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Operations

Controlled airspace

En route

Aircraft deviations in controlled airspace – advice to ATC  AIP ENR 1.1

In controlled airspace, separation standards are based on the pilot maintaining track as closely as possible at all times. Corrective action must be taken to regain track as soon as any deviation is observed.

Additionally, the pilot must immediately notify ATC if the aircraft is found to be off track by any of the deviations described below:

LLZ/VOR
Half-scale deflection or more of the CDI
NDB
±5° or more from the specified bearing
DME
± 2 nm or more from the required arc
RNAV
Half scale deflection of the CDI or IDEV as appropriate
GPS
If the indicated displacement from track centreline exceeds ±2 nm
VISUAL
More than 1 nm from the cleared track


The values above must not be interpreted as defining a sector within which the pilot is permitted to navigate.

Deviations from route or track

In controlled airspace, any deviation from route or track requires prior clearance from ATC, except in an emergency. The values given in previous paragraphs must not be interpreted as tolerances within which deviations from route or track without clearance are permitted.

Deviations due to weather


In controlled airspace, any diversion from route or route or track due to weather requires prior clearance from ATC. If unable to obtain a clearance (for example, due to being out of radio contact) and the pilot in command considers that the deviation is necessary, a PAN call specifying details of the deviation must be broadcast on the appropriate frequencies.

Pan Pan, Pan Pan, Pan Pan, Zulu Foxtrot Romeo, 15 nautical miles south of Normanton, 8500, is descending immediately to 500 feet to avoid cloud’.

Pilots must be aware that the declaration of an emergency does not guarantee the aircraft safe passage, especially if the deviation is into an active restricted area.

Change of levels in controlled airspace AIP ENR 1.7


The pilot in command must commence a change of level as soon as possible, but no later than one minute after receiving that instruction from ATC, unless that instruction specifies a later time or place. ATC may require that an assigned level must be reached by a specific time, distance or place. If a pilot in command doubts that the requirement can be met, advise ATC immediately.


A requirement to report at a time or place given in the same clearance as a descent/climb instruction does not require the new level to be reached by the specified time or place.

The pilot in command of an aircraft operating in controlled airspace must report:

  • when the aircraft has left a level at which level flight has been conducted in the course of a climb, cruise or descent and
  • when the aircraft leaves a level for which ATC has requested a report.

ATC may provide vertical separation between two climbing aircraft, not otherwise separated, by means of a step-climb. Pilots in command, who are subjected to a step-climb, must adopt the following procedure:

  • the pilot in command of the lower aircraft must report approaching each assigned level in the sequence and
  • the pilot in command of the higher aircraft, on hearing the lower aircraft report approaching each assigned level, must report the last vacated level.

Step-descents are the reverse of the above paragraphs. ATC may specify a rate of climb or descent. Other considerations are as follows:

  • the phrase ‘STANDARD RATE’ when included in a clearance, specifies a rate of climb or descent of not less than 500 ft per minute, except that the last 1000 ft to an assigned level must be made at 500 ft per minute and
  • in the case of a step-climb or descent, the specified rate will be applicable to all level clearances issued in the course of the step-climb or descent. If unable to comply with the prescribed rate, the pilot in command must advise ATC.

Block levels AIP ENR 1.7

Cruise climb is not used in Australian-administered airspace. Where possible, block level clearances will be issued upon request.

At the pilot’s request, a flight may be cleared to operate within controlled airspace within a block level—provided that other aircraft are not denied the use of airspace within that block. A glider or balloon cleared to operate in controlled airspace will be assigned block levels.

The pilot has complete freedom to change levels within the block, provided that the upper and lower levels are not exceeded. However, a clearance to operate within a block level will be cancelled or amended if another aircraft requests the use of a level within the block.

When cancelling or amending a block level clearance, the aircraft operating in a block level will be instructed to climb or descend to an appropriate level or block level in order to provide vertical separation from other aircraft requesting one of the levels. Aircraft at standard flight levels will be afforded priority over aircraft using non standard flight levels.

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