Instrument Study Flashcards
How often must the altimeter system be tested and inspected?
Every 24 calendar months
What two fundamental concepts apply to gyroscopes?
- Rigidity in space
- Precession
Explain “rigidity in space” as it pertains to gyroscopes
This is the concept that a spinning wheel resists movement when mounted to gimbals, allowing the gimbals’ base to tilt, twist or otherwise move around the gyro.
Explain precession as it pertains to gyros.
When an outside for tries to tilt a spinning gyro, the gyro responds as if the force had been applied at a point 90deg further/later around in the direction of rotation.
How does precession affect certain flight instruments?
Unwanted precession is caused by friction in the gimbals and bearings of the instruments, causing a slow drifting in the heading indicator and occasional small errors in the attitude indicator
What errors do you find on attitude indicators?
- During coordinated turns, the gyro precesses toward the inside of the turn.
- When rolling out of a steep 180deg turn, the aircraft on the AI will show a slight climb and turn in the opposite direction. (This action is cancelled out after a 360deg turn)
- AI may indicate climb during acceleration and indicate a descent during deceleration
- When rolling out of a 180deg skidding turn, the AI shows a turn in the direction opposite of the skid
Standard Rate Turn Formula
Angle of Bank = (KTAS/10) + 5
i.e.
AoB = (60/10) + 5
9 = 6 + 5
Slipping Turn
Because of insufficient rudder pressure, the aircraft does not turn fast enough for it’s bank angle. The horizontal component of lift exceeds the centrifugal force which opposes the turn. As a result the inclinometer falls to the inside of the turn. (Think of a forward slip).
Skidding Turn
Excessive rudder pressure forces the aircraft to turn faster than normal for the bank angle. The horizontal component of lift is insufficient to overcome the centrifugal force. The inclinometer swings to the outside of the turn. (Think of cars drifting)
Magnetic Variation
The angular difference between true north and magnetic north.
Magnetic Deviation
Error due to magnetic interference with metal components in the aircraft.
Magnetic Dip
Tendency for magnetic compass to tilt downward. Most prominent at north pole.
Magnetic Compass Acceleration Error
ANDS
Magnetic Compass Turning Error
UNOS
CAS
Calibrated Air Speed
IAS corrected for installation and instrument errors.
EAS
Equivalent Airspeed
CAS corrected for adiabatic compressible flow at a particular altitude
TAS
True Airspeed
Actual speed aircraft moves through undisturbed air.
As density altitude increases, TAS increases for a given CAS or for a given amount of power. As the air becomes less dense (aka less effective/less drag) TAS increases
Types of altitude
- Indicated
- Calibrated
- Pressure
- Density
- True
- Absolute
Indicated Altitude
Altitude read from altimeter
Calibrated Altitude
Indicated altitude, corrected for instrument error
Pressure Altitude
Is displayed when altimeter set to 29.92”Hg. Vertical distance above Standard Datum Plane
SDP
Standard Datum Plane
Theoretical plane where atmospheric pressure = 29.92”Hg
Density Altitude
Pressure altitude corrected for nonstandard temperature
True Altitude
Actual height above MSL.
Absolute Altitude
The actual height above earths surface
The VSI Displays _____.
- Rate Information
- Trend Information
Pitot Tube Blockage Error
If ram inlet ONLY is blocked:
- Airspeed will drop to 0 as pressure in line vents through drain hole.
If ram and drain hole blocked:
- ASI will react as altimeter if static port remains clear.
Static Port Blockage Affects on ASI
ASI - will react, but will not be correct. When above the altitude where it became blocked, ASI will read lower than it should. When below the altitude where it became blocked, ASI will read higher than it should. The greater the distance the greater the error.
Static Port Blockage Affect on Altimeter and VSI
Both will freeze
Fundamental Skills of Instrument Flying
- Cross-Check
- Interpretation
- Aircraft Control
Two Methods for Attitude Instrument Flying
- Control and Performance
- Primary/Support Concept
Control and Performance Concept
Accurately establish a specific attitude and power setting using the control instruments. Performance instruments provide feedback to confirm and support the control instruments
Primary/Support Concept
Divides panel into pitch, bank, power instruments. For a given maneuver, instruments providing the most essential information are primary while instruments helping maintain primary are supporting instruments.
