion angle ?
is the angle of difference between a great circle and a rhumb line
page 92
what is chart scale ?
ratio of chart distance to earth distance
page 92
describe the doppler effect ?
is the change of frequency between the transmitted and received signal.
as you get closer the frequency circles increase and you get further the frequency of coming circles decreases
page 92
what is an airborne doppler system ?
is a self contained radio system that calculates the ground speed based on doppler effect
page 92
what is an INS/IRS ?
Inertial Navigation System, it’s a navigation system, like an internal gps without external assistance.
Inertial Reference System, is a modern INS that work with the FMS and provides actual magnetic position and heading information with reference to the FMS required position and heading
page 92
how does an INS/IRS work ?
the INS determines the initial position an give an up to date position as the aircraft accelerates in the horizontal plane on a great circle track.
component:
- accelerometer
- gyroscopes
- position computer
page 93
how does an INS/IRS find true north ?
it’s aligned to true north via gyroscopes
page 93
how does an INS/IRS find magnetic north ?
applies the stored variation the true north
page 93
What are the advantages of an INS ?
- it’s a global system
- it’s self contained
- it’s very accurate
INS with laser gyroscopes
- short warm up
- no real wander
- no precession
page 93
what are the disadvantages of an INS ?
errors that do not increase:
- shuler loop
- north alignment
errors that increase:
- incorrect position input (will cause velocity and position error)
- north alignment
Inherent system errors:
- no allowance for distance being greater at height than on the ground (not very large)
- doesn’t make allowance for the earth not being a real sphere
page 94
describe GPS
it’s Global Positioning System.
- it’s made of 24 satellites but only 21 are operative at one time.
- 6 orbital planes (each one is 3-4 satellites)
- each orbital plane is 55º to equator
- 4 satellites will always be in line of sight at any position of the earth
n1 e n2 establish LAT and LONG
n3 confirm the FIX
n4 altitude info
the GPS receiver uses the time delay between transmission and reception to calculate its distance to the satellite
page 95
what are the advantages of the GPS ?
- truly global
- high capacity use
- high redundant satellites
- built in fix confirmation (n3)
- able to be integrated into FMS
- potential to be very accurate
- ability to fly great circle tracks very accurately
- free of charge
page 95
what are the disadvantages of the GPS ?
- selective availability
- system errors
page 96
What is differential GPS ?
it’s a more accurate GPS
page 96
how does differential GPS work ?
a ground station fixes up the GPS signal and sends a more accurate signal to aircrafts within 70 nm
page 96
how is an INS/IRS better than a GPS especially for navigation information ?
INS/IRS is the only truly onboard self contained system and suffers fewer errors than the GPS
page 97
what do you know about FANS ?
future air navigation system
page 97
what is R-NAV ?
is a form of onboard area navigation aircraft equipment that uses either a basic VOR/DME systems or either position sensors
page 98
what do you know about the free flight concept ?
system under development that will allow airlines to set their own direct route
page 98
what is Decca ?
is a low frequency navigation system.
uses hyperbolic position lines. it measures the lines of equal difference in range between two beacons. to fix your position you need a minimum of three stations.
page 99
what is Omega ?
is a long range global navigation system that uses ground based beacons operating in very low frequency
page 99
what it rho rho rho Omega ?
a omega system using three stations position fixing
page 99
what is Loran C ?
long range navigation system that uses ground based beacons that operates in the low frequency band using surface waves to achieve range of more the 100 nm
page 99
describe VHF directional finding (VDF) ?
uses radio waves and does not require any additional instrument in the cockpit. the system allows ATC to provides pilots with bearing information
page 99
give the following definition QUJ, QTE, QDR, QDM
QUJ: true bearing TO the station
QTE: true bearing FM the station
QDR: magnetic bearing FM the station
QDM: magnetic bearing TO the station
page 100
what is a QGH let down ?
a VDF let down available to military
page 100
describe how a NDB/ADF works ?
a non directional beacon is a medium range radio navigation aid that send out signals(bearings) for aircraft to home to.
transmits in the 200 to 1750 kHz medium and low frequency
page 100
what is the range of the NDB ?
300nm over land, 600nm over water
page 101
what are the errors of an NDB/ADF ?
- interference form other NDB station
- thunderstorms
- night effect (ionosphere raising at night)
- coastal refraction
- mountain effect
- quadrantal error
page 101
what is and ADF beat frequency oscillator (BFO) used for ?
