Unit 2 Flashcards
Magnet
Piece of metal that attracts other metal
What are magnetic compasses used for?
used to set heading indicator prior to flight
When are the indications of a compass accurate?
ONLY in straight, level, unacelerated flight
Magnetic deviation error
diff between heading indicated by magnetic compass & airplane’s actual magnetic heading
Interference of instruments with compass
compass card used to correct
Magnetic Dip Error
tendency of compass needle to point downward in N hemisphere & upward in S hemisphere
Largest compass error
Magnet Acceleration Error
Northern hemisphere:
acceleration = turn toward N
deceleration = turn toward S
Magnetic turning error
Compass lags when turning N, leads when turning S
NOSE: North Opposite, South Exaggerated
Compass Card Oscillation Error
erratic movement of compass needle
(caused by turbulence)
Magnetic Variation
Diff between true N & magnetic N
East is least, West is best
In the Northern Hemisphere, a magnetic compass will indicate a turn toward the north if
aircraft is accelerated while on E or W heading
In the Northern Hemisphere, a magnetic compass will normally indicate initially a turn toward the west if
right turn is entered from a N heading
In the Northern Hemisphere, the magnetic compass will normally indicate a turn toward the south when:
aircraft is decelerated while on W heading
The pitot-static system is a source of pressure for which instruments?
source of static pressure for altimeter, vertical-speed indicator, airspeed indicator
Static pressure
pressure of still air (taken form static line)
Pitot pressure
total pressure (taken from pitot tube)
The pressure from the alternate static source is less or more than from the normal static?
Alternate static pressure < pressure normal static source
The pitot system provides impact pressure for which instrument?
Airspeed indicator only
Which instrument(s) will become inoperative if the static vents become clogged?
Airspeed indicator, altimeter, & vertical speed indicator
Airspeed indicator (ASI)
indicated speed at which plane is moving through the air
Dynamic pressure
diff between total pressure & static pressure
Airspeed indicator color arcs & their meaning?
- White arc: flap operating range
- Green arc: normal operating range
- Yellow arc: caution range
- Red line: never-exceed
Design manoeuvring speed VA
speed below which you can fully deflect 1 flight control 1 time in smooth air without risk of damage
Design manoeuvring speed VA
speed below which you can fully deflect 1 flight control 1 time in smooth air without risk of damage
Max speed stall safely
Does the design maneuvering speed (VA) vary with gross weight?
Yes
Indicated airspeed (IAS)
direct instrument reading obtained from ASI (uncorrected)
Calibrated airspeed (CAS)
IAS corrected for instrument errors
True airspeed (TAS)
True speed of plane through the air
CAS corrected for density altitude
What is the general rule for approx TAS if IAS is known?
add 2% to IAS for each 1,000ft of altitude
Altimeter (ALT)
measured height of plane above given level
Absolute altitude
vertical distance of plane above terrain
True altitude
actual distance above mean sea level (MSL)
Indicated altitude
read directly from altimeter
Pressure altitude
height above standard datum plane of 29.92 in. of mercury
As altitude increases, air pressure decreases
Density Altitude
pressure altitude corrected for nonstandard temperature variations
When does pressure altitude = density altitude?
At standard temperature
Does the altimeter setting change during flight?
Yes! Must re-read altimeter setting as flight progresses
What is the effect of nonstandard pressure & temp on the altimeter?
warm days altimeter indicates artificially low altitudes
pilot CANNOT adjust altimeter for temp
Which devices contain gyroscopes in the instruments?
turn, heading, attitude indicator
What are the fundamental properties of gyroscopic action?
Rigidity & Precession
What are the most important design characteristics of a gyroscope?
LARGE weight, LOW friction
Attitude indicator (AI)
depicts the attitude of the airplane (highly reliable)
Turn coordinator (TC)
emergency source of bank info → indicates direction of roll/yaw and rate of turn
Standard-rate turn
3º per sec
Inclinometer
indicated the need for rudder
Skid
Skid: rate of turn too great for the angle of bank (too little rudder)
SLIP
Slip: rate of turn too slow for angle of bank (too much rudder)
What must you do to correct for rudder?
