Aircraft Instruments Flashcards
How are aircraft instruments classified?
ACCORDING TO THE JOB THEY PERFORM AND THIER PRINCIPLE OF OPERATION
What are the 4 main principles of operations for aircraft instruments?
PRESSURE
GYROSCOPIC
MAGNETIC
ELECTRIC
What are the 4 ways that instrument information can be displayed?
ANALOG - DIAL OR BAR GRAPH
DIGITAL - NUMERICAL
GRAPHIC
OR ANY COMBINATION
What does EFIS stand for?
Electronic Flight Instrument System
How is the EFIS displayed and what information does it show?
A CRT OR LCD DISPLAY UNIT.
IT DISPLAYS TO THE PILOT ALPHA-NUMERIC DATA AND GRAPHIC DISPLAYS THAT REPRESENT THE AIRCRAFT INSTRUMENTS.
What are the 2 basic types of pressure instruments?
BOURDON TUBE TYPE
DIAPHRAGM OR BELLOWS TYPE
What 2 things does a Bourdon Tube measure?
HIGH PRESSURE and Temperature
(Hydraulic, Oil, Oxygen, etc)
What do Diaphragms/Bellows measure?
LOW Pressure
(Bellows provide a greater range of movement than Diaphragms)
The Pitot Static system is the source of pressure needed for what 4 instruments?
Altimeter
Airspeed
Vertical Speed
Machmeter
What is a Pitot Tube?
TUBE WITH AN INSIDE DIAMETER OF APPRX. 1/4” INSTALLED ON THE OUTSIDE OF THE AIRCRAFT. PICKS UP RAM AIR PRESSURE & DIRECTS IT TO THE INSTRUMENTS.
What are Static Ports?
SMALL HOLES ON EITHER SIDE OF THE FUSELAGE OR VERTICAL FIN OR SMALL HOLES IN THE PITOT STATIC HEAD
(sense the pressure of the still or static air)
What does the Altimeter indicate?
THE HEIGHT OF THE AIRCRAFT ABOVE SEA LEVEL
What are the 3 types of altitude?
INDICATED ALTITUDE
PRESSURE ALTITUDE
DENSITY ALTITUDE
What is Indicated Altitude?
PRESSURE ABOVE EXISTING SEA LEVEL PRESSURE.
READ DIRECTLY FROM THE INDICATOR
What is Pressure Altitude and who uses it?
THE ALTITUDE ABOVE STANDARD SEA LEVEL PRESSURE (29.92Hg)
ALL AIRCRAFT ABOVE 18K ft USE THIS SETTING.
What is Density Altitude?
A COMPENSATED ALTITUDE FOUND BY CORRECTING THE PRESSURE
ALTITUDE FOR NONSTANDARD TEMPERATURE.
What are the 2 basic types of Altimeters?
NONSENSITIVE (OLD STYLE)
SENSITIVE (3-POINTER TYPE)
What are the increments for the 3 needles on the sensitive type altimeter?
Longest Needle: 100ft
Middle (fat) Needle: 1000ft
Smallest Needle (triangle): 10,000ft
How is pressure compensated for on the sensitive altimeter?
It is done by the pilot with a Barometric-Pressure setting knob
At high altitudes, how is aircraft separation maintained?
ALL AIRCRAFT MUST PLACE THE SAME PRESSURE READING IN THE KOLLSMAN WINDOW
WHEN IS IT REQUIRED FOR ALL AIRCRAFT TO PLACE THE SAME PRESSURE READING IN THE KOLLSMAN WINDOW?
AT OR ABOVE 18,000 FT
(Pressure Altitude)
Where is the Altimeter located?
MOUNTED IN THE TOP RIGHT-HAND CORNER OF THE “CRITICAL SIX”.
When is an Encoding Altimeter used?
WHEN IN HIGH-DENSITY TRAFFIC AREAS.
WHAT INSTRUMENT IS REQUIRED ON ALL CERTIFIED AIRCRAFT EXCEPT FREE BALLOONS?
Airspeed Indicator
Where is the Airspeed Indicator located?
IN THE UPPER LEFT-HAND CORNER OF THE PANEL
What are the markings on the Airspeed Indicator and what do they mean?
RED RADIAL LINE = NEVER EXCEED
SPEED.
YELLOW ARC = CAUTION RANGE OF
SPEEDS.
GREEN ARC = NORMAL OPERATING
RANGE.
WHITE ARC = FLAP-OPERATING RANGE.
BLUE RADIAL LINE = ONE-ENGINE
INOPERATIVE BEST RATE OF CLIMB
SPEED (TWIN ENGINE AIRCRAFT)
What unit of measurement does the Airspeed Indicator indicate in?