BFO imposes a tone onto the carrier wave to make it audible to the pilot
page 101
what is a VOR and how does it work?
a VOR is a VHF Omni Range short range navigation aid that projects 000º to 359º radials .
transmits at very high frequency band 108 to 118 MHz
page 102
what is the range of a VOR ?
line of sight propagation path below 5000ft is 60 nm 5000 to 10000 is 90 nm 10000 to 15000 is 120 nm and so on
page 103
what errors do a VOR experience ?
- equipment errors (max 5º error)
- site error (signal reflection on near object)
- propagation error (scalloping effect)
page 103
what has the furthest range VOR or NDB ?
NDB because of its surface wave propagation path. where VOR is line of sight
page 103
describe an ILS and how it works ?
is the most accurate precision approach landing system
it’s made off two beacons which guide the aircraft to land
the first one is provided by the Localiser which gives left and right on track guidance.
the second one is the Glide Slope which gives up and down on track guidance.
GS extends to 8º left and right and can be captured at 10 nm.
ILS uses 100 to 150 MHz frequency
GS uses 329 to 335 MHz frequency
page 104
what is a ILS back course approach ?
a mirror image of the localiser beam on the reciprocal runway
page 104
what errors does an ILS experience ?
- false glide slope (approaching the 150hz lobe which overlaps the 90hz lobe you will descent at twice as the 3º glide path)
- phantom signals (outside range signals cannot be relied on)
- back course approaches (would display exactly the opposite of the correct indications)
page 105
what is MLS ?
Microwave Landing System, is more accurate then ILS
page 105
how does the MLS work ?
detects the aircraft position by sweeping the signal 20º left to 20º right and back
page 106
what are the advantages of the MLS ?
- offers a curved or off center beam
- not sensitive to reflection from terrain
- has more transmitting channels
page 107
describe the DME system and how it works ?
it consist of a onboard aircraft interrogator and a ground beacon transmitter. (UHF)
The time delay between sending and receiving these pulses is converted into a range (SLANT) and distance (nm).
transmitter and receiver are correctly associated via the unique DME random pulse (jittering)
the ground transmitter re-transmits at a difference frequency 63 MHz apart from the interrogator
page 107
how is DME information used ?
VOR/DME
ILS
page 108
what error does DME experience ?
slant range error (when close to the beacon the pilot cannot get a reading)
page 108
what does radar stand for ?
radio detection and ranging
page 109
describe primary (pulse) radar and how it works
works on the reflected signal principal
primary radar uses UHF VHF
page 109
what effects the range of primary pulse radar ?
- atmospheric attenuation
- antenna power
- height of the aircraft
page 109
describe secondary (surveillance) radar and how it works /
works on the respondent-reply signal principal
page 110
describe the functions of a transponder
- code selection
- transmission function switch (STDBY, ON, ALT, TEST)
- reply/monitoring light
- ident switch
- system switch
- fault light
page 111
what are the advantages of secondary radar ?
- positive identification
- abnormal situation
- altitude ground speed reporting
- ident
page 112
how does an isoecho (weather radar) work ?
the radar aerial fitted in the nose scans 90º left and right and 15º up and down. it detects water droplets
page 112
how do you calculate cloud tops ?
60 range in ft = nm x 6080 = ft
page 113
what is AGC on weather radar ?
Automatic Gain Control.
it lowers the strength of the signal so that the closer target don’t look the brightest given false indication
page 113
on a color weather radar display, what colours represent the areas of greatest turbulence ?
thunderstorms appear as red colour, turbulence are associated with them
page 113
what is the aviation definition of height ?
distance above ground (QFE)
page 115
what is the aviation definition of altitude ?
distance above QNH or altitude above mean sea level
page 115
what is the aviation definition of flight lever ?
pressure lever above standard QNH 1013
page 115
what does ISA stand for ?
International Standard Atmosphere
page 115
what are the ICAO ISA conditions at sea level ?
15ºC, QNH 1013, ELP 2º x 1000ft
page 115
what is air pressure ?
the weight of a column of air or the gravity of air molecule
page 116
how many feet are in a millibar ?
air pressure rate of change
the rate of change in air pressure is more near the ground and less at high altitude
page 116
how many inches of mercury in a millibar ?
0.00295 in 1 hpa
page 116
what is pressure altitude ?
is the height above 1013
page 116
how do you calculate the pressure altitude actual height ?
difference between actual QNH and standard QNH multiplied by 27 (27ft x 1 hpa), then add or subtract from starting altitude.
from high to low beware below
from low to high you-re up in the sjy
page 117
why do you need to calculate the actual height of a pressure altitude ?
any difference from 1013 will give a difference between the pressure altitude and the actual altitude
page 117
what common pressure error is commonly experienced ?
barometric pressure error on the altimeter
page 117
what is ISA temperature deviation ?
the measurement of actual temperature against ISA
page 118
if you were at 33000 ft with an OAT of -45ºC what is the temperature deviation from ISA?