Step on the ball
Heading indicator (HI)
instrument used in light planes as primary source of heading info
HI must be realigned with a magnetic compass every 15 min
Vacuum system:
spins gyro by drawing a stream of air against the rotor vanes to spin the rotor at high speeds
Glass cockpits
advanced avionics system replace older round-dial gauges
Electronic flight instrument displays (EFIS)
flight instrument that uses colourful, picture-like displays
Primary flight display (PFD)
integrates all flight instruments critical to safe flight into 1 screen
Attitude, heading, airspeed, altitude, vertical speed, sklip/skid condition, navigation info
Multi-function display (MFD)
not only shows primary instrumentation but can combine info from multiple systems on 1 page
Oil System
storing & circulating oil throughout internal components of engine
What are the basic functions of the engine?
lubricate, seal, clean, cool (most important)
Cowl flaps
hinged covers through which hot air is expelled
Propeller
rotating airfoil → transforms rotary power of the engine into forward thrust
Constant-speed propeller
(controllable pitch)
lets pilot select blade angle for most efficient performance
Propeller slip
diff between geometric pitch & effective pitch
Geometric pitch
theoretical distance a propeller would advance in 1 revolution if it were rotated in a solid medium
Effective pitch
actual distance propeller moves forward through air in 1 revolution (includes propeller slippage)
Propeller efficiency
ratio thrust horsepower to brake horsepower (horsepower engine is delivering to crankshaft)
depends on amount of slipage
Fixed-pitch propeller
fixed by manufacturer (cannot be changed by pilot)
Ignition system
provide electrical spark to ignite fuel/air mixture in the cylinders
(seperate from electrical system)
Magneto
engine-driven unit that uses a rotating magnet inside a coil of wire to produce electrical current
Tachometer
speed at which the engine crankshaft is rotating (RMP)
Manifold pressure (MP) gauge
indirectly indicated power output of the engine
Throttle
controls amount of fuel/air mixture that goes into engine
Induction system
process that takes outside air, mixes it with fuel, and delivers it to cylinders
Carburetor system
mixes fuel & air
When is carburetor icing most likely?
when temp are below 21ºC & humidity is above 80%
Induction system icing
icing conditions which result in loss power & potential engine failure
Impact ice
moisture-laden air freezes on elements of the induction system
(most often when ambient air is about –4ºC)
Throttle ice
water vapor in the air condenses and freezes
(happens with partially closed throttle)
Fuel vaporization icing
vaporization of fuel causes sudden cooling of the mixture
Carburetor heat
anti-icing device that preheats the air before it reaches the carburetor
(If icing detected, FULL carburetor should be immediately applied)
Outside air temp (OAT) gauge
outside/ambient air temp to calculate true airspeed & detect potential icing conditions
Mixture control
adjust fuel/air ratio to compensate for varying air densities when plane changes altitude
Fuel/air ratio
ratio between weight of fuel & weight of air entering cylinder
What is a Four-Stroke engine?
reciprocating engine converts chemical → mechanical energy in 4 strokes
Detonation
fuel/air mixture explodes instead of burning
(Caused by using LOWER octane rate than specific OR xs engine temp )
Anti-kock quality
HIGH grade = HIGH compression
(without detonating)
Correct fueling procedure:
- Attach ground wire to plane before removing cap from tank
- Ground refueling nozzle to plane
- Ground fuel truck to plane & ground
Tips to start plane in cold weather?
- Use portable heater to blow hot air into engine
- Prime cold engine at low RPM for 2-5min
Engine driven alternators (generators)
- supply current to the electrical system & maintain electrical charge on battery
Ground power units (GPUs)
provide external energy for starting
(especially during cold starts)
Bus bar
common point from which to distribute voltage throughout electrical system
Circuit breakers (fuses)
protect circuit from electrical overload
Anmeter
instrument used to monitor performance of the electrical system, specifically if generator is producing adequate supply of power (amps)
Loadmeter
shows amount of current coming from the alternator
Which color identifies the power-off stalling speed in a specified configuration?
lower limit of the green arc
How is engine operation controlled on an engine equipped with a constant-speed propeller?
The throttle controls power output as registered on the manifold pressure gauge and the propeller control regulates engine RPM.
Which instrument(s) will become inoperative if the static vents become clogged?
Airspeed indicator, altimeter, and vertical speed indicator.