CDI
Course Deviation Indicator
HSI
Horizontal Situation Indicator
OBS
Omni Bearing Selector
VOR Time and Distance Calculation
Distance = (Time to Station (Mins) X TAS)/Degrees of Bearing Change
i.e.
D = (6mins X 60ktas) / 10deg
D = 360/10 = 36nm
VOR Isosceles Triangle Time Calculation
- Turn 10deg off course
- Turn Course Selector 10deg in OPPOSITE direction
- Time to station is same as time it takes for your CDI to center (assuming no wind)
i.e. Tracking: 90deg TO VOR Set CDI to: 80deg Turn to: 110deg Start time and wait for CDI to center.
SSV
Standard Service Volume (Radius and height) of a VOR
TVOR
Terminal VOR - Short range facility used in terminal areas for instrument approaches
TVOR SSV
25NM Radius @ 1000’ to 12,000’
LVOR
Low VOR used for nav on most airways, and can also function as approach facilities when on or near an airport
LVOR SSV
40nm Radius @ 1,000’ to 18,000’
HVOR
High VOR - Used for nav on most airways, and can also function as approach facilities when on or near an airport.
HVOR SSV
1,000’ to 14,500’: 40nm Radius
14,500’ to 18,000’: 100nm Radius
18,000’ to 45,000’: 130nm Radius
45,000’ to 60,000’: 100nm Radius
Types of VOR Checks
- VOT
- VOR Checkpoints (ground and airborne
- Dual VOR
VOT
VOR Test Facility
- Transmits on 360deg
- +/-4 degrees
- If using RMI, bearing pointer should be 180deg +/-4
VOR Ground Checkpoint
- Taxi to specific point on the airport that is designated in the VOR Receiver Check section of the A/FD.
- Center CDI
- Compare VOR course to published radial for that checkpoint (A/FD)
- +/-4 degress
VOR Airborne Checkpoint
Listed in A/FD
- Usually located over easily identifiable terrain or prominent ground features.
Can also be performed on centerline of an airway.
- Locate prominent terrain feature under centerline of airway, preferable 20nm or more from VOR station.
- Center CDI when over point and note what course is selected.
- +/- 6 degrees permissible
Dual VOR Check
Set two separate VORs to same facility and note indications of each.
+/-4 degrees permissible
DME accuracy
- Accurate within 1/2 mile or 3%, whichever is greater.
- DME considered accurate when you are at least 1nm from the station for every 1,000’ above the site elevation.
DME Arc
- Used for transitioning from enroute to approach course
- About 1/2 mile from reaching the arc, turn 90 degrees from current course
- Fly a heading so RMI is 5 to 10 degrees ahead
of wingtip - Continue flying that heading until RMI is 5 to 10 degrees behind wing tip.
- Turn inside the arc so that RMI is once again 5 to 10 degrees ahead of wingtip.
- Continue process until meeting Approach Course
- If using conventional VOR, set OBS to a radial 20degrees ahead of present position.
- Then turn and maintain a heading 100degrees from the radial you just crossed.
- Once CDI centers, or you reach the arc, repeat the process to fly another segment.
What does Area Navigation (RNAV) compute
- Aircraft position
- Actual track
- ground speed
- distance and time estimates relative to selected course or waypoint.
What Navigational Systems are included in RNAV
- VOR/DME RNAV
- Intertial Navigation Systems (INS)
- Global Positioning Systems (GPS)
RNP
Required Navigation Performance
- Set of standards that apply to both airspace and navigation equipment
- Aircraft must stay within a specified distance of the centerline of a route, path, or procedure at least 95% of the time
- Within 2nm for enroute ops
- Within 1nm for terminal operations
- Within 0.3nm for approach operations
VOR/DME RNAV
A Pre-GPS RNAV system that uses an airborne course-line computer (CLC) to create waypoints based on navigation data from VORTAC or VOR/DME facilities.
