Task H. Navigation & Radar Services

https://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gbng/vormon#:~:text=The%20Very%20High%20Frequency%20Omni,Positioning%20System%20(GPS)%20signal

What do Antennas do?

Converts the electrical current of a signal into a radio wave to travel through space to a receiving antenna which it is then converted back to electrical current to be read by the device

What are the 3 different types of radio waves?

• Ground Waves

• Sky Waves

• Space Waves

What are Ground Waves?

• Lower frequency waves that travel closer to the earth

• Follows earths curvature

• The lower the frequency of the wave, the father it can travel

What are Sky Waves?

• Higher frequency waves that don't follow earth's curvature

• Waves are “refracted/ Bent” by the Ionosphere & sent back down to earth

• Its a way to send messages across the ocean using very little PWR 

  • 50 to 100 watts usually

What are Space Waves?

• Consists of VHF or higher waves that do not refract or bend

• They go right through the ionosphere

• This allows for navigation from space

• Any objects between the transmitter & receiver may block the signal

  • Line need line of sight

What is an NDB?

Non-Directional Beacon (NDB)

• One of the OLDEST Nav Aids

  • Very few still operate in the US

• It is a ground based Am radio that transmits in all directions

  • They operate on frequency range of 190 - 535 KHz (Low to Medium Wave/ Band)

How do we use an NDB to naviagate?

Homing & Tracking

• Homing: This involves flying directly towards the NDB adjusting the heading as needed to keep the needle centered (Maintaining a 0° relative bearing)

  • This method does not account for wind correction, and the aircraft may be blown off course by crosswinds, resulting in a longer and less efficient path to the beacon

• Tracking: This method involves maintaining a constant bearing to the NDB, which may not be the most direct path. Pilots apply wind correction to their heading to maintain a desired track to or from the station. This ensures that the aircraft follows a more precise and efficient path, compensating for any crosswinds that might push the aircraft off course

What equipment do we use with an NDB?

Equipment

• ADF (Automatic Direction Finder)

  • MH (Magnetic Heading) + RB (Relative Bearing) = MB (Magnetic Bearing)

What does an NDB look like on a Sectional Chart & what does its info box contain?

The magenta circle & info box denote an NDB

• Info Box contains

  • NDB name

  • Frequency

  • ID

  • Morse Code Identifier

What are the 4 classes of NDB?

• Compass Locator

  • Just over 25 watts

  • Range of 15 NM

• Medium-High

  • 25 - 50 Watts

  • Range of 25 NM

• High

  • 50 watts - 2 kW

  • Range of 50 NM

• High-High

  • Less than 2 kW

  • Range of 75 NM

What are the 2 antennas used for receiving NDB signals?

• Loop Antenna

• Sense Antenna

What is a Loop Antenna & how does it work?

• Directional antenna with 1 or more loops

  • If radio waves hit the loop (besides perpendicular) a voltage will be induced over the antenna

What is a Sense Antenna & how does it work?

It Is able to use the waves provided by the loop antenna to determine which one is the correct bearing & remove ambiguity of other signals

What are some NDB & ADF errors?

• Thunderstorm effect

  • ADF needle will temporarily deflect towards lighting strikes

• Night effect

  • NDB signals can be refracted by the ionosphere & return as sky waves

    • Most prevalent during dawn & dusk hours

• Mountains

  • They can reflect the NDB signal

• Coastal effect

  • The ADF needle will slightly bend towards the coast line if crossing at an angle

• Hearing any static in the Morse code or ADF needle acting erratically usually means there are errors

What is a VOR?

Very High Frequency Omni-directional Range (VOR)

• Still widely in use and much more common

• They Operate in the frequency band of 108 - 117.95  MHz (Space Waves)

• Requires line of sight

• Oriented to Magnetic North

• Signal is sent out in every direction

What are the 3 main parts to a VOR Indicator?

• Course Deflection Indicator (CDI)

  • How far off center from the course you are in Degrees

• To/ From Indicator

  • If you are flying TO or FROM the set radial

• Omni Bearing Selector (OBS)

  • The OBS knob is used to set the course or radial you'd like to reference

Course VS Radial

• Course: Directed towards the VOR station

  • When flying towards a station

• Radial: Directed away from the VOR station

  • Flying away from a station

Explain how Radials/From & Course/To Indications work & are related?

• The Station does not know what direction or heading the aircraft is flying

  • EXAMPLE: You are south of the VOR flying northbound, you could tune into the 180 Radial w/ FROM indication, or you could tune a 360 course with a TO indication

  • Watchout for reverse sensing 

    • HSI automatically compensate for this

What is the Cone of Confusion?

