IAF -- I SAY AGAIN
IAF- (See INITIAL APPROACH FIX.)
IAP- (See INSTRUMENT APPROACH PROCEDURE.)
IAWP- Initial Approach Waypoint
ICAO- (See INTERNATIONAL CIVIL AVIATION ORGANIZATION.)
ICAO [ICAO]- (See ICAO Term INTERNATIONAL CIVIL AVIATION ORGANIZATION.)
ICING- The accumulation of airframe ice.
Types of icing are:
a. Rime Ice- Rough, milky, opaque ice formed by the instantaneous
freezing of small supercooled water droplets.
b. Clear Ice- A glossy, clear, or translucent ice formed by the
relatively slow freezing or large supercooled water droplets.
c. Mixed- A mixture of clear ice and rime ice.
Intensity of
icing:
a. Trace- Ice becomes perceptible. Rate of accumulation is slightly
greater than the rate of sublimation. It is not hazardous even though
deicing\anti-icing equipment is not utilized unless encountered for an
extended period of time (over 1 hour).
b. Light- The rate of accumulation may create a problem if flight
is prolonged in this environment (over 1 hour). Occasional use of
deicing\anti-icing equipment removes\prevents accumulation. It does not
present a problem if the deicing\anti-icing equipment is used.
c. Moderate- The rate of accumulation is such that even short
encounters become potentially hazardous and use of deicing\anti-icing
equipment or flight diversion is necessary.
d. Severe- The rate of accumulation is such that deicing\anti-icing
equipment fails to reduce or control the hazard. Immediate flight diversion is
necessary.
IDENT- A request for a pilot to activate the
aircraft transponder identification feature. This will help the controller to
confirm an aircraft identity or to identify an aircraft.
IDENT FEATURE- The special feature in the Air
Traffic Control Radar Beacon System (ATCRBS) equipment. It is used to
immediately distinguish one displayed beacon target from other beacon targets.
IF- (See INTERMEDIATE FIX.)
IFIM- (See INTERNATIONAL FLIGHT INFORMATION MANUAL.)
IF NO TRANSMISSION RECEIVED FOR (TIME)- Used by ATC in radar
approaches to prefix procedures which should be followed by the pilot in event
of lost communications.
(See LOST COMMUNICATIONS.)
IFR- (See INSTRUMENT FLIGHT RULES.)
IFR AIRCRAFT- An aircraft conducting flight in accordance with instrument
flight rules.
IFR CONDITIONS- Weather conditions below the minimum for flight under visual
flight rules.
(See INSTRUMENT METEOROLOGICAL CONDITIONS.)
IFR DEPARTURE
PROCEDURE- (See IFR TAKEOFF MINIMUMS AND DEPARTURE PROCEDURES.)
IFR FLIGHT- (See IFR AIRCRAFT.)
IFR LANDING MINIMUMS- (See LANDING MINIMUMS.)
IFR MILITARY TRAINING ROUTES (IR)- Routes used by the Department of Defense
and associated Reserve and Air Guard units for the purpose of conducting
low-altitude navigation and tactical training in both IFR and VFR weather
conditions below 10,000 feet MSL at airspeeds in excess of 250 knots IAS.
IFR TAKEOFF MINIMUMS AND DEPARTURE PROCEDURES- Federal Aviation Regulations,
Part 91, prescribes standard takeoff rules for certain civil users. At some
airports, obstructions or other factors require the establishment of nonstandard
takeoff minimums, departure procedures, or both to assist pilots in avoiding
obstacles during climb to the minimum en route altitude. Those airports are
listed in NOS/DOD Instrument Approach Charts (IAP's) under a section entitled
"IFR Takeoff Minimums and Departure Procedures." The NOS/DOD IAP chart legend
illustrates the symbol used to alert the pilot to nonstandard takeoff minimums
and departure procedures. When departing IFR from such airports or from any
airports where there are no departure procedures, DP's, or ATC facilities
available, pilots should advise ATC of any departure limitations. Controllers
may query a pilot to determine acceptable departure directions, turns, or
headings after takeoff. Pilots should be familiar with the departure procedures
and must assure that their aircraft can meet or exceed any specified climb
gradients.
IF/IAWP- Intermediate Fix/Initial Approach Waypoint. The waypoint where the
final approach course of a T approach meets the crossbar of the T. When
designated (in conjunction with a TAA) this waypoint will be used as an IAWP
when approaching the airport from certain directions, and as an IFWP when
beginning the approach from another IAWP.
IFWP- Intermediate Fix Waypoint
ILS- (See INSTRUMENT LANDING SYSTEM.)
ILS CATEGORIES- 1. ILS Category I. An ILS approach procedure which provides
for approach to a height above touchdown of not less than 200 feet and with
runway visual range of not less than 1,800 feet.- 2. ILS Category II. An ILS
approach procedure which provides for approach to a height above touchdown of
not less than 100 feet and with runway visual range of not less than 1,200
feet.- 3. ILS Category III:
a. IIIA.-An ILS approach procedure which provides for approach
without a decision height minimum and with runway visual range of not less
than 700 feet.
b. IIIB.-An ILS approach procedure which provides for approach
without a decision height minimum and with runway visual range of not less
than 150 feet.
c. IIIC.-An ILS approach procedure which provides for approach
without a decision height minimum and without runway visual range
minimum.
