General Principles - Landing — Page 289, Lesson 361

Let's pick up with the landing technique itself. I want to walk you through the touchdown and rollout procedure, because this is where the pilot's actions directly determine whether the aeroplane stops in the distance available. First, arm the auto spoilers and auto brakes as appropriate. That ensures a prompt stopping effort right after touchdown. Now here's a critical distinction: for aeroplanes fitted with automatic anti-skid brakes, the brakes will be applied above the dynamic hydroplaning speed. But for aeroplanes without that system, you only apply the brakes below the dynamic hydroplaning speed. Let me unpack that. Dynamic hydroplaning is when the tyres ride on a film of water and lose contact with the runway — braking above that speed on a wet runway is ineffective and dangerous. The automatic anti-skid system can manage brake application above that speed safely, but without it, you must wait until you're below that speed before you touch the brakes. The flare should lead to a firm touchdown — sometimes described as flying the aeroplane onto the runway. Positive landings help place load on the wheels, which increases braking effectiveness and squeezes the water out from the tyre footprint area. So a firm touchdown isn't just about comfort; it's about getting the tyres in contact with the runway surface. Do not allow the aeroplane to float, and do not attempt to achieve a perfectly smooth touchdown. An extended flare will extend the touchdown point — you'll land further down the runway than planned. Soft touchdowns delay wheel spin-up and delay oleo compression, and both of those are needed for auto brake and auto spoiler activation. So a soft touchdown actually delays your stopping systems. After main gear touchdown, do not hold the nose wheel off the runway. Smoothly fly the nose wheel onto the runway by relaxing aft control column pressure. Then deploy spoilers as soon as possible after touchdown, or confirm auto spoiler deployment. If the aeroplane does not have auto brake, then initiate braking once the spoilers have been raised and the nose wheel has contacted the runway. Apply the brakes smoothly and symmetrically. Initiate reverse thrust as soon as possible after touchdown of the main wheels, and target the rollout to stop well short of the end of the runway. Leave a margin for unexpectedly low friction due to wet rubber deposits or hydroplaning. Now let's move to microbursts and windshear. Of all the phases of flight, it's the landing phase that's most susceptible to severe weather conditions. The low altitude, low speed, low thrust settings, and high drag during the landing phase mean the aeroplane is at its most vulnerable. Landing when windshear is observed or forecast should be avoided. But if conditions are within limits, then landing at a higher speed should be used — with caution, since the higher landing speed will greatly increase the distance of the airborne section and the ground roll of the landing. That figure shows a microburst at an airfield — a severe downdraft that spreads out horizontally when it hits the ground, which is exactly the kind of windshear hazard that makes the landing phase so dangerous.