Expectation of Clearance

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Article Information
Category:	Air Ground Communication
Content source:	SKYbrary
Content control:	EUROCONTROL

Contents 1 Description 2 Hazards 3 Typical Scenarios 4 Contributory Factors 5 Solutions

Description

Many situations in air traffic control are repetitive and result in pilots expecting that a particular clearance will be given, because:

• That particular clearance is habitually given in similar situations; or,

• That clearance is stipulated in the Flight Information Publications.

Hazards

If a clearance is actally given which differs from the expected clearance, the pilot may read back the clearance correctly but perform the expected clearance.

Alternatively, the pilot may read back the expected clearance, but the error may not be noticed by the ATCO.

Typical Scenarios

• The standard instrument departure (SID) specifies a climb to 5,000 ft. The pilot is cleared to 4,000 ft. The pilot correctly reads back the clearance but climbs to 5,000 ft (Level Bust).

• The pilot is normally cleared to follow a specific taxi route to the stand, which involves no stops. The ATCO clears the pilot to taxi by a different route and instructs him/her to wait at a particular point. The pilot fails to stop at the specified point.

Contributory Factors

• Repetitive rostering of pilots on the same route schedules, so that they become over-familiar with them;

• Passing non-standard clearances when standard clearances exist and are satisfactory.

Solutions

• Issue standard clearances whenever possible;

• If a non-standard clearance is necessary, this status must be emphasised.