Rules of the Air — Page 104, Lesson 168

Right, we’re moving into the heart of the Rules of the Air now. I want to walk you through the operational rules that govern how we actually fly in relation to other traffic and the airspace structure. We’re going to start with cruising levels, then get into the right-of-way rules, which are the core of collision avoidance. First, cruising levels. This is about how we express our vertical position. The rule is that for flights at or above the lowest usable flight level, or where applicable, above the transition altitude, flights shall be conducted in terms of flight levels. So above that point, we use flight levels — that’s the standard pressure setting, 1013.25 hectopascals, giving us a pressure altitude. Below the lowest usable flight level, or at or below the transition altitude, flights shall be conducted in terms of altitude. So below that transition, we’re using altitude — that’s height above mean sea level, based on the local QNH setting. The key distinction here is the transition altitude: below it, we talk in altitude; at or above it, we talk in flight levels. This ensures everyone is on the same reference so separation is consistent. Now, the right-of-way rules. Rule 6.13 sets the foundation: an aircraft shall not be operated in such proximity to other aircraft as to create a collision hazard. That’s the absolute baseline — you must not get close enough to create a hazard. The aircraft that has the right of way shall maintain its heading and speed. So if you have right of way, you hold your course and speed — you don’t deviate. But — and this is critical — the pilot-in-command is still responsible for avoiding collisions, including acting on ACAS alerts. Right of way does not absolve you of responsibility. The aircraft that is obliged to give way must do so, and must avoid passing over, under, or in front of the other aircraft unless it is well clear. And you must take into account the effect of wake turbulence. So giving way isn’t just about lateral separation — it’s about not cutting across the other aircraft’s path, and being aware of the turbulence they leave behind. Let’s look at the specific encounter scenarios. First, approaching head-on, rule 6.14. When two aircraft are approaching head on, and there is a danger of collision, each shall alter course to the right. Neither has right of way. So both aircraft turn right — that’s the standard, both deviate to their right, creating separation. No one has priority here; both act. Next, converging, rule 6.15. This is when two aircraft are converging at approximately the same level. When they are of the same type — and note, this uses the definition of aircraft — the aircraft that has the other on its right shall give way. So if the other aircraft is on your right, you give way. To do this properly, you should pass behind the other aircraft — not over, under, or in front — and to achieve that, the aircraft giving way should turn right. So the method is always to turn right and pass behind. Now, where the two aircraft are not of the same type, there’s a priority order. Let me give you that hierarchy, and again, the method of giving way is to turn to the right: - Power-driven heavier-than-air aircraft — that’s aeroplanes — shall give way to airships, gliders, and balloons. - Power-driven lighter-than-air aircraft — airships — shall give way to gliders and balloons. - Gliders shall give way to balloons. - Power-driven aircraft shall give way to aircraft which are seen to be towing other aircraft or objects. So the least manoeuvrable has priority. Balloons are at the top — everyone gives way to them. Then gliders, then airships, then aeroplanes at the bottom. And there’s a special note: a towing combination is considered to be a single flying machine, not an ICAO definition, under the control of the pilot-in-command of the towing aircraft. So when you see an aircraft towing a glider or an object, treat the whole combination as one aircraft, and it has priority over power-driven aircraft. Finally, overtaking, rule 6.16. An overtaking aircraft is defined as an aircraft that approaches another from the rear on a line forming an angle of less than 70° with the plane of symmetry of the latter. So imagine the aircraft in front — its plane of symmetry is the vertical plane running nose to tail. If you approach from behind at an angle of less than 70° to that plane, you are overtaking. At night, the approaching aircraft would see the white tail light of the aircraft in front — that’s your cue. The aeroplane being overtaken has the right of way, and the overtaking aircraft — whether climbing, descending, or in horizontal flight — shall keep out of the way by altering its heading to the right, and maintain that position relative to the other aircraft until well clear. So you overtake on the right, and you stay there until you’re well clear. That’s the core of the right-of-way rules. The recurring theme is: turn right, pass behind, and never cut in front unless well clear. Let’s move on to the next part.