- These systems create “phantom VORs” at specified radials & distances from actual VORs, enabling more direct navigation.
- Required manual programming of waypoints to fly approaches (now prohibited)
- Being phased out
INS
Intertial Navigation System
- A self-contained system that uses gyros, accelerometers, and a nav computer to calculate position.
- By programming a series of waypoints, the system will navigate along a predetermined track
- Extremely accurate when set to known position upon departure
- Accuracy degrades 1 to 2nm per hour.
- Automatically update position by incorporating inputs from VOR, DME, &/or GPS.
FMS
Flight Management System
- Automates tasks of managing onboard navigation equipment.
- Acts as input/output device for nav data from navaids
- Calculates position, track, desired heading, and groundspeed.
GPS
Global Positioning System
- Satellite-based radio navigation system
- Broadcasts a signal used by receivers to determine precise location, calculate time, distance, and bearings to waypoints, computer groundspeed, and provide course guidance
WAAS
Wide Area Augmentation System
- Enhances GPS accuracy
- Series of ground stations that generate a corrective message that is transmitted to the aircraft via geostationary satellite.
- Accounts for positional drift of satellites and signal delays caused by ionosphere and other atmospheric factors.
- WAAS-certified GPS equipment also provides vertical glide path for GPS instrument approaches.
GBAS
Ground-Based Augmentation System (still in development)
- Provides GPS position correction even more precise than WAAS
- Local Receivers send corrections to airport ground facility that transmits corrections to aircraft.
- More localized than WASS (20-30 miles around an airport).
- Should be able to pinpoint aircraft within 3’
GPS Equipment without WAAS approved for IFR is certified by
TSO-C-129
GPS equipment with WAAS certified by
TSO-C145
or
TSO-C146
How can you determine if your GPS is certified for IFR enroute and approach ops, and if it is WAAS certified?
Refer to the Airplane Flight Manual (AFM) or AFM supplements.
Explain the privileges and limitations on TSO-C129 certified GPS equipment
- Can be sole navigation equipment for short oceanic routes.
- Can replace ONE of the required dual INS systems for longer transoceanic routes
- Considered only as supplemental navigation for domestic enroute and terminal IFR flights
RAIM
Receiver Autonomous Integrity Monitoring
- The GPS equipment monitors and compares signals from multiple satellites to ensure an accurate signal.
- GPS requires FOUR satellites to provide a 3D solution (latitude, longitude, and altitude)
- RAIM requires a 5th satellite to monitor the positions provided by the other 4 and alert you to any discrepancy.
- RAIM must be confirmed for the intended route and the duration of the flight using GPS
- If RAIM is predicted unavailable, must you other nav equipment, delay, or cancel the flight.
- Can verify RAIM by checking NOTAMs, contacting Flight Service, referring the FAA RAIM prediction website, or by using the GPS’s onboard RAIM prediction function.
How can you verify RAIM availability?
- NOTAMs
- Flight Service
- FAA RAIM prediction website
- GPS onboard RAIM prediction function
What is required to use GPS for IFR flights?
- RAIM
- Unless you verify WAAS coverage along entire route
- Current Navigation Database
- WAAS requirements
- TSO-C129, TSO-C145 or TSO-C146
- WAAS must be available over 99% of flight, before using GPS as sole navigation equipment
What are the requirements/ limitations of WAAS?
- Must be available over 99% of time
How do you check WAAS coverage?
- NOTAMs
- ATC/ATIS recordings
Random RNAV Routes
- Do not correspond with published courses
- Can only be authorized in a radar environment
- Approval depends on ATC’s ability to provide radar monitoring and compatibility with traffic volume and flow.
When planning flight via GPS you should
comply with the guidelines for using RNAV for IFR flight planning outline in AIM
Where can you find guidelines for using RNAV for IFR flight planning?
AIM
ADF
Automatic Direction Finder
NDB
Non-Directional Beacon
RMI
Radio Magnetic Indicator
Combines slaved compass card and bearing pointer in one instrument
Visual Runway Markings
- Runway Number
- Centerline
- Threshold Markings (if intended for international commerce)
- Aiming Points (if 4,000’ or longer, used by jet aircraft)
Non-Precision Instrument Runway
- Is used with instrument approach that does not have an electronic glide slope.