What is pressure altitude?
altitude indicated when barometric pressure scale is set to 29.92
While cruising at 9,500 feet MSL, the fuel/air mixture is properly adjusted. What will occur if a descent to 4,500 feet MSL is made without readjusting the mixture?
The fuel/air mixture may become excessively lean.
Which color identifies the power-off stalling speed with wing flaps and landing gear in the landing configuration?
lower limit of the white arc
To properly purge water from the fuel system of an aircraft equipped with fuel tank sumps and a fuel strainer quick drain, it is necessary to drain fuel from the __
fuel strainer drain and the fuel tank sumps.
In the Northern Hemisphere, a magnetic compass will indicate a turn toward the north if:
aircraft is accelerated while on E or W heading
In the Northern Hemisphere, a magnetic compass will normally indicate initially a turn toward the west if:
right turn is entered from a N heading
In the Northern Hemisphere, the magnetic compass will normally indicate a turn toward the south when:
aircraft is decelerated while on W heading
The pitot system provides impact pressure for which instrument?
Airspeed indicator only
Altimeter setting is the value to which the barometric pressure scale of the altimeter is set so the altimeter indicates?
True altitude at field elevation
For internal cooling, air cooled engines are especially dependent on:
the circulation of lubricating oil
The operating principle of float-type carburetors is based on the:
difference in air pressure at the venturi throat and the air inlet
During the run-up at a high-elevation airport, a pilot notes a slight engine roughness that is not affected by the magneto check but grows worse during the carburetor heat check. Under these circumstances, what would be the most logical initial action?
Check the results obtained with a leaner setting of the mixture.
If a pilot suspects that the engine (with a fixed-pitch propeller) is detonating during climb-out after takeoff, the initial corrective action to take would be to:
lower the nose slightly to increase air speed
On aircraft equipped with fuel pumps, when is the auxiliary electric driven pump used?
In the event engine-driven fuel pump fails
An electrical system failure (battery and alternator) occurs during flight. In this situation, you would:
experience avionics equipment failure.
The basic purpose of adjusting the fuel/air mixture at altitude is to
decrease the fuel flow in order to compensate for decreased air density
Under what condition will true altitude be lower than indicated altitude?
In colder than standard air temperature.
If an aircraft is equipped with a fixed-pitch propeller and a float-type carburetor, the first indication of carburetor ice would most likely be
decrease of RPM.
With regard to carburetor ice, float-type carburetor systems in comparison to fuel injection systems are generally considered to be
more susceptible to icing.
A precaution for the operation of an engine equipped with a constant-speed propeller is to
avoid high manifold pressure settings with low RPM.
What is one procedure to aid in cooling an engine that is overheating?
Enrich the fuel mixture
What should be the indication on the magnetic compass as you roll into a standard rate turn to the right from a south heading in the Northern Hemisphere?
The compass will indicate a turn to the right, but at a faster rate than is actually occurring
Generally speaking, the use of carburetor heat tends to
decrease engine performance.
What action can a pilot take to aid in cooling an engine that is overheating during a climb?
Reduce rate of climb and increase airspeed.
If a flight is made from an area of low pressure into an area of high pressure without the altimeter setting being adjusted, the altimeter will indicate
lower than the actual altitude above sea level.
The reason a 4-cylinder reciprocating engine continues to run after the ignition switch is positioned to OFF may be a
broken magneto ground wire.
The presence of carburetor ice in an aircraft equipped with a fixed-pitch propeller can be verified by applying carburetor heat and noting
a decrease in RPM and then a gradual increase in RPM.
A turn coordinator provides an indication of the
movement of the aircraft about the yaw and roll axes.
If a flight is made from an area of high pressure into an area of lower pressure without the altimeter setting being adjusted, the altimeter will indicate
higher than the actual altitude above sea level.
What change occurs in the fuel/air mixture when carburetor heat is applied?
The fuel/air mixture becomes richer.
While cruising at 9,500 feet MSL, the fuel/air mixture is properly adjusted. What will occur if a descent to 4,500 feet MSL is made without readjusting the mixture?
The fuel/air mixture may become excessively lean.
Under what condition is indicated altitude the same as true altitude?
When at sea level under standard conditions.
You are flying an aircraft equipped with an electronic flight display and the air data computer fails. What instrument is affected?
Airspeed indicator.
