Airspace Infringement at a Controlled Aerodrome
You are departing a controlled aerodrome in Brunei in a light single-engine aeroplane under visual flight rules. The tower clears you for take-off with a right turn after departure and a climb to 2,500 ft. Shortly after lift-off, the transponder shows a traffic advisory and the controller instructs you to stop the turn and maintain runway heading. You are in Class D airspace with a cloud base of 1,800 ft and visibility 6 km. Your company SOP requires an immediate turn to avoid a noise-sensitive area, which conflicts with the controller's instruction. You have a passenger who is a senior company manager and who questions why you are obeying the tower instead of the SOP.
1. Explain the hierarchy between the ATC instruction, the company SOP and the VFR weather minima, and state what you do.
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The hierarchy is clear and must be applied in order.
1. ATC instruction. In controlled airspace, an ATC clearance or instruction is mandatory unless an emergency requires otherwise. The controller has radar and traffic information you do not have; the instruction to stop the turn and maintain runway heading is a traffic-avoidance instruction and takes precedence over a noise-abatement SOP. The SOP is an internal commercial preference; the clearance is a regulatory requirement.
2. Weather minima. VFR flight in controlled airspace requires compliance with the applicable visibility and cloud-clearance minima. A cloud base of 1,800 ft with a planned level of 2,500 ft leaves only 700 ft of clearance beneath cloud, and the aircraft must remain clear of cloud with the required horizontal and vertical distance and in the required flight visibility. The controller's instruction to maintain runway heading may take you towards cloud or terrain, so you must monitor and, if the minima cannot be maintained, advise ATC immediately and request an amended clearance.
3. What you do. Comply with the instruction, acknowledge it readably, fly the aircraft, and once clear of the conflict advise ATC of your intended routing and request a turn that satisfies both the noise SOP and the traffic situation. Do not debate the SOP with the passenger in flight; explain afterwards. If at any point the minima cannot be maintained, declare the situation to ATC and request vectors or a clearance to climb.
2. The manager asks whether the noise SOP can be treated as a clearance. Answer him, and describe what the operator should do about the conflict.
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No. An SOP is an internal procedure; it cannot authorise a deviation from an ATC clearance, and it cannot override the rules of the air. Only the controller can vary a clearance, and only the commander can deviate from a clearance in an emergency, which must then be reported.
The operator should treat this as a systemic issue, not a one-off. The noise SOP should be rewritten to state explicitly that it applies only when consistent with the ATC clearance and the applicable minima, and that ATC instructions prevail. The operator should also review whether the SOP's departure turn is compatible with the published departure procedures at that aerodrome, and brief crews accordingly. The event should be recorded in the operator's safety reporting system so that the conflict is visible to the safety manager rather than resolved informally by individual crews.