-45 - ( 15 - (33 x 2) ) = 6ºC
page 118
what is density ?
mass per unit volume of a substance
page 118
what is density altitude ?
is the pressure altitude corrected for temperature
page 118
what are the main influences on air density ?
- temperature
- pressure
- humidity
page 118
how does the variation of air density due to temperature effects an aircraft’s performance ?
aircraft performance decreases
page 119
what density errors are commonly experiences ?
- altitude errors
- airspeed errors
page 119
what is static pressure ?
the pressure around us
page 119
what is dynamic pressure ?
is the movement of air molecules
- by movement of a body through the air
- air flowing over a stationary object
dynamic pressure = 1/2rho x V2
page 120
describe IAS
the measurement of dynamic pressure translated into speed
page 120
describe CAS
IAS corrected for instrument and pressure error
page 120
describe EAS
is the equivalent airspeed,
is CAS corrected for compresability error
page 121
describe TAS
is the true airspeed,
is EAS corrected for density error
page 121
describe ground speed
is the speed related to ground distance travelled
is TAS plus TW or minus HW
page 121
describe LSS
Local Speed of Sound
LSS = 38.94 sq root T
T in Kelvin = 273 + ºC
page 122
how does temperature effects LSS ?
as temperature decreases LSS decreases
page 122
describe Mach number ?
Mn = TAS/LSS
Mn becomes the speed reference at high altitudes passing 26000ft
page 122
what is the main influence on mach number ?
if LSS decreases Mn increases
page 123
what happens to the indicated Mn in a long range cruise as weight decrease at the same flight level ?
Mn decreases
as weight decreases to fly at the same TAS we need a lower Mn otherwise te same will increase our TAS
page 123
What happens the CAS and IAS if you descent at constant TAS ?
they both increase
page 124
what happens to your TAS if you climb at a constant CAS, IAS ?
TAS will increase
page 124
what happens to your Mn if you climb at a constant CAS, IAS ?
Mn increase
page 124
what happens to your CAS or IAS and TAS if you fly at constant CAS into a warmer area?
IAS CAS stay the same
TAS increases
page 124
if two aircraft are flying at two different flying levels at the same Mn, which aircraft has the highest TAS/CAS(IAS) ?
the one at the lower altitude
page 125
what happens to Mn and CAS or IAS when climbing through an isothermal layer at a constant TAS?
isothermal layer is a layer of constant temperature
Mn depends on temperature therefore it will remain constant.
CAS and IAS will decrease
pag 125
what happens to CAS or IAS if an aircraft descent through an isothermal layer at a constant TAS ?
they increase
page 125
what happens to CAS or IAS an Mn if an aircraft climbs at a constant TAS through and inversion layer ?
Mn decrease (if temp increases LSS increases, if LSS increases Mn decrease) IAS CAS will decrease
page 126
what are the pressure flight instruments and how do they work ?
- ASI and MM
- ALT
- VSI
VSI and ALT measure the change in static pressure via static ports
ASI via the use of a pitot tube which measures the dynamic pressure by the difference of total pressure minus static pressure.
page 127
how does the ASI work?
the pitot tube measures the difference between total pressure and static pressure which is dynamic pressure
page 128
what are the ASI errors ?
- instrument error
- pressure error
- density error
- compressibility error
- manoeuvre error
- blocked pitot static system
page 128
how is VMO displayed on the ASI ?
a red/black striped pointer on the ASI
page 128
describe how a mach meter works ?
measures the airspeed relative to the speed of sound.
It’s a combined ASI and Altimeter.
Mn = dynamic pressure/static pressure
page 128
what errors does a Mach Meter suffer from ?
- instrument error
- pressure error (position or configuration error)
- blocked pitot static system
page 129
what are the ASI/Mach meter indications and actions for a blocked pitot and/or static probe ?
Static line blockage:
- descent they will over read
- climb they will under read
Pitot line blockage:
- descent will under read
- climb will over read
page 130
how does a pressure altimeter work ?
it measures changes in static pressure
page 130
give the definitions of the following altimeter sub scale settings.
QNH: altitude above mean sea level
QFE: this zeros the altimeter on the airfield elevation datum
QFF: QNH for actual conditions not ISA
page 130
what are the altimeter errors ?
