Flight Instruments Flight Instruments Overview Understanding will increase

Flight Instruments Overview • Understanding will increase ability to safely utilize the instruments •

Pitot-Static System • Consists of Three Instruments and Related Components: • Air Speed Indicator

Instrument Locations © 2015 Coast Flight Training. All Rights Reserved.

Pitot-Static System • Uses pitot tube to sense total air pressure (dynamic + static)

Altimeter • Only instrument to show altitude • Most vital • Uses an aneroid

© 2015 Coast Flight Training. All Rights Reserved.

Types of Altitudes • Indicated: Read off the altimeter • Pressure: Altitude above the

Pressure Altitude • Indicated Altitude when Kollsman Window set to 29. 92 © 2015

Calculating Pressure Altitude • To calculate pressure altitude: • PA = field elevation +

Density Altitude • Density of a medium is affected by the temperature • Think

Calculating Density Altitude • To calculate Density Altitude: • DA = PA + (120

Hazards of Pressure • High to low, look out below • Go from High

Hazards of Pressure © 2015 Coast Flight Training. All Rights Reserved.

Hazards of Temperature • Hot to cold, look out below • Go from Hot

Hazards of Temperature © 2015 Coast Flight Training. All Rights Reserved.

Hazard Remedies • Update altimeter settings frequently as practical through nearest weather or controller

Vertical Speed Indicator • Shows a climb or descent rate • Instrument Relies upon

Vertical Speed Indicator • The case contains a diaphragm connected directly to the static

VSI Instrument Check • Should indicate 0 before flight • Stuck on different indication?

Airspeed Indicator • Utilizes both the pitot tube and the static port • Supplies

Airspeed Indicator • The case contains a diaphragm connected to the pitot (ram air)

Types of Airspeed • Indicated: Direct from instrument. No compensation for errors (KIAS) •

Airspeed Indicator Markings • White Arc: Flap Operating Range • Green Arc: Normal Operating

Airspeed Limitations • VSO – Stall Speed (Flaps Extended) • VS 1 – Stall

Socrative Short Answer • VSO – 45 • VS 1 – 50 • VX

Airspeed Instrument Check • Should read 0 or slightly moving in a strong headwind

Pitot Static Errors • If instruments don’t agree, assume error • Two fail-safes: •

Blocked Static System • Altimeter Stays Frozen • VSI remains zero as it cannot

Blocked Pitot Tube • Airspeed Indicator reads 0 • Land as soon as practical

Blocked Pitot Tube Drain Hole • Not applicable to Piper, but possible in Cessna

The Pitot Static Mast • Incorporates the Pitot Tube and Static Ports all-in-one •

Gyroscopic Principles • Rigidity in Space • Newton’s First: Object at rest stays at

Gyroscopic Power • Powered by electrical system • Driven by air pressure from a

Vacuum System • Consists of Two Instruments and Related Components: • Attitude Indicator •

Attitude Indicator • Provides Pitch and Bank information • Gyro spins on a horizontal

Attitude Indicator Check • Should be aligned within 5 minutes • Adjust the miniature

Heading Indicator • Heading information without the nuisance of compass errors • Gyro stays

Heading Indicator Check • Align to magnetic heading every 15 minutes and at beginning

Electrical Gyroscopic Instruments • One Instruments is powered by Electricity supplied by the Battery:

Turn Coordinator / Slip-Skid Indicator • Instrument relies on controlled precession in order to

How does the TC Work? • Uses principle of precession • Yaw from turn

Skidding vs. Slipping • Skidding Turn • Nose is yawed in the direction of

Turn Coordinator Check • Checked while taxiing • Airplane indicate a turn in the

Magnetic Instruments • One magnetic compass • Affected by the earth’s magnetic fields ©

Magnetism • Magnet is a piece of metal containing iron that has a north

Compass Errors - Variation • The difference between true and magnetic north • Aeronautical

Compass Errors - Deviation • Any error caused by a magnetic field other than

Magnetic Dip • Occurs when lines of flux dip into the earth over the

Northerly Turning Error • Undershoot North • Overshoot South • UNOS © 2015 Coast

Acceleration Error • On an East or West Heading • Acceleration indicates a turn

Oscillation Error • Combination of all the errors results in small movements, or swings

Digital Flight Instruments • Newer Aircraft include a PFD and MFD • Primary Flight

PFD Turn Coordinator VSI Airspeed Altitude Heading © 2015 Coast Flight Training. All Rights

MFD © 2015 Coast Flight Training. All Rights Reserved.