- Has visual markings plus threshold and aiming points
Precision Instrument Runways
- Are served by nonvisual precision approach aids, such as Instrument Landing System (ILS).
- All Non-Precision Markings
- Touchdown Zone markings are coded to provide distance information in 500’ increments
- Aiming Points are 1000’ from landing threshold
Hold lines are usually between
125’ and 250’ from the runway centerline
Standard Hold Line looks like:
Two solid yellow lines infront of two dashed yellow lines.
- The solid indicate the side that you need to stop on to be clear of the adjoining runway or intersection.
- The dashed lines mean to go through and stop on other side.
ILS Hold Line looks like:
Two horizontal lines with pairs of short vertical lines in between. Yellow
Displaced Threshold looks like:
Solid white line running across runway with chevrons behind it. Can have white arrows behind as well that lead up to the threshold.
Blast Pad/Stopway looks like
Yellow chevrons. Sometimes in conjunction with a yellow Demarcation Bar running horizontally to break it up from the displaced threshold
ALS
Approach Lighting System
Helps pilot transition from instrument to visual
SFL
Sequenced Flashing Lights
RAIL
Runway Alignment Indicator Lights
REIL
Runway End Identifier Lights
VASI
Visual Approach Slope Indicator
- Set to 3deg slope
- Assures safe obstruction clearance within +/- 10deg of centerline, out to 4nm from threshold.
PVASI
projects a two-color visual approach path into the final approach area.
- Pulsating red = below glide path
- Steady red = slightly below glide path
- steady white = on glide path
- pulsating white = above glide path
- Useful up to 4 miles during day, 10 miles at night.
PAPI
Precision Approach Path Indicator
- Single row of two or four lights
- 5 miles during day, 20 miles at night
Tri-Color VASI
Color shift as you are high or low
- must be careful with amber (high) because sometimes area between green and red appears orange/amber as well
Runway Edge Lights
Are used to outline the runway. Are white, except on insturment runways where they're amber for the last 2000'. - HIRL - MIRL - LIRL -
Threshold Lights
Line across runway
- Bidirectional
- Green from approach side
- Red from departure side.
Displaced Threshold Lights
- Green during approach.
- Do not land short of these lights
You may use the are short of the displaced threshold for taxi, takeoff, or rollout purposes when runway edge lights appear in one of the following combinations
- Runway edge lights appear red until the threshold. After threshold, runway edge lights are white.
- If the area short of the displaced threshold is permissible for landing rollout in the opposite direction, threshold lights will not be visible from that direction. Instead opposite direction traffic sees red threshold lights at the end of the runway that is usable for them. Edge lights leading up to the end are yellow for last 2,000’
TDZL
Touchdown Zone Lighting
- Series of white lights, flush-mounted in runway
- Begin approximately 100’ from landing threshold and extend 3,000’ down runway or to midpoint of runway, whichever is less.
- Only visible from approach end of runway.
RCLS
Runway Centerline Lights
- Begin 75’ from landing threshold and extend to within 75’ of opposite end.
- 50’ intervals
- Alternate red and white starting 3,000’ from end of runway
- All red for last 1,000’ of runway
LAHSO Lights
Land and Hold Short Lights
- A row of 5 flush-mounted flashing white lights across hold-short point.
- Are continuously on if land and hold short operations are conducted continuously. So pilots departing and cleared for full runway use can ignore.
Taxiway Lead-Off Lights
Define the curved path of an aircraft from a point near runway centerline to the center of the intersecting taxiway.
- alternate green and yellow
- Spaced 50’
Taxiway Centerline Lights
Green
Taxiway Edge Lights
Blue
PCL
Pilot Controlled Lighting
- Designed to primarily conserve energy
- Key microphone a specific number of times
- 7 times in 5 seconds - max intensity
- Typically turn off after 15 mins
When do airport beacons activate?
