Reference Books

• Pilot's Handbook of Aeronautical Knowledge(FAA-H-8083-25B). (2016). Oklahoma City, OK: United States Department of Transportation, Federal Aviation Administration, Airman Testing Standards Branch.

• Instrument Flying Handbook faa-h-8083-15B. (2012). Oklahoma City, OK: United States Department of Transportation, Federal Aviation Administration, Airman Testing Standards Branch.

• Instrument Pilot Syllabus (10001785-003). (2015). Englewood, CO: Jeppesen
• https://www.faa.gov/regulations_policies/handbooks_manuals/aircraft/amt_airframe_handbook/media/ama_ch10.pdf
• Cessna. (1976). Pilot's Operating Handbook(D1057-13). Wichita, KA: Cessna.
• Garmin. (2019). Garmin G3X Pilot's Guide. https://static.garmin.com/pumac/190-01115-00_q.pdf

Reference Multimedia

• ERAUSpecialVFR. (n.d.). Motion picture Embry-Riddle Aeronautical University. (n.d.) Retrieved from https://daytonabeach.erau.edu/.
• https://1.bp.blogspot.com/-MxqVDuUYOw0/UoejNvVaTbI/AAAAAAAABYg/o8FOD_5z-Ns/s1600/Typical+location+of+the+air+induction+and+exhaust+systems+of+a+normalizing+turbocharger+system.jpg
• https://www.championaerospace.com/wp-content/uploads/2015/06/Magneto31.jpg
• 1.bp.blogspot.com/_8U8aBVPO26Y/TPHj8Br5LkI/AAAAAAAAAGg/Rx1tUg-yYCs/s1600/C172_インダクションシステム(2).jpg.
• cessnaowner.org/wp-content/uploads/2015/05/DSCN0314-1024x768.jpg.
• Google Search, Google, www.google.com/search?q=piper arrow&safe=active&rlz=1C5CHFA_enUS806US806&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj2nYHBqtvhAhUDO60KHVkZAdgQ_AUIDigB&biw=1440&bih=740#imgdii=qVlt1FGEDFSYXM:&imgrc=7HBMk4FqeotaAM:

• www.ctsys.com/images/easyblog_articles/43/Fuel01.jpg.
• Aviation, U. (2017). Electrical system of aicraft. Retrieved from https://aviationglossary.com/loadmeter/
• Can we get flexible static wicks for our Mooneys (2017). Retrieved from https://mooneyspace.com/topic/22908-can-we-get-flexible-static-wicks-for-our-mooneys/
• https://static1.simpleflyingimages.com/wordpress/wp-content/uploads/2023/02/shutterstock_690836215-1.jpg?q=50&fit=contain&w=1140&h=&dpr=1.5
• https://defineaviation.info/wp-content/uploads/The-Magnetic-Compass-of-an-Aircraft3-604x270.jpg
• https://static.garmin.com/pumac/190-01115-00_q.pdf
• https://www.flyhpa.com/files/2013/02/2015.04.10-01.44-flyhpa-55272af302764.png
• https://cdn.shopify.com/s/files/1/0403/2205/products/G3X-Touch-AOA.jpg?v=1395849627

• Pilot's Handbook of Aeronautical Knowledge(FAA-H-8083-25B). (2016). Oklahoma City, OK: United States Department of Transportation, Federal Aviation Administration, Airman Testing Standards Branch.
• https://www.flyhpa.com/files/2011/09/2015.04.10-01.35-flyhpa-552728de3803d.jpg
• https://images.flyingmag.com/flyingma/wp-content/uploads/2021/08/30200716/httpswww.flyingmag.comsitesflyingmag.comfilesimport2014sitesallfiles_images201409G1000-fix-rotator.jpg