• Area above the VOR where the airplane does not get a clear or any signal

  • TO/ FROM indicator will swap to “Off position”

What is a DME?

Distance Measuring Equipment (DME)

• This will tell you how far from the VOR you are

  • It gives it in Slant range, not across the ground distance

• Operates in the UHF between 962 - 1213 MHz

• Emits a morse code signal every 30 seconds to indicate it is working

• It has a range of 199 NM but only serves the closest 100 aircraft

• Subject to line of sight rules

How does the DME work?

The aircraft DME sends a signal to the station which then sends the signal back. It measures the time it took for the signals trip to complete then converts it to distance

• The distance given is the “Slant Range Distance”

  • The distance shown is the exact distance to the station NOT the distance across the ground

  • Effect is worse at higher altitudes

How to use 2 different VORs to find your location?

Also Called triangulation

• Pick 2 Nearby VORs and tune them in,

• Center both VORs w/ FROM Flags to get the Radials

• Then use a sectional chart to plot the 2 lines, where they intersect is your location

Do you have to get the VOR checked, & if so how often?

• You must check your VOR every 30 days for IFR Operations ONLY

  • Not required for VFR Operations (But still a great idea)

VOR Check - VOT Signal

It's an approved VOR test signal, and it's located on an airport. here's what to do:

• Tune VOR to VOT signal.

• Set the course selector to 0 degrees

  • Track indicator should be centered

  • The TO-FROM indicator should read FROM.

• Then set the course selector to 180 degrees

  • TO-FROM indicator should read TO

  • Track bar should be centered.

• The maximum indicated bearing error is plus or minus 4 degrees.

Not all airports have this, check supplements

VOR Check - VOR Checkpoint

VOR checkpoint signs are usually located near

• Taxiways

• Ramps

• Runup area

The signs indicate the exact point on the airport where there is sufficient signal strength from a VOR to check the aircraft's VOR receiver against the radial designated on the sign.

• To use a VOR checkpoint, simply follow the instructions on the sign.

The maximum indicated bearing error is plus or minus 4 degrees

VOR Check - Dual VOR Checkpoint

Easiest way to check as long as you have 2 VOR receivers.

To check dual VOR receivers against one another:

• Tune both NAV radios to the same VOR facility.

• Center the needles of each VOR receiver with a "TO" indication.

• Note the indicated bearings to the station from each receiver

The maximum permissible variation between the two indicated bearings is 4 degrees.

VOR Check - Airborne VOR Check

VOR equipment can also be checked for accuracy in flight.

To accomplish an airborne VOR check:

• Select a VOR radial that lies along the centerline of an established VOR airway.

• Select a prominent ground point along the selected radial preferably more than 20 nautical miles from the VOR ground facility and maneuver the aircraft directly over the point at a reasonably low altitude.

• Note the VOR bearing indicated by the receiver when over the ground point.

The maximum indicated bearing error is plus or minus 6 degrees.

What info is required for the VOR check log?

• Date of the check

• Location of the check

• Bearing errors encountered

• Pilots signature in

  • Aircraft logbook or other record

How to know if a VOR is operational?

VORs transmit 3 letter identifiers in Morse Code

• No need to continuously monitor the frequency

• If the station is inoperative, the TO/ FROM flag will show “Off” with no Morse Code signal transmitted

• Some new GPS systems can identify the VOR for you

What is a Service Volume?

It’s a three-dimensional area where aircraft can reliably pick up the NAVAID’s signal, free from interference.

When using a VOR within its service volume, the FAA ensures navigational accuracy, accounting for standard errors.

What are Legacy VOR Service Volumes?

All start @ 1,000ft AGL

• Terminal

  • Usually co-located with airports and are typically used for approaches.

• Low

• High

What are New Service Volumes?

Starts at 1,000' ft AGL

• VOR Low

• VOR High

What does a VOR & info box look like on a sectional chart?

• A compass rose is shown for help plotting Radials/ Courses

• Like NDBs, has a info box with:

• Name

• Frequency

• Morse code identifier

What are Victor Airways?

Predefined Low Altitude Routes pilots can use to navigate along

• Shown on VFR sectionals & Low Altitude IFR enroute charts

• Extend from 1,200’ AGL up to but not including FL180

• 4 NM width each side of the course

  • 8 NM Total

What are the different types of VOR?

• VOR

• VOR DME

• VORTAC

VOR (VHF Omnidirectional Range)

• Radio navigation system that allows pilots to determine their position relative to the VOR station.