Knots
KNOTS = _____ ________ ______ PER
HOUR.
ONE NAUTICAL MILE
ONE KNOT =____ ______ ______ PER
HOUR.
1.15 STATUTE MILES
IF AN INSTRUMENT STATIC-PRESSURE LINE BECOMES DISCONNECTED INSIDE A PRESSURIZED CABIN, WHAT WILL HAPPEN?
THE ALTIMETER WILL INDICATE A LOWER ALTITUDE.
ENGINE INSTRUMENTS SHOULD BE MARKED IN ACCORDANCE WITH WHAT?
THE INFORMATION FOUND IN THE AIRCRAFT SPECIFICATIONS OR TYPE CERTIFICATE DATA SHEETS FOR THE AIRCRAFT IN WHICH THE INSTRUMENT IS INSTALLED.
THIS INFORMATION CAN ALSO BE FOUND IN THE AIRCRAFT MAINTENANCE MANUAL OR THE AIRCRAFT FLIGHT MANUAL
WHEN AN INSTRUMENT IS INSTALLED IN AN AIRCRAFT INSTRUMENT PANEL, IT IS THE RESPONSIBILITY OF THE TECHNICIAN PERFORMING THE INSTALLATION TO ENSURE WHAT?
THE INSTRUMENT IS PROPERLY MARKED FOR THE AIRCRAFT IN WHICH IT IS BEING INSTALLED
WHAT IS A WHITE SLIPPAGE MARK PAINTED ACROSS THE BEZEL AND THE GLASS OF AN AIRCRAFT INSTRUMENT USED FOR?
TO INDICATE IF THE GLASS COVER HAS SLIPPED OR DEVIATED
WHAT DOES THE VERTICAL SPEED INDICATOR (RATE-OF-CLIMB INDICATOR) INDICATE?
INDICATES THE RATE AT WHICH THE AIRCRAFT IS CLIMBING OR DESCENDING.
THE VERTICAL SPEED INDICATOR IS A DIFFERENTIAL PRESSURE INSTRUMENT, WHICH IS THE DIFFERENCE BETWEEN WHAT?
ATMOSPHERIC PRESSURE & THE PRESSURE OF THE CHAMBER VENTED TO THE ATMOSPHERE THRU A SMALL “CALIBRATED ORIFICE”.
Where is the Vertical Speed Indicator located?
LOCATED IN THE LOWER RIGHT-HAND CORNER OF THE “CRITICAL SIX”.
What is Precession?
THE CHARACTERISTIC OF A GYRO THAT CAUSES A FORCE TO BE FELT AT A POINT 90 DEGREES IN THE DIRECTION OF ROTATION FROM THAT POINT.
What are the 2 ways that Gyroscopic instruments are operated?
PNEUMATICALLY OR ELECTRICALLY
What are 2 ways that Gyroscopic instruments are driven?
VACUUM PUMP DRIVEN OR ELECTRIC MOTOR DRIVEN.
THE KNOB AT BOTTOM OF THE ATTITUDE INDICATOR IS USED TO ADJUST FOR WHAT?
PARALLAX ERROR
The Heading Indicator (sometimes called Directional Gyro) senses what?
SENSES ROTATION ABOUT THE VERTICAL AXIS OF THE AIRCRAFT.
WHAT IS A LUBBER LINE?
THE LUBBER LINE ON A DIRECTIONAL GYRO IS USED AS A REFERENCE TO REPRESENT THE NOSE OF THE AIRCRAFT
WHAT IS A STANDARD-RATE-TURN?
3 DEGREES PER SECOND. 360 DEGREE TURN IN TWO MINUTES. 180 Deg. PER/MIN.
What is a 4 minute turn indicator?
YAW AT 1.5 DEG. PER SECOND
What is the Turn Coordinator?
AN ELECTRIC DRIVEN GYROSCOPE THAT SENSES ROLL & YAW WITH A 30 DEGREE
TILTED GIMBAL.
The magnetic compass requires ___ ____ from any aircraft source.
No power
What does the magnetic compass use for its indications?
EARTH
THE CARD WILL FLOAT AND SPIN WITH RESPECT TO THE EARTH’S MAGNETIC FIELD
What does the kerosene-like fluid in the magnetic compass do?
HELPS TO DAMPEN OSCILLATIONS AND VIBRATIONS
WHAT ARE ISOGONIC LINES?