Required Instruments for Flight – 91. 205 • Changes for day and night •

ELT Requirements – 91. 207 • Batteries to be replaced: • 1 hour of

Inoperative Instruments – 91. 213 • Does an MEL Exist? • May be without

References • Pilot’s Handbook of Aeronautical Knowledge • Federal Aviation Regulations © 2015 Coast

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Flight Instruments

Flight Instruments Overview • Understanding will increase ability to safely utilize the instruments • Three Categories: • Pitot-Static • Gyroscopic • Magnetic © 2015 Coast Flight Training. All Rights Reserved.

Pitot-Static System • Consists of Three Instruments and Related Components: • Air Speed Indicator • Altimeter • Vertical Speed Indicator • All about pressures © 2015 Coast Flight Training. All Rights Reserved.

Pitot-Static System • Uses pitot tube to sense total air pressure (dynamic + static) • Static port to sense the static pressure within the dynamic flow © 2015 Coast Flight Training. All Rights Reserved.

Altimeter • Only instrument to show altitude • Most vital • Uses an aneroid wafer to hold ISA pressure • Senses the difference between the outside static pressure and the pressure in the aneroid wafer • Difference is transmitted through gears to indicate altitude above ISA © 2015 Coast Flight Training. All Rights Reserved.

Types of Altitudes • Indicated: Read off the altimeter • Pressure: Altitude above the Standard Datum Plane (ISA) • Density: Pressure altitude corrected for variations in temperature • True: Altitude above sea level (MSL) • Absolute: Altitude above ground (AGL) © 2015 Coast Flight Training. All Rights Reserved.

Calculating Pressure Altitude • To calculate pressure altitude: • PA = field elevation + (29. 92 – altimeter setting) x 1000 Note: Elevation refers to physical height above sea level; it can be an altitude in flight © 2015 Coast Flight Training. All Rights Reserved.

Density Altitude • Density of a medium is affected by the temperature • Think of molasses: is it harder or easier when it is warm? • Density of Air has a direct effect on: • Lift • Prop Efficiency • Engine Power Output • The 3 H’s: • High • Hot • Humid © 2015 Coast Flight Training. All Rights Reserved.

Calculating Density Altitude • To calculate Density Altitude: • DA = PA + (120 x (OAT °C– ISA temperature °C)) Note: ISA refers to the temperature it should be at the local altitude under standard temperature conditions. Example, sea level = 15°C, 6000 feet = 3°C. (use the temperature lapse rate of 2°C per 1000’ increase in altitude) © 2015 Coast Flight Training. All Rights Reserved.

Hazards of Pressure • High to low, look out below • Go from High to Low pressure • Difference between static and reference pressure in the wafer becomes larger and causes an increase in altitude • The pilot will view this disturbance and descend which places him at a lower true altitude and consequently, a lower absolute altitude © 2015 Coast Flight Training. All Rights Reserved.

Hazards of Temperature • Hot to cold, look out below • Go from Hot area to Cold area • Same pressure sensed by the altimeter will occur at a lower true altitude • Places the airplane at a lower absolute altitude • The atmosphere compresses (contracts) when cold © 2015 Coast Flight Training. All Rights Reserved.

Hazard Remedies • Update altimeter settings frequently as practical through nearest weather or controller • Don’t forget: 1” Hg variation = 1000 feet difference. • Not easily noticeable in flight because the pilot steadily decreases/increases true altitude while the altimeter is held constant • Check altimeter prior to flight: 75 feet © 2015 Coast Flight Training. All Rights Reserved.

