NFC Learning

Recognition of alternative means or prior qualifications.

‘Critical Altitude’ (piston engines) means the maximum attitude at which, in standard atmosphere, it is possible to maintain, at a specified rotational speed without ram, a specified power or a specified manifold pressure. Unless otherwise stated, the critical altitude is the maximum altitude at which it is possible to maintain, without ram, at the maximum continuous rotational speed, one of the following:-

a. The maximum continuous power, in the case of engines for which this power rating is the same at sea level and at the rated altitude.

b. The maximum continuous rated manifold pressure, in the case of engines the maximum continuous power of which, is governed by a constant manifold pressure.

‘Critical Engine’ means the engine whose failure would most adversely affect the performance or handling qualities of an aircraft.

Critical phases of flight in the case of aeroplanes means the take-off run, the take-off flight path, the final approach, the missed approach, the landing, including the landing roll, and any other phases of flight as determined by the pilot-in-command or commander;

Critical phases of flight in the case of helicopters means taxiing, hovering, take-off, final approach, missed approach, the landing and any other phases of flight as determined by the pilot-in-command or commander.

A flight between a point of departure and a point of arrival following a pre-planned route using standard
navigation procedures.

“cruise climb” means an aeroplane cruising technique resulting in a net increase in altitude
as the aeroplane mass decreases.

“cruise relief pilot” means a flight crew member who is assigned to perform pilot
tasks during cruise flight to allow the pilot-in-command or a co-pilot to obtain
planned rest.

“cruising level” means a level maintained during a significant portion of a flight;

Culture. All man-made features constructed on the surface of the Earth, such as cities, railways and canals.

Recommendation.— An area of thunderstorms and cumulonimbus clouds should be considered:

a) obscured (OBSC) if it is obscured by haze or smoke or cannot be readily seen due to darkness;

b) embedded (EMBD) if it is embedded within cloud layers and cannot be readily recognized;

c) isolated (ISOL) if it consists of individual features which affect, or are forecast to affect, an area with a maximum
spatial coverage less than 50 per cent of the area concerned (at a fixed time or during the period of validity); and

d) occasional (OCNL) if it consists of well-separated features which affect, or are forecast to affect, an area with a
maximum spatial coverage between 50 and 75 per cent of the area concerned (at a fixed time or during the period of
validity).