LINES INDICATING THE ANGULAR DIFFERENCE BETWEEN THE MAGNETIC NORTH POLE & GEOGRAPHIC NORTH POLE
WHAT IS AN AGONIC LINE:
THE ONE LINE ALONG WHICH MAGNETIC & GEOGRAPHIC POLES ARE IN ALIGNMENT
(No angle - 0)
What is deviation error?
AN INACCURACY CAUSED BY MAGNETIC INFLUENCES IN THE AIRPLANE
ON THE MAGNETIC COMPASS, NO READING MAY EXCEED ___ DEGREES IN ANY HEADING.
+/- 10
What should be done after completing the front of the correction card when swinging a compass?
BE SURE TO TURN IT OVER & DATE THE CARD, PRINT YOUR NAME, SIGN IT, INCLUDE YOUR A&P #, & TOTAL TIME IN SERVICE (TTIS)
When should a swinging of the compass be done?
ANYTIME THERE IS AN INSTALLATION OR REMOVAL OF RADIO/ELECTRICAL EQUIPMENT THAT COULD AFFECT MAGNETIC DEVIATION
THE FLUX GATE COMPASS USES AN AUTOSYN SYNCHRO SYSTEM WHERE THE SYNCRO TRANSMITTER IS CONNECTED TO THE SYNCRO RECEIVER HOW?
ELECTRICALLY (via wires)
A static system pressure check is done how often and in accordance with what?
Required every 24 months
FAR 91.411 & FAR PART 43 APPENDIX E
In simple terms, how is a static system check performed?
ALLOW THE ALTIMETER TO INCREASE TO A 1,000 FT. INDICATION.
CLOSE OFF THE SYSTEM (PINCH HOSE), HOLD THIS PRESSURE IN THE SYSTEM FOR ONE MINUTE.
What do Accelerometers indicate?
CHANGES ONLY ALONG THE AIRCRAFT VERTICAL AXIS
A STALL CAN OCCUR AT ANY SPEED, BUT AT ONLY ONE _____ __ ______.
ANGLE OF ATTACK (AOA)
WHAT ARE 2 BASIC TYPES OF STALL WARNINGS?
VIBRATING REED TYPE
ELECTRIC SWITCH TYPE (most common)
What does an electric switch type stall warning look like?
METAL TAB SWITCH THAT PROTRUDES FROM THE LEADING EDGE OF THE WING AT THE STAGNATION POINT
THE ANGLE OF ATTACK SENSOR DETECTS WHAT?
THE ANGULAR DIFFERENCE BETWEEN THE RELATIVE WIND AND THE FUSELAGE CENTERLINE
What are the 2 main types of vacuum pumps?
Wet
&
Dry
WET TYPE PUMPS NEED WHAT FOR POSITIVE PRESSURE SYSTEMS?
AN OIL SEPARATOR
What type of pump is used for a Dry pump system?
A CARBON-VANE PUMP THAT WEARS AWAY AT A PREDETERMINED RATE
How often must the filter in a Dry pump system be changed?
At Annuals or as suggested by the manufacturers maintenance manual
IF USING VACUUM GYROS ON THE AIRCRAFT, WHAT MUST IT HAVE?
A SUCTION GAUGE
EXCESSIVE VACUUM IN A VACUUM SYSTEM COULD BE CAUSED BY WHAT?
AN IMPROPERLY ADJUSTED VACUUM RELIEF VALVE
How does the Horizontal Situation Indicator show that a particular function is inoperative?
Warning Flags
What circuits are the warning flags included in?
IN THE NAVIGATION (NAV), THE GYRO (HDG), AND THE GLIDESLOPE (GS) CIRCUITS.
WHAT DETERMINES THE WAY THE INSTRUMENT IS MOUNTED IN THE INSTRUMENT PANEL?
THE DESIGN OF THE INSTRUMENT CASE
How are instruments secured to the aircraft?
SOME INSTRUMENTS ARE HELD IN PLACE WITH SCREWS WHILE OTHERS ARE CLAMPED USING A SPECIAL MOUNTING RING
WHY ARE MOST ELECTRICAL INSTRUMENTS MOUNTED IN IRON OR STEEL CASES?
TO PREVENT INTERFERENCE FROM OUTSIDE MAGNETIC FIELDS
(The metal traps the lines of flux)
What must you always check when installing an instrument?
THE RUBBER PANEL MOUNTS FOR SECURITY AND WEAR
INSTRUMENT PANEL MUST ABSORB _______-AMPLITUDE, ______-FREQUENCY VIBRATIONS.
High amplitude, Low frequency
INSPECT ALL BONDING BRAIDS AND HARDWARE TO ENSURE WHAT?
THAT THEY PROVIDE THE CURRENT RETURN PATH