- instrument errors
- pressure errors
- time lag error
- barometric error
- temperature/density error
- blocked static port
page 130
what are the altimeter indications and actions for a blocked static port ?
show the altitude it got blocked at
page 131
giving a temperature deviation from ISA of 36ºC the pressure altimeter will over read, under read or remain constant and why ?
the altimeter will over read because the deviation is colder than ISA
page 132
what do you know about servo assisted altimeters ?
is more accurate because it doesn’t rely on the mechanical but it’s electrically conducted bar arrangement
page 132
what is the advantages of a servo assisted altimeter ?
reduce
- instrument error
- lag error
page 132
how does a VSI work ?
expresses the rate of change in static pressure as a rate of descent or climb
page 132
what errors does the VSI suffers from ?
- lag error
- pressure error (position error)
- manoeuvre error
page 133
what type of dial display does a VSI have ?
(explain gauge)
page 133
what to you know about an IVSI ?
the inertia of the balance weight on the other side of the needle enhances a quick response to change in altitude
page 133
what are the advantages of a IVSI ?
more reliable due to immediate display
page 133
what are the disadvantages of a IVSI ?
is that the balance weight is also effected by acceleration in a turn
page 133
what are the VSI indications and actions for a blocked static port ?
the VSI will show ZERO
page 133
how is air temperature measured ?
total head thermometer
page 134
what do you know about air data computers (ADC) ?
modern aircraft feed their static and pitot line into an ADC and this data calculates can be feed to other systems like
- AP
- FDS
- FMS
- GPWS
page 134
what are the gyro flight instruments ?
- DG
- AH
- turn and slip indicator or coordinator
page 135
what is a gyroscope ?
it’s a body rotating freely in one or more direction that possess rigidity and precession
page 135
how does a gyroscope work ?
due to vacuum the gyro spins due to the rigidity the the gyro stays stable as the aircraft moves around it
page 135
what is gyroscopic wander ?
any movement away from its fixed direction is called wander which can cause inaccurate instrument readings
page 135
what is the gyroscope caging system and why is it used?
a caging system locks the gyroscope this is used to avoid toppling (stay rigid in space) once the aircraft is restarted
ex. AH
page 136
what is real wander of a gyroscope ?
occurs when the gyroscope’s spin axis moves away from its alignment in space
page 136
describe the directional indicator instrument (DG) ?
it is a gyro that displays aircraft heading
- tied gyro
- rotates around earth horizontal axis
- two gimbals
- three planes of freedom
- the axis is aligned to true north
page 136
how to do correct for apparent wander ?
by periodically realigning it (every 10-15 min)
part 137
what it transport wander ?
if a DG is aligned to true north and it’s moved east-west to another part of the globe it will be out of alignment
page 137
what errors does DG suffer ?
- system failure
- total wander errors
- ONUS (S.H.) and UNOS (N.H.)
page 137
what is the advantage of the DG over the magnetic compass ?
turning and acceleration errors
page 137
describe the air driven AH ?
primary attitude instrument that displays pitch and roll about the horizontal axis
- earth gyro
- rotates about vertical axis
- two gimbals
- three planes of freedom
- aligned to earth vertical
page 137
what errors do an AH experience ?
- turning errors
- acceleration errors
- real wander
page 138
what are the indications and actions for a failed AH ?
- low reading of the suction gauge
- possible warning flag on some instruments
page 138
describe the electrically driven AH ?
same principal as a air driven AH but it can spin faster and is more accurate because more rigid, and turning and accelerations errors are minimised
page 138
what is a servo driven attitude indicator ADI (remote AH) ?
is used in modern aircraft to display attitude informations calculated by the IRS.
the system is free of errors
page 138
describe the turn and slip (turn coordinator) indicator instrument ?
is two instrument combined:
- one measure turn
- one measure skid or skip
consist of:
- a rate gyroscope
- rotates around horizontal axis
- two panes of freedom (the gyro spin axis, yaw axis of gimbal)
- the gyro is aligned to the aircraft’s lateral axis
page 140
describe the following turn and slip indicaton
if the ball is to the left use left rudder
if the ball is to the right use right rudder
Skid = too much rudder or too little bank Slip = too little rudder or too much bank
page 140
what errors does the turn and slip indicator experience ?
- gyro system failure
- looping error (tilting)
- real wander
page 140
what is a turn coordinator ?
is an advanced development of the turn and slip indicator but is both sensitive to roll and yaw and it shows a turn as soon as the roll in begins
page 140
