10/5/23 

Pilot/Controller Glossary 

INSTRUMENT APPROACH PROCEDURE [ICAO]

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 A series of predetermined maneuvers by reference to 

flight instruments with specified protection from obstacles from the initial approach fix, or where applicable, 

from the beginning of a defined arrival route to a point from which a landing can be completed and thereafter, 

if a landing is not completed, to a position at which holding or en route obstacle clearance criteria apply. 

(See ICAO term INSTRUMENT APPROACH OPERATIONS) 

INSTRUMENT APPROACH PROCEDURE CHARTS

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(See AERONAUTICAL CHART.) 

INSTRUMENT DEPARTURE PROCEDURE (DP)

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 A preplanned instrument flight rule (IFR) departure 

procedure published for pilot use, in graphic or textual format, that provides obstruction clearance from the 

terminal area to the appropriate en route structure. There are two types of DP, Obstacle Departure Procedure 

(ODP), printed either textually or graphically, and, Standard Instrument Departure (SID), which is always 

printed graphically. 

(See IFR TAKEOFF MINIMUMS AND DEPARTURE PROCEDURES.) 
(See OBSTACLE DEPARTURE PROCEDURES.) 
(See STANDARD INSTRUMENT DEPARTURES.) 
(Refer to AIM.) 

INSTRUMENT DEPARTURE PROCEDURE (DP) CHARTS

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(See AERONAUTICAL CHART.) 

INSTRUMENT FLIGHT RULES (IFR)

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 Rules governing the procedures for conducting instrument flight. 

Also a term used by pilots and controllers to indicate type of flight plan. 

(See INSTRUMENT METEOROLOGICAL CONDITIONS.) 
(See VISUAL FLIGHT RULES.) 
(See VISUAL METEOROLOGICAL CONDITIONS.) 
(See ICAO term INSTRUMENT FLIGHT RULES.) 
(Refer to AIM.) 

INSTRUMENT FLIGHT RULES [ICAO]

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 A set of rules governing the conduct of flight under instrument 

meteorological conditions. 
INSTRUMENT LANDING SYSTEM (ILS)

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 A precision instrument approach system which normally consists 

of the following electronic components and visual aids: 

a. 

Localizer. 

(See LOCALIZER.) 

b. 

Glideslope. 

(See GLIDESLOPE.) 

c. 

Outer Marker. 

(See OUTER MARKER.) 

d. 

Middle Marker. 

(See MIDDLE MARKER.) 

e. 

Approach Lights. 

(See AIRPORT LIGHTING.) 
(Refer to 14 CFR Part 91.) 
(Refer to AIM.) 

INSTRUMENT METEOROLOGICAL CONDITIONS (IMC)

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 Meteorological conditions expressed in terms 

of visibility, distance from cloud, and ceiling less than the minima specified for visual meteorological conditions. 

(See INSTRUMENT FLIGHT RULES.) 
(See VISUAL FLIGHT RULES.) 
(See VISUAL METEOROLOGICAL CONDITIONS.) 

INSTRUMENT RUNWAY

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 A runway equipped with electronic and visual navigation aids for which a precision 

or nonprecision approach procedure having straight-in landing minimums has been approved. 

(See ICAO term INSTRUMENT RUNWAY.) 

PCG I

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