Reference Videos/Animations and Blogs

• ERAUSpecialVFR. (n.d.). Motion picture.
• https://www.experimentalaircraft.info/articles/aircraft-vacuum-gyro-system.php
• https://www.grc.nasa.gov/www/k-12/airplane/move.html
• https://www.youtube.com/watch?v=gCq3EjF1iZ4
• HERSTAM, J. (2023, February 11). What is a flight director & how do they work? Simple Flying. https://simpleflying.com/flight-director-guide/
• Turner, T. (2019, October 29). Glass Cockpit Partial Panel. Aviation Safety. https://www.aviationsafetymagazine.com/features/broken-glass/

Index

FAA Instrument Requirements FAR § 91.205 (d)

G

R

D

C

B

A

A

D

R

enerator/Alternator

adio (Two way capabilities)

ttitude Indicator

all (Inclinometer)

lock (Displays Hours,Minutes,Seconds) 

ltimeter (Sensitive altimeter)

ate of turn indicator

irectional Gyro (Heading indicator)

ME (Above FL240) 

For IFR flight, the following instruments and equipment are required

Instruments and equipment specified in paragraph (b) and (c) of 91.205 are also required.

Click Here 91.205 (b)(c)

Inspection Requirements

FAR § 91.409

Airworthiness directives

Altimeter and  Static Pressure system  ( 24 calendar months )

Transponder  ( 24 calendar months )

ELT (12 calendar months ) and change the battery when 1 hour accumulated use or 50% of battery life

A

V

I

A

T

E

Gyroscopic Flight Instruments

Attitude Indicator 

Heading Indicator 

Turn Coordinator 

There are two fundamental properties of a gyro:

• Rigidity in space
• Precession

• Rigidity in space refers to the principle that a gyroscope remains in a fixed position in the plane in which it is spinning.

• The reaction to this force occurs at a point that is 90° later in the direction of rotation.
• This will cause small Errors in the Instruments

Powered

Attitude Indicator and Heading Indicator are Air Vacum Driven   

Turn Coordinator is Electric driven  

In simple, The engine driven pump sucks air through the system. The air flows in from the inlet filter, normally located under your instrument panel, directly into the inlet ports on your Attitude indicator and Heading indicator. The Suction Gauge give a differential pressure measured in Inches of Mercury.

Instrument Operation  

• A small symbolic aircraft is mounted in the instrument case so it appears to be flying relative to the horizon. A knob at the bottom center of the instrument case raises or lowers the aircraft to compensate for pitch trim changes as the airspeed changes.

• Instrument Should be Up and Erect within 5 minutes. In addition, deviation no more than 5 degrees pitch and bank.
• If the Aircraft experience abrupt change in Pitch or bank may cause inaccurate readings.

• Limits in the banking plane are usually from 100° to 110°, and the pitch limits are usually from 60° to 70°. If either limit is exceeded, the instrument will tumble or spill and will give incorrect indications until realigned

Limitations / Instrument Check

Instrument Errors

Attitude indicators are free from most errors, but there may be a slight nose-up indication during a rapid acceleration and a nose-down indication during a rapid deceleration.

Turning: When initiating a turn the gyro will swing or move to the rear, again due to precession of centrifugal force against the gyro. both errors are small and will correct themselves.

• These inherent errors are small and correct themselves within a minute or so after returning to straight-and-level flight and are less than half bar width.

• Suction: When suction falls below 3 1/2 inHg, the instrument will become sluggish to move. Above 4 1/2 inHg, the attitude indicator will become more lively, and it will wear out that much sooner.  

Instrument Operation

Instrument Check

Instrument Errors

• Because of precession, caused by friction between the gyro and gimbals, the heading indicator drifts from its set position.

• The heading indicator may indicate as much as 15° error per every hour of operation. Is recommended to check it every 15 minutes.

Turn Coordinator

System Operation

Gyro Click Here

• A standard-rate turn is defined as a turn rate of 3° per second.

SLIP

SKID

Magnetic Compass

• One of the oldest and simplest instruments for indicating direction.

• A self-contain instrument that does not require electricity or any other mechanism to work.

