background image

12/2/21 

Pilot/Controller Glossary 

b. 

The ILS localizer signal pattern usually 

specified as the front course or the back course. 

(See BEARING.) 
(See INSTRUMENT LANDING SYSTEM.) 
(See RADIAL.) 

CPDLC

 

(See CONTROLLER PILOT DATA LINK 

COMMUNICATIONS.) 

CPL [ICAO]

 

(See ICAO term CURRENT FLIGHT PLAN.) 

CRITICAL ENGINE

 The engine which, upon 

failure, would most adversely affect the performance 
or handling qualities of an aircraft. 

CROSS (FIX) AT (ALTITUDE)

  Used by ATC 

when a specific altitude restriction at a specified fix 
is required. 

CROSS (FIX) AT OR ABOVE (ALTITUDE)

 Used 

by ATC when an altitude restriction at a specified fix 
is required. It does not prohibit the aircraft from 
crossing the fix at a higher altitude than specified; 
however, the higher altitude may not be one that will 
violate a succeeding altitude restriction or altitude 
assignment. 

(See ALTITUDE  RESTRICTION.) 
(Refer to AIM.) 

CROSS (FIX) AT OR BELOW (ALTITUDE)

 

Used by ATC when a maximum crossing altitude at 
a specific fix is required. It does not prohibit the 
aircraft from crossing the fix at a lower altitude; 
however, it must be at or above the minimum IFR 
altitude. 

(See ALTITUDE  RESTRICTION.) 
(See MINIMUM IFR ALTITUDES.) 
(Refer to 14 CFR Part 91.) 

CROSSWIND

 

a. 

When used concerning the traffic pattern, the 

word means “crosswind leg.” 

(See TRAFFIC PATTERN.) 

b. 

When used concerning wind conditions, the 

word means a wind not parallel to the runway or the 
path of an aircraft. 

(See CROSSWIND COMPONENT.) 

CROSSWIND COMPONENT

 The wind compo­

nent measured in knots at 90 degrees to the 
longitudinal axis of the runway. 

CRUISE

 Used in an ATC clearance to authorize a 

pilot to conduct flight at any altitude from the 
minimum IFR altitude up to and including the 
altitude specified in the clearance. The pilot may 
level off at any intermediate altitude within this block 
of airspace. Climb/descent within the block is to be 
made at the discretion of the pilot. However, once the 
pilot starts descent and verbally reports leaving an 
altitude in the block, he/she may not return to that 
altitude without additional ATC clearance. Further, it 
is approval for the pilot to proceed to and make an 
approach at destination airport and can be used in 
conjunction with: 

a. 

An airport clearance limit at locations with a 

standard/special instrument approach procedure. The 
CFRs require that if an instrument letdown to an 
airport is necessary, the pilot shall make the letdown 
in accordance with a standard/special instrument 
approach procedure for that airport, or 

b. 

An airport clearance limit at locations that are 

within/below/outside controlled airspace and with­
out a standard/special instrument approach 
procedure. Such a clearance is NOT AUTHORIZA­
TION for the pilot to descend under IFR conditions 
below the applicable minimum IFR altitude nor does 
it imply that ATC is exercising control over aircraft 
in Class G airspace; however, it provides a means for 
the aircraft to proceed to destination airport, descend, 
and land in accordance with applicable CFRs 
governing VFR flight operations. Also, this provides 
search and rescue protection until such time as the 
IFR flight plan is closed. 

(See INSTRUMENT APPROACH 

PROCEDURE.) 

CRUISE CLIMB

 A climb technique employed by 

aircraft, usually at a constant power setting, resulting 
in an increase of altitude as the aircraft weight 
decreases. 

CRUISING ALTITUDE

 An altitude or flight level 

maintained during en route level flight. This is a 
constant altitude and should not be confused with a 
cruise clearance. 

(See ALTITUDE.) 
(See ICAO term CRUISING LEVEL.) 

CRUISING LEVEL

 

(See CRUISING ALTITUDE.) 

CRUISING LEVEL [ICAO]

 A level maintained 

during a significant portion of a flight. 

PCG C