Instrument Rating Groundschool
Session 1
The National Airspace System, Air Traffic Control
(IFH Chapters 1&2)
Requirements for an Instrument
Rating
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Private Pilot or higher certificate
50 hours of cross-country flight time as pilot in command
40 hours of instrument time, 15 hours of which must have been
received from an instrument instructor and a maximum of 20 of
which may be performed in a flight simulator
Instrument flight training including one cross country flight with an
instructor, that is performed under instrument flight rules, when a
flight plan has been filed with an air traffic control facility, and that
involves
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A flight of 250 nautical miles
An instrument approach at each airport
Three different kinds of approaches
Receive a logbook endorsement from an authorized instructor to take
the required knowledge test
Pass the required knowledge test
Pass a practical test
Content
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The National Airspace System, Air Traffic Control
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Human Factors, Aerodynamic Factors, Flight Instruments
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Attitude Instrument Flying, Basic Flight Maneuvers
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Navigation Systems
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IFR Flight
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Departure Procedures
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En Route Operations
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Arrivals
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Approaches
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Improvement Plans, Airborne Navigation Databases
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Emergency Procedures
The National Airspace System
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The national airspace system consists of all airspace, aids to air navigation, air
traffic control facilities, and procedures established to ensure safe and efficient
flow of aircraft from their departure point, through the en route, arrival, and
approach phases of a flight to a destination.
The system is broadly divided into five categories:
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Airspace – Airspace is given various designations to more effectively facilitate
traffic flow and to separate IFR from VFR traffic.
Navigation Aids – Surface or satellite based facilities which guide aircraft
through all phases of a flight and allow for navigation without external visual
reference.
Procedures – Departure, en route, arrival and approach procedures are established
to provide a framework for IFR flights.
Information Services – Flight Service, HIWAS, Center Weather Advisories, ATIS
and other services are established to deliver information necessary to the safety of
flight to pilots.
Charts – Charts and publications for IFR flight disseminate information on
airspace, procedures and navigation to pilots.
Air Traffic Control – Tower, Approach Control, and Air Route Traffic Control
Centers are established to improve traffic flow and provide traffic separation,
routing, and emergency services to pilots
Classification of Airspace
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Airspace is divided into six classes, which have entry and equipment requirements appropriate to their usage. It is
divided broadly into two categories; controlled, and uncontrolled. Controlled airspace is that which requires a
clearance to enter.
The classes of airspace are:
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Class A – Generally, airspace from 18,000 feet mean sea level (MSL) up to and including flight level (FL) 600,
including the airspace overlying the waters within 12 nautical miles (NM) of the coast of the 48 contiguous states and
Alaska. Unless otherwise authorized, all pilots must operate their aircraft under instrument flight rules (IFR).
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Class B – Airspace from the surface to 10,000 feet MSL surrounding the nation’s busiest airports. Clearance is
required for all aircraft to operate in the area, and all aircraft that are so cleared receive separation services within the
airspace.
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Class C – Airspace from the surface to 4,000 feet above the airport elevation surrounding those airports that have a
control tower and approach control. Each aircraft must establish two-way radio communications with the ATC
facility providing air traffic services prior to entering the airspace.
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Class D – Airspace from the surface to 2,500 feet above the airport elevation (charted in MSL) surrounding those
airports that have a control tower. Unless otherwise authorized, each aircraft must establish two-way radio
communications with the ATC facility providing air traffic services prior to entering the airspace.
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Class E – The airspace which is not Class A, B, C, or D, and is controlled airspace. Class E airspace extends upward
from either the surface or a designated altitude to the overlying or adjacent controlled airspace. In this class are
federal airways, airspace beginning at either 700 or 1,200 feet above ground level (AGL) used to transition to and
from the terminal or en route environment, and en route domestic and offshore airspace areas designated below
18,000 feet MSL.
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Class G – Airspace not designated as Class A, B, C, D, or E. Class G airspace is also known as uncontrolled airspace,
and generally extends from the surface to 700, 1200, or 14,500 feet as appropriate.
Federal Airways
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The primary means for routing aircraft operating under IFR is the Federal
Airways System. Each Federal airway is based on a centerline that extends from
one navigational aid (NAVAID) to another NAVAID. A Federal airway includes
the airspace within parallel boundary lines 4 NM to each side of the centerline.