Instrument Operation

• Has two small magnets attached to a metal float sealed inside a bowl of clear compass fluid similar to kerosene.

• Magnets are mounted to float, so they move freely and align with the Earth's magnetic field.

Instrument Check

Instrument Errors

Deviation

Variation

Magnetic Dip

Oscillation

Northerly Turning Error

Acceleration Error

An aviation maintenance technician (AMT) can minimize deviation error by performing the maintenance task known as “swinging the compass," once this procedure is complete and compass adjust. The AMT records any remaining error on a compass correction card like and places it in a holder near the compass.

Variation

Oscillation

• Oscillation is caused by fluctuation of the compass during turbulence.

Magnetic Dip

• Earth's Magnetic Fields are located deep inside the planet.
• This will create the tendency of the compass to point down. The dip angle increases in a downward direction as you move towards the Magnetic North Pole and increases in an upward direction as you move towards the Magnetic South Pole.

Northerly Turning Error

• The center of gravity of the float assembly is located lower than the pivotal point.  As the airplane turns, the force that results from the magnetic dip causes the float assembly to swing in the same direction that the float turns.  The result is a false northerly turn indication.

U

N

O

S

Remember

Undershoot

North 

Overshoot

South

• Stop Turn = Latitude +/- half Bank Angle

General rule:

Acceleration / Deceleration Error

A

N

D

S

Decelerate 

North

South 

Remember

Pitot Static Instruments

• Altimeter                Airspeed Indicator    Vertical speed indicator

• The pitot-static system is a combined system that utilizes the static air pressure (static port) and the dynamic pressure (pitot tube) due to the motion of the aircraft through the air.  

The pitot tube is utilized to measure the total combined pressures that are present when an aircraft moves through the air. Called dynamic pressure or ram air pressure

Pitot Tube

Click Here

Static Port

Click Here

Measure the static pressure, also known as ambient pressure, Located where th​ere's almost no Interference with Air surround for accuracy.

• These combined pressures are utilized for the operation of the airspeed indicator (ASI), altimeter, and vertical speed indicator (VSI).

• Uses ram air pressure from the pitot tube and the static pressure from the static port.

• Displays airspeed change in Knots.

A diaphragm receives ram air coming from the pitot tube, then expands or contracts against the static pressure to display the aircraft's airspeed.

Types Of Airspeeds

Indicated Airspeed

C​alibrated Airspeed

Equivalent Airspeed

True Airspeed

Ground Speed

As a pilot you need to become familiar with the different types of airspeed.

Indicated Airspeed

Calibrated Airspeed

• C​alibrated airspeed (CAS)- is indicated airspeed corrected for Instrument installation.

• Manufacturers attempt to keep airspeed errors to a minimum.

True Airspeed

• True airspeed (TAS)- calibrated airspeed corrected for altitude and nonstandard temperature.

• At sea level on a standard day, CAS is equal to TAS.

Ground Speed

• True airspeed adjusted for wind, actual speed of the airplane over the ground.

• Ground airspeed decreases with a headwind and increases with a tailwind.

Mach Speed

• Mach is the ratio of the aircraft true airspeed to the speed of sound.
• Example: .8 Mach = 80% of the speed of sound

Instrument Check

Instrument Error

V-Speeds and Color Codes

V-Speeds

Additional V-Speeds

V-Speeds Color Codes

White arc:
flap operating range

Green arc: normal operating range

Yellow arc: “caution range” 

Red line:
never exceed speed

Vertical Speed Indicator

Indicates whether the aircraft is climbing, descending, or in level flight. The rate of climb or descent is indicated in feet per minute (fpm). Uses information only from the Static Port.

System Operation

Displays two different types of information:

• Rate Information
• Trend information.

Trend information shows an immediate indication of an increase or decrease in the aircraft’s rate of climb or descent.

It contains a diaphragm with connecting linkage and gearing to the indicator pointer inside a case.

The inside of the diaphragm is connected directly to the static line of the pitot-static system.

