Special Operational Procedures and Hazards — Page 156, Lesson 244

I want to walk you through the start of Chapter 10, which covers Special Operational Procedures and Hazards. We're beginning with the Departure Climb — the phase right after takeoff where noise and obstacle clearance are critical. Let's start with the first rule: procedures shall not be executed below a height of 240 metres, which is 800 feet, above aerodrome elevation. That means you don't start any special departure procedure — like a noise abatement profile — until you're at least that high above the airport's altitude. Below that, you're in the initial climb phase and you fly a standard, safe profile. Next, the procedure specified by an operator for any one aeroplane type should be the same for all aerodromes. So if you fly a Boeing 737 for your airline, the departure climb procedure you use at London Heathrow should be the same as the one you use at Dubai — consistency across all airports for that aircraft type. There will be no more than two departure procedures to be used by one operator for an aeroplane type. One of these is identified as the normal procedure, and the other as the noise abatement procedure. So you have a standard way out, and a quieter way out — but only two, not a dozen different profiles. Normal departure procedures typically include one of the two examples in the appendix to this chapter — so there are reference profiles in the back of the book that illustrate what a standard departure climb looks like. Now, a critical safety point: all necessary obstacle data shall be made available to the operator, and the procedure gradient shall be observed. That means the airline must have the obstacle information for every airport they fly to, and the climb gradient required to clear those obstacles must be followed. You don't just guess — you check the numbers. Here's an important operational flexibility: power settings to be used after engine failure, shutdown, or other reason for loss of performance during the procedure are at the discretion of the pilot, and noise abatement considerations no longer apply. If you lose an engine, you are no longer trying to be quiet — you are trying to stay airborne and clear obstacles. The pilot decides what power to use, and noise restrictions go out the window. Now, the minimum level of thrust for the flap and slat configuration, after you've reduced power, is the lesser of two values: max climb power, and the power necessary to maintain the engine-inoperative net climb gradient. So you can't go below whichever of those two is lower — you need enough thrust to keep climbing safely if an engine fails. Those minimum thrust levels vary as a function of flap setting, altitude, and aeroplane mass, and they are included in the OM — the Operations Manual. The settings also need to take account of engine anti-icing where applicable, because ice protection bleeds off engine power, so the minimum thrust might need to be higher. There are conditions where these departure procedures are not to be used: if a windshear warning exists, or if you suspect windshear or downburst activity. In those conditions, you fly a standard, conservative departure — not a noise abatement profile. Finally, the maximum acceptable body angle specified for the aeroplane type shall not be exceeded. That's your pitch attitude limit — don't pitch up beyond what the aircraft is certified for, even if you're trying to climb steeply for noise reasons. Now let's move to the Approach section. When establishing noise abatement procedures on approach, the following requirements apply. First: the aeroplane shall not be in any configuration other than the final landing configuration at any point after passing the outer marker or 5 nautical miles from the threshold of the runway of intended landing, whichever is earlier. This is the Stabilized Approach concept. By that point, your gear should be down, flaps at landing setting, and you're fully configured to land. You don't change configuration after that point. Second: excessive rates of descent shall not be required. You shouldn't need to drop fast to meet the profile — that's unsafe and uncomfortable. Now, safety considerations for the glide path or approach angles: they should not require an approach to be made above the ILS glide path angle, above the glide path of the VASI (Visual Approach Slope Indicator), above the normal PAR final approach angle (Precision Approach Radar), or above an angle of 3 degrees, except when the ILS glide path itself requires higher. So the standard is 3 degrees — anything steeper is only acceptable if the ILS itself is built that way. Finally, the pilot should not be required to complete a turn onto final approach at distances less than will, in the case of visual operations, permit an adequate period of stabilized flight on final. In plain terms: you need enough straight final approach time to get the aircraft stable before landing — no last-minute turns close to the runway. That figure shows the CDFA — Continuous Descent Final Approach — which is the technique that supports these stabilized approach and noise abatement principles. You'll see the profile there on screen. That covers the departure climb and approach noise abatement procedures from this chapter.