Vertical Speed Indicator • Shows a climb or descent rate • Instrument Relies upon static pressure and is used to sense a change in pressure • Compares instantaneous reference of static pressure within a diaphragm to a delayed reference of static pressure within the case • Trend information: Initial indication can be used to make minor corrections during flight • Rate Information: Shows a stabilized rate of change in altitude © 2015 Coast Flight Training. All Rights Reserved.

Vertical Speed Indicator • The case contains a diaphragm connected directly to the static line • The case is connected to the static line through a calibrated leak © 2015 Coast Flight Training. All Rights Reserved.

Airspeed Indicator • Utilizes both the pitot tube and the static port • Supplies two pressures: Ram and Static • References the two against each other to show difference • Difference is read in Knots • Most susceptible to blocks, consider a pitot tube cover © 2015 Coast Flight Training. All Rights Reserved.

Types of Airspeed • Indicated: Direct from instrument. No compensation for errors (KIAS) • Calibrated: KIAS corrected for instrument installation error (KCAS) • Equivalent: KCAS corrected for compressibility effects (EAS) • True Airspeed: EAS corrected for temperature and altitude (TAS) • Groundspeed: Speed above the ground (GS) • Boat Analogy © 2015 Coast Flight Training. All Rights Reserved.

Airspeed Indicator Markings • White Arc: Flap Operating Range • Green Arc: Normal Operating Range • Yellow Arc: Cautionary Range (Smooth air only) • Red Line: Never Exceed Speed © 2015 Coast Flight Training. All Rights Reserved.

Airspeed Limitations • VSO – Stall Speed (Flaps Extended) • VS 1 – Stall Speed (Normal Condition) • VX – Best Angle of Climb • VY – Best Rate of Climb • VFE – Flap Extension Speed • VA – Maneuvering Speed • VNO – Normal Operating Limit • VNE – Maximum Structural Cruising Speed © 2015 Coast Flight Training. All Rights Reserved.

Airspeed Instrument Check • Should read 0 or slightly moving in a strong headwind • Checked for function on the takeoff roll • Abort takeoff if no indication on takeoff roll © 2015 Coast Flight Training. All Rights Reserved.

Blocked Static System • Altimeter Stays Frozen • VSI remains zero as it cannot sense a differential • Airspeed Indicator will give inaccurate readings • Will act as an altimeter • Why is this dangerous? • Think too fast on approach, inducing a stall © 2015 Coast Flight Training. All Rights Reserved.

Gyroscopic Principles • Rigidity in Space • Newton’s First: Object at rest stays at rest • Allows a basketball player to spin a ball on the tip of his finger • Spin up a gyro, use it as a reference to identify deviations from the original rotational plane • Precession • Turning/Tilting characteristic • Force applied, realized 90 degrees in the direction gyro is spinning • Friction/External Forces can cause a gyro to wander from original location © 2015 Coast Flight Training. All Rights Reserved.

Vacuum System • Consists of Two Instruments and Related Components: • Attitude Indicator • Heading Indicator (Directional Gyro) • All about spinning wheels © 2015 Coast Flight Training. All Rights Reserved.

Attitude Indicator • Provides Pitch and Bank information • Gyro spins on a horizontal plane • Gyro moves in the roll / pitch axes and attached to a card that faces the pilot • Card has horizon, pitch and bank information on it • Plane is really moving around the gyro © 2015 Coast Flight Training. All Rights Reserved.

Attitude Indicator Check • Should be aligned within 5 minutes • Adjust the miniature airplane to the horizon from your POV • 5 degrees of difference • A note about pendulous vanes © 2015 Coast Flight Training. All Rights Reserved.

Heading Indicator • Heading information without the nuisance of compass errors • Gyro stays in a vertical plane • Is subject to errors cause by friction at about 15 degrees per hour © 2015 Coast Flight Training. All Rights Reserved.