• Transmits a 360-degree signal that helps pilots navigate along specific Radials & Courses

VOR-DME (VOR with Distance Measuring Equipment)

• Combines VOR functionality with DME to provide distance info

• Pilots can determine their bearing & how far they are from the VOR station

  • Enhances situational awareness.

  • Useful for precise navigation and approach procedures.

VORTAC (VOR Tactical Air Navigation)

• Integrates both VOR and DME functions with a TACAN system, primarily for military use.

• Provides the same info as VOR-DME but also offers a compatible format for military aircraft.

  • Often used in joint operations, allowing both civilian & military pilots to utilize the same nav aids

What is GPS?

Global Positioning System

• USAs version of a Global Navigation Satellite System (GNSS)

• Testing began in the 1970s and became fully operational in 1995

What are the 3 major elements of the GPS system?

• Space Segment

• Control Segment

• User Segment

What makes up the Space Segment?

• A constellation of 31 satellites about 11,000 NM above earth

  1. The US Maintains 24 operational satellites at least 95% of the time

  2. Arranged so at any time, 5 are in view to any receiver (4 are required for operation minimum)

  3. Each satellite orbits the Earth in approximately 12 hours at speeds of 7,000 MPH

  4. Equipped with highly stable atomic clocks and transmit a unique code/nav message

• The satellites broadcast in the UHF range

  • Nearly unaffected by weather

  • Subjected to line-of-sight references

    • Must be above the horizon (as seen by the antenna) to be usable for navigation

What makes up the Control Segment?

• Consists of a master control station, 5 monitoring stations, and 3 ground antennas

• Help ensure accuracy of:

  • GPS positions & Atomic Clocks

• Master station collects info & is able to send Updates/corrections to the satellites as they pass over the ground antennas

What makes up the User Segment?

• Consists of all components associated with the GPS receiver

  1. Range from portable, hand-held receivers to those permanently installed in the plane

• The receiver utilizes the signals from the satellites to provide:

  • Positioning, velocity, and precise timing to the user

How many satellites does it take to find our position?

• 3 Satellites are needed to find your 2D location

  • latitude & longitude

• 4 Satellites are needed to find your 3D Location

  • Latitude, longitude, altitude, and time solution

• 5 Satellites are in view at any time, sometimes more.

  • If 5 or more help provide efficiency, redundancy, & backup of singal

GPS Navigation VS VOR Navigation?

• For a GPS, you just input your destination and your all set

• No station to tune into or verify

• Course Deviation is linear, so it has the same amount of sensitivity no matter what

• No need to deal with/ figure out TO/ FROM flags

Although GPS is super easy, it is never a good idea to rely on only one form of Navigation when flying

• VOR is great for waypoints

• Stiill in wide use across america

• many IFR approaches still use VOR in some way

What is RAIM?

Random Autonomous Integrity Monitoring

• It verifies the integrity of signal & info sent from the satellites to the aircraft

• 5 - 6 Satellites are needed to calculate RAIM

Talk about RAIM Outages, what happens with them, and how we know if we have RAIM or not?

• RAIM outages happen when

  • There is an insufficient number of GPS satellites

  • There is an unsuitable Satellite geometry

• On our GPS unit, it will display if we have RAIM or not by saying “RAIM not available"‘

Things to think about & know when using GPS for VFR navigation?

GPS installs can vary between full IFR setups or basic handheld receivers

• Some dont even support RAIM

• sometimes aircraft anntena location is far from ideal

• With no RAIM & loss of signal, position errors could be as high as 300 ft off

• Know your setups limitations before full use

Talk about Database Currency & things to remember with it?

• Aircraft map database must be updated & current for IFR operations (AIM 1-1-1b3(b))

  • No requirements for VFR operations

• It is always best practice to used updated databases no matter what operation is being conducted

  • Normal & Special use airspace dimensions may have shifted with any update.

  • Not having up to date data could mean you bust the airspace

What is WAAS and how does it work?

Wide Area Augmentation System

• Designed to highly improve accuracy, integrity, & availability of GPS signals

• As the initial signal is sent it is monitored by Wide Area Reference Stations.

  • They monitor the signal and relay the data to Wide Area Master Stations.

  • The Master stations compute a correction to the GPS signal which is sent to a stationary WAAS satellite via Ground up-link stations.

  • That correction is then sent to the original satellites

What is LAAS & how does it work?

Local Area Augmentation System

• Also refereed to as GBAS

  • Ground Based Augmentation System

• All-weather aircraft landing system based on real-time differential correction of the GPS signal. 