The airspace of a Federal airway has a floor of 1,200 feet AGL, unless otherwise
specified.
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The general types of airway are:
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Victor Airways – From 1,200 feet AGL up to, but not including 18,000 feet MSL,
these airways are designated on sectional and IFR low altitude en route charts
with the letter “V” followed by a number (e.g., “V23”). Typically, Victor airways
are given odd numbers when oriented north/south and even numbers when
oriented east/west.
Jet Routes – exist only in Class A airspace, from 18,000 feet MSL to FL 450, and
are depicted on high-altitude en route charts. The letter “J” precedes a number to
label the airway.
Area navigation (RNAV) routes have been established in both the low-altitude
and the high-altitude structures in recent years and are depicted on the en route
low and high chart series. High altitude RNAV routes are identified with a “Q”
prefix (except the Q-routes in the Gulf of Mexico) and low altitude RNAV routes
are identified with a “T” prefix. RNAV routes and data are depicted in
aeronautical blue.
IFR Charts
Communications Equipment
• Radio is critical to IFR Flight. It provides both
communication and navigation, sometimes with
functions combined.
• Most radio in civil aircraft uses the VHF band in a range
from 108.00MHz to 136.975MHz at 25kHz spacing, with
108.00 to 117.95 being devoted to NAVAIDs, and 118.00
to 136.975 being reserved for communication. Nondirectional Beacons (NDBs) use amplitude modulation in
a range of 190kHz to 1750kHz.
• Sometimes it is necessary to Listen on a NAVAID
frequency, and Transmit on a separate communication
frequency in order to communicate with a ground facility.
Communication Facilities
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Facilities used to communicate with aircraft take many forms:
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Flight Service Stations (FSS) – A pilot’ s first contact with A TC is usually through FSS,
555 either by radio or telephone. FSSs provide pilot briefings, receive and process flight
plans, relay ATC clearances, originate Notices to Airmen (NOTAMs), and broadcast Po
aviation weather. Some facilities provide En Route Flight Advisory Service (EFAS),
take weather observations, and advise United States Customs and Immigration of
international flights.Telephone contact with Flight Service can be obtained by dialing 1800-WX-BRIEF. Flight plans filed with Flight Service are sent to the host computer at
the ARTCC (Center). After processing the flight plan, the computer sends flight strips to
the tower, to the radar facility that handles the departure route, and to the Center
controller whose sector the flight first enters.
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ATC Towers – Where there is a dedicated clearance delivery position, that frequency is
found in the A/FD and on the instrument approach chart for the departure airport. Where
there is no clearance delivery position, the ground controller performs this function. At
the busiest airports, pre- taxi clearance is required; the frequency for pre-taxi clearance
can be found in the A/FD. Taxi clearance should be requested not more than 10 minutes
before proposed taxi time. It is recommended that pilots read their IFR clearance back
to the clearance delivery controller. Instrument clearances follow a format that allows a
pilot to be prepared. The format is: clearance limit (usually the destination airport);
route, including any departure procedure; initial altitude; frequency(for departure
control); and transponder code. With the exception of the transponder code, a pilot
knows most of these items before engine start. One technique for clearance copying is
writing C-R-A-F-T.
Communication Facilities
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Terminal Radar Approach Control (TRACON) – TRACONs are
considered terminal facilities because they provide the link between
the departure airport and the en route structure of the NAS. Terminal
airspace normally extends 30 nautical miles (NM) from the facility
with a vertical extent of 10,000 feet; however, dimensions vary widely.
Class B and Class C airspace dimensions are provided on aeronautical
charts. At terminal radar facilities, the airspace is divided into sectors,
each with one or more controllers, and each sector is assigned a
discrete radio frequency. All terminal facilities are approach controls
and should be addressed as “Approach” except when directed to do
otherwise (e.g., “Contact departure on 120.4.”).
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Air Route Traffic Control Center (ARTCC) – ARTCC facilities are
responsible for maintaining separation between IFR flights in the en
route structure. Center radars (Air Route Surveillance Radar (ARSR))
acquire and track transponder returns using the same basic technology
as terminal radar.