background image

Pilot/Controller Glossary

3/29/18

PCG I

−3

conduct these approaches. ATC utilizes an enhanced
display with alerting and, with certain runway
spacing, a high update rate PRM surveillance sensor.
Use of a secondary monitor frequency, pilot PRM
training, and publication of an Attention All Users
Page are also required for all PRM approaches.

(Refer to AIM)

IM

(See INNER MARKER.

)

IMC

(See INSTRUMENT METEOROLOGICAL

CONDITIONS.)

IMMEDIATELY

− Used by ATC or pilots 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.

INCREASED SEPARATION REQUIRED (ISR)–
Indicates the confidence level of the track requires
5NM separation. 3NM separation, 1 1/2NM
separation, and target resolution cannot be used.

INCREASE SPEED TO (SPEED)

(See SPEED ADJUSTMENT.)

INERTIAL NAVIGATION SYSTEM (INS)

− 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 (INREQ)

− A request

originated by an FSS for information concerning an
overdue VFR aircraft.

INITIAL APPROACH FIX (IAF)

− The fixes

depicted on instrument approach procedure charts
that identify the beginning of the initial approach
segment(s).

(See FIX.)
(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/she 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.)
(Refer to AIM.)

INNER MARKER BEACON

(See INNER MARKER.)

INREQ

(See INFORMATION REQUEST.)

INS

(See INERTIAL NAVIGATION SYSTEM.)

INSTRUMENT APPROACH

(See INSTRUMENT APPROACH

PROCEDURE.)

INSTRUMENT APPROACH OPERATIONS
[ICAO]

− An approach and landing using instruments

for navigation guidance based on an instrument
approach procedure. There are two methods for
executing instrument approach operations:

a.

A two

−dimensional (2D) instrument approach

operation, using lateral navigation guidance only;
and

b.

A three

−dimensional (3D) instrument approach

operation, using both lateral and vertical navigation
guidance.

Note: Lateral and vertical navigation guidance

refers to the guidance provided either by:
a) a ground

−based radio navigation aid; or

b) computer

−generated navigation data from

ground

−based, space−based, self−contained

navigation aids or a combination of these.

(See ICAO term INSTRUMENT APPROACH

PROCEDURE.)

INSTRUMENT APPROACH PROCEDURE

− A

series of predetermined maneuvers for the orderly

2/28/19

Pilot/Controller Glossary