• Local reference receivers located around the airport send data to a central location at the airport

  • Data is used to formulate a correction message, which is then transmitted to users via a VHF Data Link

• Information is used to

  • Correct GPS signals

  • Provide ILS-style display while flying a precision approach

What are ATC Radar Services?

ATC facilities equipped with Radar to provide assistance & navigation to VFR aircraft as long as:

• You can communicate w/ ATC

• Are within Radar coverage

• Can be Radar Identified

Some limitations of Radar services?

• Based on controllers discretion

  • Usually if to busy or other priority events happening

• Guidance info is ADVISORY ONLY

  • Safe flying remains with PIC

• Cannot determine if flight will lead into IMC conditions from instructions given

What are some ATC services a VFR pilot could request?

• Flight Following (Basic radar service)

  • Safety alerts, traffic advisories, limited radar vectoring (workload permitting)

• TRSA Service

  • Radar sequencing and separation for VFR aircraft in a TRSA

• Class C services 

  • Separation between IFR/VFR and sequencing of VFR traffic to the airport

• Class B services

  • Separation based on IFR, VFR and/or weight and sequencing VFR arrivals

What is ADS-B?

• Automatic: Automatically transmits information

• Dependent: Position & Velocity are derived from GPS/FMS

• Surveillance: Allows 3D position and identification 

• Broadcast: Transmits the information to anyone with appropriate receiving equipment

Broadcasts this info every second

What is ADS-B Out?

It broadcasts GPS location, altitude, ground speed, more to ground stations/other aircraft

What is ADS-B in?

• Pilots can see what controllers see in the air and on the ground

  • Can also provide in-flight weather

• FIS-B (Flight Information Service Broadcast – available on 978 MHz UAT equipment)

  • Like XM weather, but more information 

• TIS-B (Traffic Information Service Broadcast – available to 1090ES and UAT equipment users)

  • Provides traffic information on all transponder-based aircraft in the vicinity of the ADS-B

IS ADS-B required?

• FAR 91.225 – Effective Jan 1, 2020, ADS-B OUT is required in:

  • Class A, B, and C airspace (and above the ceiling of Class B and C airspace up to 10,000’ MSL)

  • Class E airspace at & above 10,000’ MSL, excluding at & below 2,500’ AGL

    • At & above 3,000’ MSL over the Gulf of America within 12 nm of the coast

• ADS-B IN is voluntary

How to get a temporary ADS-B Deviation Authorization?

• “ADS-B Deviation Authorization Preflight Tool” (ADAPT) must meet the following:

  • Must be equipped w/ operational:

    • transponder

    • altitude encoder 

  • Submit no more than 24 hours before flight and no less than 1 hour before flight

What is a Transponder?

An automated transceiver that, upon receiving an interrogating signal from a ground-based radar system, responds with a coded signal, helping air traffic control track and identify aircraft

What are the different Modes (Models) of a transponder?

• A: Transmits 4-digit code that identifies an aircraft and its position

• C: Mode A + ATC can see the aircraft’s altitude 

• S: Transmits a variety of information to ATC & other aircraft

  • Unique ICAO address (assigned to each aircraft)

  • Heading, speed, other flight related data

  • Integral to TCAS (Traffic Collision Avoidance System) and ADS-B

When is a transponder required?

A transponder is required only when:

• In Class A, Class B, or Class C airspace.

• Above 10,000 ft MSL, excluding airspace below 2,500 ft AGL

• Within a Class B Mode C Vail

  • 30 NM radius from center of Class B

• Above & inside lateral boundaries of Class B or Class C airspace up to 10,000 feet MSL.

Things to remember when using EFB

• Pilots are responsible for proper use of an EFB and installed avionics

  • Pilots may be evaluated on the use and interpretation of an EFB or installed avionics

• Not required, but always maintain current EFB charts and publications 

• Understand the abilities and limitations of the system(s) of your aircraft

  • Always monitor & ensure system is doing what you intend, when you intend it

  • Ensure the autopilot system is properly programmed to fly off the appropriate nav source

  • A lack of familiarity can be a tremendous distraction in the cockpit & pull focus away from flying/scanning

Distractions to keep in mind and watch for?

Always follow: Aviate, Navigate, Communicate

• Nav systems, GPS, & moving maps can take away pilots attention

• Don’t be overdependent on just one Navigation system, have backup plans

• If you lose Situational Awareness, Admit it, and work to regain it

Good task management procedures?

Divide attention between flying/navigating, scanning, and communicating

• No one responsibility should take your full attention full more than a short period

Recognize when you are getting behind and find a way to catch up