Heading Indicator Check • Align to magnetic heading every 15 minutes and at beginning of flight • Should indicate known headings during taxi • Match the magnetic compass during straight and level, unaccelerated flight © 2015 Coast Flight Training. All Rights Reserved.

Electrical Gyroscopic Instruments • One Instruments is powered by Electricity supplied by the Battery: • Turn Coordinator • Still operates on the same principles as vacuum system © 2015 Coast Flight Training. All Rights Reserved.

Turn Coordinator / Slip-Skid Indicator • Instrument relies on controlled precession in order to indicate rate of turn • Mounting of the gyro allows to sense both roll rate and turn rate • Reacts to movement about horizontal plane as aft pressure increases • Powered by an electric motor • Slip and Skid indicator indicates Yaw • Maintain coordinated flight (perpendicular to relative wind) © 2015 Coast Flight Training. All Rights Reserved.

How does the TC Work? • Uses principle of precession • Yaw from turn causes force on side of gyro • Force is translated 90 deg in direction of spin, which rolls the gyro and mini airplane or needle © 2015 Coast Flight Training. All Rights Reserved.

Skidding vs. Slipping • Skidding Turn • Nose is yawed in the direction of the turn • Slipping Turn • Nose is yawed away from the direction of the turn © 2015 Coast Flight Training. All Rights Reserved.

Magnetism • Magnet is a piece of metal containing iron that has a north and south pole which attracts magnetic flux • The earth acts as a giant magnet, so a magnet can be aligned with the earths flux fields • Magnet floats in kerosene fluid and is always trying to stay with magnetic north • Airplane pivots around the compass • Pilot sees headings as etched into the card © 2015 Coast Flight Training. All Rights Reserved.

Compass Errors - Variation • The difference between true and magnetic north • Aeronautical charts referenced to true • Runways aligned with magnetic • Variation needs to be taken into consideration © 2015 Coast Flight Training. All Rights Reserved.

Compass Errors - Deviation • Any error caused by a magnetic field other than the earths • This could be a battery, magneto, alternator, or other electromagnetic disturbance • When a mechanic aligns the aircraft with known magnetic headings, he can denote deviation • Compass Deviation Card © 2015 Coast Flight Training. All Rights Reserved.

Magnetic Dip • Occurs when lines of flux dip into the earth over the poles • Compass has a dip compensating weight • Weight is the cause of northerly turning errors • Also the cause of acceleration errors © 2015 Coast Flight Training. All Rights Reserved.

Acceleration Error • On an East or West Heading • Acceleration indicates a turn to the North • Deceleration (or negative acceleration) indicates a turn to the south • ANDS © 2015 Coast Flight Training. All Rights Reserved.

Oscillation Error • Combination of all the errors results in small movements, or swings in the compass indications • Why we use the heading indicator in IMC © 2015 Coast Flight Training. All Rights Reserved.

Digital Flight Instruments • Newer Aircraft include a PFD and MFD • Primary Flight Display and Multi-Function Display • Both integrate all of the engine parameter and flight instruments into two large, panel mounted screens © 2015 Coast Flight Training. All Rights Reserved.

Required Instruments for Flight – 91. 205 • Changes for day and night • ATOMATOFLAMES Acronym – day • FLAPS - Night • Read and Highlight the Regulation • MEMORIZE! © 2015 Coast Flight Training. All Rights Reserved.

ELT Requirements – 91. 207 • Batteries to be replaced: • 1 hour of cumulative use • 50% of useful life • Does not apply: • Aircraft engaged in training if within 50 miles • Agricultural • Not carrying more than one person © 2015 Coast Flight Training. All Rights Reserved.

Inoperative Instruments – 91. 213 • Does an MEL Exist? • May be without MEL if: • Non-turbine • Not part of ATOMATOFLAMES or FLAPS • Option 1: Remove from the Aircraft, adjust maintenance records • Option 2: Deactivate and placard inoperative • Both options require that PIC make safety determination • Final Option: Special Flight Permit © 2015 Coast Flight Training. All Rights Reserved.