Calibrated Leak

The area outside the diaphragm, which is inside the instrument case, is also connected to the static line but through a restricted orifice (calibrated leak).

If the pitch attitude is held constant, the needle stabilizes after a short period (6–9 seconds) and indicates the rate of climb in hundreds of fpm. The time period from the initial change in the rate of climb, until the VSI displays an accurate indication of the new rate, is called the lag.

Instrument Check

Before engine start,​ the VSI should read 0. If not, use the reading as it is level.

Instrument Error

Sudden or abrupt changes in aircraft attitude cause incorrect instrument readings as the air flow fluctuates over the static ports. Delay from 6-9 seconds.

Pitot System Blockage

Pitot Tube Blockage

• Airspeed: If the pitot tube is clogged but drain hole is open, Indicated airspeed drops slowly to zero because of ram air is no longer able to enter the pitot system. Air already in the system vents through the drain hole, and the remaining pressure drops to ambient (outside) air pressure.

• If the pitot tube ram pressure hole and drain hole become obstructed, the ASI operates like an altimeter as the aircraft climbs and descends.

• Altimeter and VSI will continue working.

Static Port Blockage

If the static port block but pitot is clear:

• The Airspeed Indicator is inaccurate because of the trapped static pressure inside the case.  

• The Altimeter freeze at the altitude where the blockage occurred.

• The VSI will indicate zero due to static pressure being vented through the calibrated leak

Static Port Blockage

If the static port block but pitot is clear:

• The Airspeed Indicator is inaccurate because of the trapped static pressure inside the case.  

• The Altimeter freeze at the altitude where the blockage occurred.

• The VSI will indicate zero due to static pressure being vented through the calibrated leak

Using the Alternate Static Source

Opening the alternate static source introduces static pressure from the flight deck into the system. Flight deck static pressure is lower than outside static pressure.

When the alternate static source pressure is used, the following instrument indications are observed:

• The altimeter indicates a slightly higher altitude than actual.

• The Airspeed Indicator indicates an airspeed greater than the actual airspeed.

• The VSI shows a momentary climb and then stabilizes if the altitude is held constant.

Altimeter

Instrument that measures the height of an aircraft above a given pressure level. ​

A sealed Aneroid wafers, with internal pressure of 29.92,  is the main component of the altimeter. These wafers are free to expand and contract with changes to the static pressure.

What happens when the airplane climb or descend?

• A higher static pressure presses down on the wafers and causes them to collapse. A lower static pressure (less than 29.92 "Hg) allows the wafers to expand.

A mechanical linkage connects the wafer movement to the needles, which translates compression of the wafers into an increase or decrease  in altitude

Types of Altitudes

Indicated Altitude

P​ressure Altitude

Absolute Altitude

Density Altitude

True Altitude

Altitude is vertical distance above some point or level used as a reference. There are as many kinds of altitude as there are reference levels from which altitude is measured, and each may be used for specific reasons.  

Indicated Altitude

Altitude read directly from the altimeter (uncorrected) when it is set to the current altimeter setting.

Pressure Altitude

Pressure altitude is the height above a standard datum plane (SDP), which is a theoretical level where the weight of the atmosphere is 29.92 "Hg (1,013.2 mb) as measured by a barometer. ​

Formula: ( Standard Pressure - Current Pressure ) X 1000 +/- Field Elevation

Absolute Altitude

The vertical distance of an aircraft above the terrain, or above ground level (AGL).

​Density Altitude

Pressure altitude corrected for variations from standard temperature. When conditions are standard, pressure altitude and density altitude are the same. As the density of the air increases (lower density altitude), aircraft performance increases. Conversely, as air density decreases (higher density altitude), aircraft performance decreases. 

In a sense, it's the altitude at which the airplane "feels" it's flying.

• Formula: Density altitude = Pressure altitude + (OAT-ISA) *120

True Altitude

True altitude is the actual elevation above mean sea level.

