Airplane Systems Flashcards
How are the flight controls operated?
Manually actuated through rods and cables. Control wheel actuates the ailerons and elevator, rudder pedals accurate the rudder.
What type of trim systems are in the airplane?
Both rudder and elevator trim are equipped in the airplane, both manually actuated.
What are flaps, and what is their function?
Movable panels on the inboard trailing edges of the wings which extend downward into the flow of air beneath the wings to increase both lift and drag. Their purpose is to permit a slower airspeed and a steeper angle of decent during landing.
Describe the Piper’s wing flap system.
The flaps are extended with a pull handle with three possible settings, 10, 25 or 40 degrees.
What instruments operate from the pitot/static system?
Altimeter, Vertical Speed Indicator (VSI), and Airspeed Indicator
How does the altimeter work?
Aneroid wafers inside the altimeter expand and contract as atmospheric pressure changes.
A pressure altimeter is subject to what limitations?
Non-standard pressure and temperature variations.
How do you determine indicated altitude?
Read it directly from the altimeter (set with current altimeter setting)
How do you determine pressure altitude?
Read from the altimeter with a pressure setting of 29.92”.
What is “true altitude”?
The aircrafts height above sea level (MSL).
What is “density altitude”?
Pressure altitude corrected for non standard temperature variation. Related to the aircrafts takeoff, climb and landing performance.
What is “absolute altitude”?
Aircrafts vertical distance above the terrain.
How does the airspeed indicator work?
It measures the difference between the impact pressure at the pitot head and the atmospheric pressure at the static source.
What are the limitations of the airspeed indicator?
It needs proper flow of air into the pitot static system.
The airspeed indicator is subject to what errors?
Position error - the slipstream causing disturbances at the static port preventing the atmospheric pressure from being read.
Density error - Changes in altitude and temperature are not compensated for in the instrument.
Compressibility error - caused by the packing of air into the pitot tube at high speeds, resulting in higher than normal indications.
What is “true airspeed”?
Speed of the airplane in relation to the air mass in which it is flying.
What is “indicated airspeed”?
Speed of the airplane read directly from the airspeed gauge.
What is “calibrated airspeed”?
Airspeed reading corrected for position and instrument errors.
What is “equivalent airspeed”?
Calibrated airspeed corrected for the adiabatic compressible flow for the particular altitude.
What is the white arc on the airspeed gauge?
Flap operating range
What is the green arc on the airspeed gauge?
Normal operating range
What is the yellow arc on the airspeed gauge?
Caution range (smooth air only)
What is the red line on the airspeed gauge?
Vne , Maximum operating speed.
What is V A speed?
Maneuvering speed (131 mph)
What is V LE?
Maximum gear extension speed (150 mph)
What is V X?
Best angle of climb speed (96 mph *gear up)
What is V Y?
Best rate of climb speed (100 mph *gear up)
How does the Vertical Speed Indicator work?
Pressure differential with a calibrated leak.
How does the Vertical Speed Indicator work?
Pressure differential with a calibrated leak.
What are the limitations of the VSI?
It is not accurate until the aircraft is stabilized. Sudden or abrupt changes in altitude will cause erroneous readings.
Which instruments contain gyroscopes?
Turn coordinator, heading indicator, and the attitude indicator.
What are the two fundamental properties of a gyroscope?
Rigidity in space and precession
What sources power the gyroscopic instruments in the airplane?
Attitude indicator - vacuum
Heading indicator - vacuum
Turn coordinator - electrical
How does the vacuum system operate?
Air is sucked through a filter, then through the vacuum instruments (attitude and heading indicator), through the pump and then overboard. A relief valve regulates the pressure.
How does the attitude indicator work?
The gyro is mounted on a horizontal plane and depends on rigidity in space for operation. The fixed gyro remains in a horizontal plane as the airplane is pitched and banked about its axis, indicating the attitude of the airplane relative to the horizon.
What are the limits of an attitude indicator?
Pitch and bank limits depend upon the make and model of the instrument. Banking limits are usually around 100 degrees, pitch limits are usually around 60 - 70 degrees. If either limit is exceeded the instrument will tumble or spill giving incorrect indications until reset.
The attitude indicator is subject to what errors?
Slight nose up indication during rapid acceleration, slight nose down indication during rapid deceleration. May get a slight pitch and bank angle error after a 180 degree turn, which should correct itself within a minute or so.
How does the heading indicator operate?
Using the principle of rigidity in space the rotor turns in a vertical plane. The airplane revolves around the vertical axis and the compass card shows heading information.
What are the limitations of the heading indicator?
The instrument may tumble after reaching more than 55 degrees of pitch or bank rendering it unusable until it is reset.
What error is the heading indicator subject to?
Because of precession, caused by friction, the heading indicator will drift from a heading to which it is set. The indicator may indicate as much a 15 degrees of error per hour.
How does the turn coordinator operate?
It uses precession to indicate direction and approximate rate of turn. The slip/skid indicator is a liquid filled tube with a ball that reacts to centrifugal force and gravity.
What information does the turn coordinator provide?
It shows the yaw and roll of the aircraft around the vertical and longitudinal axis. The miniature airplane indicates direction of turn as well as rate of turn. When aligned with the turn index, it represents a standard rate turn of 3 degrees per second. The inclinometer of the coordination of aileron and rudder. The ball indicates whether the airplane is in coordinated flight or is in a slip or skid.
What will the turn indicator indicate when the aircraft is in a skidding or a slipping turn?
Skid - the ball will be to the outside of the turn; too much rate of turn to the amount of bank.
Slip - the ball will be on the inside of the turn; not enough rate of turn for the amount of bank.
How does the magnetic compass card work?
Magnetized needles are attached to a float assembly around which is mounted a compass card. The needles align themselves parallel to the earths magnetic field. The float assembly is housed in a bowl filled with kerosene.
What limitations does the magnetic compass have?
The float in the compass can rotate and tilt up to approximately 18 degrees of bank. At steeper angles the compass indications are erratic and unpredictable.
What are the various compass errors?
Oscillation -erratic movement caused by turbulance or rough control input
Deviation - caused by electrical and magnetic disturbances in the aircraft.
Variation - angular difference between true and magnetic north; reference isogonic lines of variation.
Dip Errors - caused by: a. Acceleration - on east/west headings, when accelerating the compass shows a turn to the north, and when decelerating a turn to the south Accelerate North Decellerate South
b. Northerly turning error - the compass leads in the south half of the turn, and lags in the north half.
What equipment would be considered hydraulic on this aircraft?
a. Retractable landing gear system
b. Wheel braking system
c. Nose gear shock strut
What provides hydraulic power to the landing gear system?
An electrically driven hydraulic pump provides hydraulic power to the landing gear system. The pump is located behind the passenger seats, on the right side of the aircraft.
Describe the landing system on the Piper.
The landing gear system is a tricycle-type system using two main wheels and a steerable nose wheel. All three wheels have shock absorption provided by an air/oil shock strut.
How is the landing gear extended and retracted?
An electrically driven hydraulic pump provides pressure to a hydraulic actuator which enables landing gear extension and retraction. A pressure switch starts and stops the pump and the direction of flow is controlled by the landing gear lever.
How is the gear locked in the down position?
Mechanically.
How is the hear locked in the up position?
Using positive “up” pressure which is constantly maintained by the pump and pressure switch.