- Night Ops
- Ground visibility of < 3sm
- Ceiling is < 1,000’
Class A VFR Minimums
Not Permitted
Class B VFR Minimums
- 3sm
- Clear of Clouds
Class C VFR Minimums
- 3sm
- 1,000’ above
- 500’ below
- 2,000’ laterally
Class D VFR Minimums
- 3sm
- 1,000’ above
- 500’ below
- 2,000’ laterally
Class E VFR Minimums
Below 10,000’MSL
- 3sm
- 1,000’ above
- 500’ below
- 2,000’ laterally
10,000’ MSL and Above
- 5sm
- 1,000’ above
- 1,000’ below
- 1sm laterally
Class E VFR Minimums Below 10,000’ MSL
- 3sm
- 1,000’ above
- 500’ below
- 2,000’ laterally
Class E VFR Minimums at and Above 10,000’ MSL
- 5sm
- 1,000’ above
- 1,000’ below
- 1sm laterally
Requirements for entering Class B Airspace
- Mode C Transponder inside and within 30nm of B airports
- Must be cleared to enter
When must you have a Mode C Transponder?
- In Class A, B, C Airspace
- Within 30nm of Class B Airports
- Above Class C Airspace
- At and above 10,000’ MSL, except at and below 2,500’ AGL.
Where are basic weather minimums for controlled airspace found?
FAR 91.155
Class G VFR Minimums
- 1sm(day), 3sm(night)
- 1,000’ Above
- 500’ Below
- 2,000’ Laterally
Class A Airspace
- 18,000’ MSL to FL600
- Must use High Altitude Enroute Charts
- Use 29.92”Hg for altimeter setting
- Altitudes given in Flight Levels
- Must be rated for instrument flight
- Must be under IFR plan
- Must have IFR equipment: Mode C transponder, radios for direct ATC communication, navigation equipment for appropriate ground facilities.
- When VOR equipment is required for navigation, aircraft must also have DME or suitable RNAV sytem if flight is at or above 24,000’ MSL.
- If DME fails, you must notify ATC immediately.
Class B Airspace
- Surface to 10,000’ MSL
- Pilot participation is mandatory
- ATC clearance must be received before entering.
- Some B have VFR corridors to allow VFR aircraft to easily pass through without contacting ATC.
- Must have 2-way radio
- Must have Mode C transponder inside and within 30nm radius
- Must have VOR receiver or suitable RNAV to fly IFR
Class C Airspace
- Typically consist of 2 circular areas which extend outward from the primary airport and are the 5nm radius core, and the 10nm radius shelf. An additional 10nm out from the shelf is a 20nm radius outer area where participation is not mandatory, but is strongly encouraged.
- Must establish 2 way communication w/ ATC
- Must establish as soon as practicable if departing satellite airport within the C airspace.
- Must have Mode C transponder within and above, class C up to 10,000’ MSL.
- Operating UNDERNEATH shelf does NOT require transponder.
Class D Airspace
- Designated at airports with operational control towers which are not associated with B or C airspace.
- Must establish 2 way radio communication w/ control tower.
- Ceiling is typically 2,500’AGL, but is reported in MSL.
- Ceiling may be raised or lowered as deemed appropriate.
- Depicted as dashed, blue line on sectionals
- Typically 4nm radius, but shape is predominantly dependent on instrument procedure requirements for any particular airport.
Class E Airspace
- Unless otherwise designated, begins at 14,500’ MSL and extends up to, but not including 18,000’MSL.
- Exceptions are Alaska Peninsula west of 160deg longitude, and airspace within 1,500’AGL
- Covers 48 contiguous states, DC, Alaska, 12nm out from coastlines.
- Must operate Mode C transponder at or above 10,000’MSL, excluding at or below 2,500’AGL
- Also includes federal/ Victor airways.
- Airways are 8nm wide (4nm on either side of NavAid radial.
- Airways begin at 1,200’ AGL
- If an airport in Class E or G has a control tower, you must contact the tower within 4nm.