Altimeter Check

• When the altimeter setting is set to 29.92'' Hg, it reads pressure altitude.
• When the local altimeter setting is set, there is no more than 75 feet difference with the field elevation

Altimeter Error

• Mechanical error:

  • A preflight check to determine the condition of an altimeter of setting the barometric scale to the local altimeter setting. The error should not be above 75 ft.

There are two types of errors

• Altimeter Setting:

  • It occur when the altimeter is not adjust to local altimeter setting to compensate for nonstandard pressure.

  • High to low look at below

  • Low to high you are in the sky.

Primary Flight Display (PFD)

Primary Flight Display (PFD) that features a horizon, airspeed, attitude, altitude, vertical speed, heading, and course deviation information.

Airspeed

Altimeter

Vertical Speed Indicator

Attitude Indicator/Turn Coordinator

Heading Indicator

Synthetic Vision

• Synthetic Vision depicts a forward-looking attitude display of the topography immediately in front of the aircraft, and is shown on the PFD.
   
• The depicted imagery is derived from the aircraft attitude, heading, GPS three-dimensional position, and databases of terrain, obstacles, and other relevant features.

• Loss of any of the required data, including temporary loss of the GPS signal, will cause Synthetic Vision to be disabled until the required data is restored.

The following Synthetic Vision enhancements appear on the PFD:

 Pathways

 Flight Path Marker  

  Traffic Display

  Airport Signs

  Zero-Pitch Line

  Obstacle Alerting

  Terrain Alerting

  Runway Display

  No Reference

Attitude and Heading Reference System (AHRS)

• The Attitude and Heading Reference System (AHRS) performs attitude, heading, and vertical acceleration calculations with help from the GPS, magnetometer, air data through its internal sensors

• Attitude and heading information are updated on the PFD, while the AHRS receives appropriate combinations of information from the external sensor inputs.

How do we get information on the PFD

• The AHRS sends attitude information to the PFD in order to generate the pitch and bank information of the attitude indicator.
   
• The heading information is derived from a magnetometer that senses the earth’s lines of magnetic flux.

• This information is then processed and sent out to the PFD to generate the heading display

Attitude Indicator

•  The attitude indicator receives its information from the  AHRS.

• Information is displayed over a virtual blue sky and brown ground with a white horizon line, that spans the entire width of the PFD.

• The horizon line is part of the pitch scale. Pitch markings occur at 2.5˚ intervals through all pitch ranges.  

The Attitude Indicator displays

• Pitch

• Slip/Skid

• Roll

• Angle of bank is indicated by the position of the pointer on the roll scale.

• Pitch indicated by the yellow symbolic aircraft on the pitch scale

Horizontal Situation Indicator (HSI)

• The current track is represented on the HSI by a magenta triangle and dashed line. The HSI also presents course deviation, bearing, and navigation source information.

• The heading indicator receives information from the magnetometer, which feeds information to the AHRS unit and then to the PFD.

Lubber line

Current track indicator

Navigation source

Heading bug

Course pointer

CDI

Rotating compass rose

To/From indication

 Aircraft symbol

Lateral deviation scale

Course deviation & to/from indicator

Air Data Computer (ADC)

• The pilot receives the airspeed, altitude, and altitude trend data on the FDC through the ADC.

• The pitot static inputs are received by an ADC.

• The ADC computes the difference between the total pressure and the static pressure and generates the information necessary to display the airspeed on the PFD.

But how exactly?

• Altitude information from static pressure,  does not enter a diaphragm.

• The ADC computes the received barometric pressure and sends a digital signal to the PFD to display the proper altitude readout

Airspeed Indicator

• The Airspeed Indicator, on the left side of the PDF, displays airspeed on a rolling number gauge using a moving tape.

• The true airspeed (TAS) is displayed in knots below the Airspeed Indicator.

• The numeric labels and major tick marks on the moving tape are marked at intervals of 10 knots.

• The actual airspeed is displayed inside the black pointer

Altimeter

• The altimeter is located on the right side of the PFD.

