General Operating Procedures — Page 73, Lesson 55

I want to walk you through a few important procedures that fall under general operating procedures in communications. Let's start with the transponder codes you need to know for emergencies. The communication failure code is 7600, and the hijack code is 7500. These are standard transponder squawk codes that you set on your transponder to alert air traffic control to your situation without needing to say a word on the radio. Now let's talk about the orbit. Occasionally, air traffic control needs to gain separation between your aircraft and an aircraft ahead of you. They do this by having you make a complete turn through 360 degrees. That full 360-degree turn is called an orbit. Here's how it sounds on the radio. The controller might say: "G-CD, FOR SEPARATION, ONE ORBIT LEFT." You would read back: "ONE ORBIT LEFT, G-CD." After you complete that orbit, your aircraft then resumes its original heading. There's a different meaning if the instruction simply says "G-CD ORBIT RIGHT" without specifying "one orbit." That means the aircraft is to continue orbiting to the right until advised otherwise by the controller. So "one orbit left" means exactly one turn and then resume heading, while "orbit right" with no number means keep turning until told to stop. Next, let's look at traffic information and avoidance. Whenever traffic appears to be conflicting with your aircraft — what the controller calls the "target" aircraft — the controller should pass information to you in a specific format. That format includes several pieces of information. First is the relative bearing, using the clock code. That means the controller tells you where the traffic is relative to your aircraft's nose, using the face of a clock. For example, "10 o'clock" means 60 degrees to your left. Second is the range, given in nautical miles, or NM. Third is the direction of flight. The controller will use specific terms: closing, converging, diverging, parallel, same direction, opposite direction, overtaking, crossing left to right, or crossing right to left. Fourth is the relative speed, if the controller knows it. Here's a typical traffic information report to a pilot: "Oxford 94, unknown traffic 10 o'clock 6 miles, crossing left to right, height unknown fast moving. If not sighted turn left heading 270." Your readback would be: "Left heading 270, Oxford 94." Now, avoiding action is different from just traffic information. Avoiding action is given by the controller whenever they consider that there would be a collision risk if no action was taken. This is a direct instruction to maneuver, not just information. For example: "Oxford 94, avoiding action turn left immediately heading 270, traffic right 2 o'clock same level converging." Your readback: "Left heading 270, Oxford 94." When the risk has passed, the controller will say: "Oxford 94, resume own navigation." Your readback: "Wilco, Oxford 94." "Wilco" means "will comply" — you acknowledge and will follow the instruction. Finally, let's look at conditional clearances. These are given by ATC in a specific format with three parts. First is the call sign of your aircraft. Second is the condition — the situation that must be satisfied before the clearance applies. Third is the clearance itself — the instruction you are authorized to carry out once the condition is met. This format ensures there is no confusion about what you are cleared to do and under what circumstances.