ILS PRM APPROACH- An instrument landing system (ILS) approach
conducted to parallel runways whose extended centerlines are separated by less
than 4,300 feet and the parallel runways have a Precision Runway Monitoring
(PRM) system that permits simultaneous independent ILS approaches.
IM- (See INNER MARKER.)
IMC- (See INSTRUMENT METEOROLOGICAL CONDITIONS.)
IMMEDIATELY- Used by ATC when such action compliance is
required to avoid an imminent situation.
INCERFA Uncertainty Phase) [ICAO]- A situation wherein uncertainty exists as
to the safety of an aircraft and its occupants.
INCREASE SPEED TO (SPEED)- (See SPEED ADJUSTMENT.)
INERTIAL NAVIGATION SYSTEM- An RNAV system which is a form of self-contained
navigation.
(See Area Navigation/RNAV.)
INFLIGHT REFUELING- (See AERIAL
REFUELING.)
INFLIGHT WEATHER ADVISORY- (See WEATHER ADVISORY.)
INFORMATION REQUEST- A request originated by an FSS for information
concerning an overdue VFR aircraft.
INITIAL APPROACH FIX- The fixes depicted on instrument approach procedure
charts that identify the beginning of the initial approach segment(s).
(See SEGMENTS OF AN INSTRUMENT APPROACH PROCEDURE.)
INITIAL
APPROACH SEGMENT- (See SEGMENTS OF AN INSTRUMENT APPROACH PROCEDURE.)
INITIAL APPROACH SEGMENT [ICAO]- That segment of an instrument approach
procedure between the initial approach fix and the intermediate approach fix or,
where applicable, the final approach fix or point.
INLAND NAVIGATION FACILITY- A navigation aid on a North American Route at
which the common route and/or the noncommon route begins or ends.
INNER MARKER- A marker beacon used with an ILS (CAT II) precision approach
located between the middle marker and the end of the ILS runway, transmitting a
radiation pattern keyed at six dots per second and indicating to the pilot, both
aurally and visually, that he is at the designated decision height (DH),
normally 100 feet above the touchdown zone elevation, on the ILS CAT II
approach. It also marks progress during a CAT III approach.
(See INSTRUMENT LANDING SYSTEM.)
INNER MARKER BEACON- (See INNER MARKER.)
INREQ- (See INFORMATION REQUEST.)
INS- (See INERTIAL NAVIGATION SYSTEM.)
INSTRUMENT APPROACH- (See INSTRUMENT APPROACH PROCEDURE.)
INSTRUMENT APPROACH PROCEDURE- A series of predetermined maneuvers for the
orderly transfer of an aircraft under instrument flight conditions from the
beginning of the initial approach to a landing or to a point from which a
landing may be made visually. It is prescribed and approved for a specific
airport by competent authority.
(See SEGMENTS OF AN INSTRUMENT APPROACH PROCEDURE.)
a. U.S. civil standard instrument approach procedures are approved
by the FAA as prescribed under Part 97 and are available for public use.
b. U.S. military standard instrument approach procedures are
approved and published by the Department of Defense.
c. Special instrument approach procedures are approved by the FAA
for individual operators but are not published in Part 97 for public use.
(See ICAO term INSTRUMENT APPROACH PROCEDURE.)
INSTRUMENT APPROACH
PROCEDURE [ICAO]- 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.
INSTRUMENT APPROACH PROCEDURES CHARTS-
(See AERONAUTICAL CHART.)
INSTRUMENT DEPARTURE PROCEDURE (DP)- A preplanned instrument flight rule
(IFR) air traffic control departure procedure printed for pilot use in graphic
and/or textual form. DP's provide transition from the terminal to the
appropriate en route structure.
(See IFR TAKEOFF MINIMUMS AND DEPARTURE PROCEDURES.)
INSTRUMENT DEPARTURE PROCEDURE (DP) CHARTS-
(See AERONAUTICAL CHART.)
INSTRUMENT FLIGHT RULES- Rules governing
the procedures for conducting instrument flight. Also a term used by pilots and
controllers to indicate type of flight plan.
(See VISUAL FLIGHT RULES.)
(See INSTRUMENT METEOROLOGICAL CONDITIONS.)
(See VISUAL METEOROLOGICAL CONDITIONS.)
(See ICAO term INSTRUMENT FLIGHT RULES.)
INSTRUMENT FLIGHT RULES
[ICAO]- A set of rules governing the conduct of flight under instrument
meteorological conditions.
INSTRUMENT LANDING SYSTEM- A precision instrument approach system which
normally consists of the following electronic components and visual aids:
INSTRUMENT METEOROLOGICAL CONDITIONS- Meteorological
conditions expressed in terms of visibility, distance from cloud, and ceiling
less than the minima specified for visual meteorological conditions.
