background image

Pilot/Controller Glossary 

6/17/21 

IF

 

(See INTERMEDIATE FIX.) 

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.) 

(Refer to AIM.) 

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

 Title 14 Code of Federal 

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 proce-
dures, or both to assist pilots in avoiding obstacles 
during climb to the minimum en route altitude. Those 
airports are listed in FAA/DOD Instrument Approach 
Procedures (IAPs) Charts under a section entitled 
“IFR Takeoff Minimums and Departure Procedures.” 
The FAA/DOD IAP chart legend illustrates the 
symbol used to alert the pilot to nonstandard takeoff 
minimums and departure procedures. When depart-
ing IFR from such airports or from any airports where 
there are no departure procedures, DPs, 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 Way-

point. 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. 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. Special Authorization Category I. An ILS 
approach procedure which provides for approach to 
a height above touchdown of not less than 150 feet 
and with runway visual range of not less than 1,400 
feet, HUD to DH. 3. 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 (with 
autoland or HUD to touchdown and noted on 
authorization, RVR 1,000 feet).

 4. Special 

Authorization Category II with Reduced Lighting. 
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 with autoland or HUD to touchdown 
and noted on authorization (no touchdown zone and 
centerline lighting are required).

 5. 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 

PCG I