Control of Aircraft — Page 337, Lesson 446

Let's pick this up right where the information flow to the pilot happens. We're looking at the aerodrome controller's job of making sure the pilot has everything they need before they move. First, the big rule: the aerodrome controller must give the pilot adequate and accurate aerodrome information before the pilot uses the aerodrome. And here's a key detail — when wind information is passed, the direction is given in degrees magnetic. That's so the pilot can relate it directly to the aircraft compass, which reads magnetic heading. No mental conversion needed. Now, the information is broken into three phases. Let's go through each. Prior to Taxi. Before the pilot even starts moving, they're told: - What runway is in use - The surface wind direction and speed - The aerodrome QNH — that's the barometric pressure setting for the aerodrome, so the altimeter reads height above the aerodrome - The air temperature for the runway to be used — and note this is only for turbine engine aircraft. That's because turbine performance is very sensitive to temperature - The visibility in the direction of take-off, or the RVR — the Runway Visual Range - And the correct time Prior to Take-off. Right before departure, the pilot gets: - Any significant changes in wind conditions, air temperature, visibility, or RVR — so if anything has shifted since the taxi briefing, they hear it now - And significant meteorological conditions in the take-off and climb-out areas — unless the pilot has already been informed Prior to Entering the Traffic Pattern. Before entering the traffic pattern or starting an approach to land, the pilot is given: - The runway to be used - The surface wind direction and speed - And the aerodrome QNH So you can see the pattern — the runway, the wind, and the QNH are the core items that get repeated at each phase. Now, Alerting Service — this is a separate duty. The aerodrome controller is responsible for activating the aerodrome crash rescue and firefighting service when required. If necessary, the controller can suspend all visual circuit traffic for the duration of an emergency situation. And here's an important chain of command: the aerodrome controller may suspend the visual circuit on the instructions of the Area Control Centre, if an aircraft in an emergency is likely to land at the aerodrome. And there's a specific time limit to note. If an aircraft has been cleared to land but fails to do so within 5 minutes after the landing clearance has been given — well, that's where the excerpt cuts off, but that's the trigger point we're tracking. So the key ideas here: the three briefing phases, the magnetic wind, the turbine-only temperature, and the controller's emergency authority with that 5-minute marker.