Victor Airways
- Class E Airspace
- Begin at 1,200’ AGL up to 18,000’MSL
- 8nm wide, centered on NavAid radial
Class E Transitional Airspace
- Established between airways and airports to allow IFR traffic to remain in controlled airspace
- Typically begin at 1,200’AGL if associated with an airway.
- Are only outlined on sectional if they border uncontrolled airspace.
- At non-towered airports with approved approaches, Class E transitions typically drop to 700’ AGL.
SVFR
Special VFR
- Flight visibility at least 1sm
- Must be able to remain clear of clouds
- At least 1sm ground visibility for takeoff & landing.
- Not permitted between sunset and sunrise w/out current IFR rating and aircraft.
- SVFR not issued to fixed-wing at nation’s busies airports listed in section 3 of Appendix D of Far 91
Class G Airspace
The area not designated as A, B, C, D, or E and is essentially uncontrolled.
- G terminates at base of Class E at 700’AGL or 1,200’AGL, or at 14,500MSL, except where 14,500’MSL is lower than 1,500’AGL.
- When 1,500’AGL is higher than 14,500’MSL, Class G goes up to 1,500’AGL
Class G VFR Minimums
1,200’AGL or less:
- 1sm & clear of clouds (day)
- 3sm (night)
- 1,000’ above (night)
- 500’ below (night)
- 2,000’ laterally (night)
Over 1,200’AGL, but below 10,000’MSL:
- 1sm (day), 3sm (night)
- 1,000’ above
- 500’ below
- 2,000’ laterally
Over 1,200’AGL, and at or above 10,000’MSL:
- 5sm
- 1,000’ above
- 1,000’ below
- 1sm laterally
Class G VFR Minimums over 1,200’AGL, and at or above 10,000’ MSL
- 5sm
- 1,000’ above
- 1,000’ below
- 1sm laterally
Class G VFR minimums above 1,200’AGL, but below 10,000’MSL
- 1sm (day), 3sm (night)
- 1,000’ above
- 500’ below
- 2,000’ laterally
Class G VFR minimums 1,200’AGL or less
Day - 1sm & clear of clouds Night - 3sm - 1,000' above - 500' below - 2,000' laterally
Airspeed Limitations
- <250kias when below 10,000’MSL
- <200kias when at or below 2,500’AGL and within 4nm of primary Class C or D airport.
- <200kias below Class B shelves
- <200kias in Class B VFR corridors
Types of NOTAMS
- NOTAM(D): Distant Notams
- (FDC) NOTAMs: Flight Data Center Notams
NOTAM(D) content
Information pertaining to navigational facilities.
(FDC) NOTAM Content
- Flight restrictions
- Changes to information on approach procedures & aeronautical charts, prior to normal publication.
Who issues FDC NOTAMs?
National Flight Data Center
NTAP
Notices to Airment Publication
- Issued every 28 days
- contains all NOTAM(D)s and FDC NOTAMS, except for FDC NOTAMS associated with TFRs
What document contains requirements for flying outside the United States?
International Flight Information Manual
International Flight Information Manual
Contains requirements for flying outside of the United States.
ARTCC
Air Route Traffic Control Centers
- Central authority for issuing IFR clearances
- Provides nationwide monitoring of every IFR flight, primarily during enroute phase.
Basic Radar Services
- Safety Alerts
- Traffic Advisories
- Limited Vectoring
- Sequencing at certain locations
TRSA Service
- Radar Vectoring
- Sequencing
- Separation for IFR and participating VFR aircraft
FSS
Flight Service Stations
IFR Climb Considerations
- ATC expects a climb of 500fpm or greater
- If unable, notify ATC of your reduced rate
- “At Pilot’s Discretion” = expected to climb at an optimum rate consistent w/ aircraft performance to within 1,000’ of assigned altitude.
- Then attempt to climb between 500fpm and 1,500fpm for the last 1,000’ of the climb.
When must you fly the centerline of an airway
- During climb
- During cruise
- During descent
- You are nor prohibited from maneuvering to pass well clear of other aircraft in VFR conditions.
- While climbing in VFR conditions, you make gentle S turns to scan area around you.
When are you responsible for collision avoidance on an IFR flight plan?
In VFR conditions.