(See VISUAL METEOROLOGICAL CONDITIONS.)
(See INSTRUMENT FLIGHT RULES.)
(See VISUAL FLIGHT RULES.)
INSTRUMENT RUNWAY- 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.)
INSTRUMENT RUNWAY [ICAO]- One of
the following types of runways intended for the operation of aircraft using
instrument approach procedures:
a. Nonprecision Approach Runway-An instrument runway served by
visual aids and a nonvisual aid providing at least directional guidance
adequate for a straight-in approach.
b. Precision Approach Runway, Category I-An instrument runway
served by ILS and visual aids intended for operations down to 60 m (200 feet)
decision height and down to an RVR of the order of 800 m.
c. Precision Approach Runway, Category II-An instrument runway
served by ILS and visual aids intended for operations down to 30 m (100 feet)
decision height and down to an RVR of the order of 400 m.
d. Precision Approach Runway, Category III-An instrument runway
served by ILS to and along the surface of the runway and:
1. Intended for operations down to an RVR of the order of 200 m
(no decision height being applicable) using visual aids during the final
phase of landing;
2. Intended for operations down to an RVR of the order of 50 m
(no decision height being applicable) using visual aids for taxiing;
3. Intended for operations without reliance on visual reference
for landing or taxiing.
Note 1: See Annex 10 Volume I, Part I, Chapter
3, for related ILS specifications.
Note 2: Visual aids need not necessarily be matched to the scale of nonvisual
aids provided. The criterion for the selection of visual aids is the conditions
in which operations are intended to be conducted.
INTEGRITY- The ability of a system to provide timely warnings to users when
the system should not be used for navigation.
INTERMEDIATE APPROACH SEGMENT-
(See SEGMENTS OF AN INSTRUMENT APPROACH
PROCEDURE.)
INTERMEDIATE APPROACH SEGMENT [ICAO]- That segment of an instrument approach
procedure between either the intermediate approach fix and the final approach
fix or point, or between the end of a reversal, race track or dead reckoning
track procedure and the final approach fix or point, as appropriate.
INTERMEDIATE FIX- The fix that identifies the beginning of the intermediate
approach segment of an instrument approach procedure. The fix is not normally
identified on the instrument approach chart as an intermediate fix (IF).
(See SEGMENTS OF AN INSTRUMENT APPROACH PROCEDURE.)
INTERMEDIATE
LANDING- On the rare occasion that this option is requested, it should be
approved. The departure center, however, must advise the ATCSCC so that the
appropriate delay is carried over and assigned at the intermediate airport. An
intermediate landing airport within the arrival center will not be accepted
without coordination with and the approval of the ATCSCC.
INTERNATIONAL AIRPORT- Relating to international flight, it means:
a. An airport of entry which has been designated by the Secretary
of Treasury or Commissioner of Customs as an international airport for customs
service.
b. A landing rights airport at which specific permission to land
must be obtained from customs authorities in advance of contemplated use.
c. Airports designated under the Convention on International Civil
Aviation as an airport for use by international commercial air transport
and/or international general aviation.
(Refer to AIRPORT/FACILITY DIRECTORY.)
(See ICAO term INTERNATIONAL AIRPORT.)
INTERNATIONAL AIRPORT
[ICAO]- Any airport designated by the Contracting State in whose territory it is
situated as an airport of entry and departure for international air traffic,
where the formalities incident to customs, immigration, public health, animal
and plant quarantine and similar procedures are carried out.
INTERNATIONAL CIVIL AVIATION ORGANIZATION [ICAO]- A specialized agency of the
United Nations whose objective is to develop the principles and techniques of
international air navigation and to foster planning and development of
international civil air transport.
1. African-Indian Ocean Region
4. Middle East/Asia Region
INTERNATIONAL FLIGHT INFORMATION
MANUAL- A publication designed primarily as a pilot's preflight planning guide
for flights into foreign airspace and for flights returning to the U.S. from
foreign locations.
INTERROGATOR- The ground-based surveillance radar beacon
transmitter-receiver, which normally scans in synchronism with a primary radar,
transmitting discrete radio signals which repetitiously request all transponders
on the mode being used to reply. The replies received are mixed with the primary
radar returns and displayed on the same plan position indicator (radar scope).
Also, applied to the airborne element of the TACAN/DME system.
INTERSECTING RUNWAYS- Two or more runways which
cross or meet within their lengths.
INTERSECTION-
a. A point defined by any combination of courses, radials, or
bearings of two or more navigational aids.
b. Used to describe the point where two runways, a runway and a
taxiway, or two taxiways cross or meet.
INTERSECTION DEPARTURE- A departure
from any runway intersection except the end of the runway.
INTERSECTION TAKEOFF- (See INTERSECTION
DEPARTURE.)
IR- (See IFR MILITARY TRAINING ROUTES.)
I SAY AGAIN- The message will be repeated.