• As the altitude increases, the larger numbers descend from the top of the display tape, with the current altitude being displayed in the black box in the center of the display tape.

• The altitude is displayed in increments of 20 feet

Vertical Speed Indicator

(VSI)

• The VSI is displayed to the right of the altimeter tape.

• The Vertical Speed Indicator displays the aircraft's vertical speed using a non-moving tape labeled at 500, 1,000, and 2,000 fpm, with minor tick marks every 100 feet up to 1,000 fpm.

The current vertical speed is displayed using a white arrow along the tape.

PFD Failures

• A PFD failure is not consist an emergency because the PFD screen will trigger a reversion mode that takes over the MFD

How to recognize PFD Failures

• Loss of GPS Position

• AHRS/ADC Failure

• Reverse Mode

Loss of GPS Position

• A blinking red question mark will appear over the airplane icon on the map.

• The ‘Lost Satellite Reception’ message will display. 

• Any GPS dependent data fields will not be available

click here

AHRS/ADC Failure

click here

• An AHRS failure is indicated by red “X”s over the affected flight instruments and a loss of the horizon line on the PFD

• The AHRS provides attitude information while the ADC gives data like airspeed, altitude and vertical speed.

• When the AHRS and/or ADC fail, the pilot should refer to standby instruments.

click here

• An AHRS failure also causes power loss to the Magnetometer, thus the magnetic heading indications are no longer displayed on the HSI and a red “X” appears over the current heading indication.

• Use the DTK and TRK numbers from the GPS for direction.

• The ADC depends on traditional pitot/static input.

Reverse Mode

• In a two display system, in the event of a PFD failure, the MFD goes into reversionary mode, and the autopilot is disengaged.

• If the MFD fails, the PFD goes into reversionary mode and the autopilot continues to function

Failure Of The External Gps Navigation Source

click here

If the external GPS navigation source fails, the system reverts to the internal GPS navigation source and ‘REV’ is shown in yellow in the upper left corner of the Data Bar as well as the lower left quadrant of the HSI.

If the external GPS navigation source fails, the system reverts to the internal GPS navigation source and ‘REV’ is shown in yellow in the upper left corner of the Data Bar as well as the lower left quadrant of the HSI.

Features

• The MFD is used primarily for navigation display, and together with a primary flight display (PFD

• Many MFDs allow pilots to display their navigation route, moving map, weather radar, NEXRAD, ground proximity warning system, traffic collision avoidance system, and airport information on the same screen.

• If the PFD fails, its information will automatically appear on the MFD, and the autopilot can still be used.

Map Display

• A moving map using Global Positioning System (GPS) navigation with the aircraft position displayed.
  
   
• MFD and display maps provide a high level of situational awareness; pilots can Improve safety by flying more informed and aware.

Operation

• Automation is playing a key role in the aviation industry by controlling the flight management systems of the aircraft.

• It works by sending signals to the flight control system. The pilot inputs what type of mode they want, like a heading or an altitude hold mode.

Flight Director

• The flight director (FD) is an element of a plane's automatic flight control system.
   
• The flight director function provides pitch and roll commands to the pilot and autopilot, which are displayed on the PFD. With the flight director active, the aircraft can be hand-flown to follow the path shown by the Command Bars.

Command Bars

• Most traditional flight director display is the command bar layout (sometimes called the "v-bar").
   
• Command bars are a set of two triangular lines that match the shape of the airplane symbol on the primary flight display or attitude indicator.

Purpose of Command Bars

• The command bars move up, down, left, and right as a guide for the flying pilot to match and fly the path that has been selected in the flight management system.
   
• When the autopilot is engaged, the pitch and roll servos follow the flight director's commands during all turns, level-offs, and descents.

• Upon activation of the flight director, Command Bars are displayed in magenta on the PFD.
   
• If the attitude information being sent to the flight director becomes invalid or unavailable, the Command Bars are removed from the display