NFC Learning

Preliminary Report. The communication used for the prompt dissemination of data obtained during the early stages of the
investigation.

“pressure altitude” means an atmospheric pressure expressed in terms of altitude
which corresponds to that pressure in the Standard Atmosphere as defined in Annex
8 to the Chicago Convention

Prevailing visibility. The greatest visibility value, observed in accordance with the definition of “visibility”, which is reached
within at least half the horizon circle or within at least half of the surface of the aerodrome. These areas could comprise
contiguous or non-contiguous sectors.

Note.— This value may be assessed by human observation and/or instrumented systems. When instruments are installed,
they are used to obtain the best estimate of the prevailing visibility.

Primary frequency. The radiotelephony frequency assigned to
an aircraft as a first choice for air-ground communication
in a radiotelephony network.

Secondary frequency. The radiotelephony frequency assigned
to an aircraft as a second choice for air-ground communication
in a radiotelephony network

Primary radar. A radar system which uses reflected radio
signals.

Primary surveillance radar (PSR). A surveillance radar
system which uses reflected radio signals

“private aircraft” means an aircraft which is neither a commercial transport aircraft
nor an aerial work aircraft

PRMs - Persons with reduced mobility

“problematic use of substances” means the use of one or more psychoactive substances by
aviation personnel in a way that constitutes a direct hazard to the user or endangers the
lives, health or welfare of others or causes or worsens an occupational, social mental or
physical problem or disorder

Procedure altitude/height. A specified altitude/height flown operationally at or above the minimum altitude/height and
established to accommodate a stabilized descent at a prescribed descent gradient/angle in the intermediate/final approach
segment.

Procedure turn. A manoeuvre in which a turn is made away from a designated track followed by a turn in the opposite direction
to permit the aircraft to intercept and proceed along the reciprocal of the designated track.

Note 1.— Procedure turns are designated “left” or “right” according to the direction of the initial turn.
Note 2.— Procedure turns may be designated as being made either in level flight or while descending, according to the
circumstances of each individual procedure.