Landing is one of the most critical phases during a flight. It’s the second thing pilots learn in training after basic flight controls and recovery techniques. I’d love to be able to describe how to make a perfect landing, but the truth is a ‘perfect’ landing, as opposed to a good safe landing, probably doesn’t exist. Or is at least 99% luck. What I can describe are 5 main elements that make a good, and therefore safe landing.
1. A soft landing is not necessarily a good landing
One of the biggest fallacies out there is that a smooth landing is a good one. This isn’t always true. Whilst it does make the ride more comfortable for our passengers, unless conditions are perfect and the runway is long, a soft landing can be a bad thing. Touchdown is the first opportunity we have to dump all the kinetic energy keeping the aircraft aloft.
If the touchdown is very soft, the airplane is still half-flying, meaning it still needs to be controlled carefully, taking more time to disperse the remaining energy through braking over a limited length of runway. It’s also better for the wheels, as a smooth landing will scrape off the initial point of contact of the tires along the runway before friction spins the wheels up to the same speed as the aircraft.
2. Wet runways need a positive landing
Once again, unless the runway is very long, a wet runway deserves a ‘positive’ landing. This means the pilot will endeavor to make a firm touchdown onto the runway. It’s because at our landing speed (anywhere between 220 to 280 km/h), the water on the runway can’t disperse away from under the tires in a soft landing, and the wheels will instead ‘skate’ on top of the water’s surface (hydroplaning).
A firm landing ensures the wheels, under the force of the touchdown, will break through this water film and make contact with the runway tarmac, which is far less slippery.
3. The landing isn’t over until you’re down to taxi speeds
Some of you might have experienced a flight where the moment the aircraft touches the tarmac, people start clapping. Funny enough, this isn’t the end of the landing. Although it’s very rare at that point for anything to go wrong, the airplane is still traveling at great speed, and is therefore still somewhat unstable. For instance, any sudden gust of wind could make one or even both of the wings airborne again. This is why when we land the plane, we still use the flight controls to keep the aircraft centered and down on the runway until it’s slowed down a lot more.
4. It’s the wheel brakes that are most effective in slowing the aircraft down during landing
A lot of things happen just after touchdown. Lift dumper panels open up on the wing to act as ‘air brakes’, the pilots engage the engine’s ‘reverse thrust’ (diverting bypass air being sucked in by the engine’s fan out and forward through panels midway along the engine), and once the nose wheel is on the ground you’ll feel the pilots use the main-wheel brakes.
Out of all three, it’s the brakes that make the most difference in slowing the aircraft down. Reverse thrust and lift dumpers are useful in the first few seconds of touchdown before the nose touches down, as they use the force of the high speed airflow that comes with the airplane’s landing speed. Once the airplane has slowed down however, they quickly become less effective. This is why during landing once the nose wheel is down, you’ll notice the main wheel braking the most out of all three.
5. Automatic landings still need a human
One of my favorite myths is that pilots are lazy and fly the airplane on the autopilot the whole time, even during landing. It’s far from the truth, as although aircrafts are able to land automatically, it’s intended to be used in conditions of bad visibility (as in fog and mist). In fact, our wind limitations for landing are severely reduced if we need to carry out an automatic landing, so it’s fortunate that it’s very rarely foggy and blustery at the same time.
This is because the automatic pilot uses control algorithms based on information from navigation radios on the ground and air sensors on the airplane. There is no level of prediction or anticipation incorporated. The autopilot can’t expect the airplane to sink a bit more, or see a gust of wind rustle grass as it rushes towards the runway. For this reason, even when landing on automatic pilot, one of the pilots will still be holding, ‘ghosting’ the controls in case it does something undesired, ensuring the landing is completed safely. And most other landings are almost always done manually by one of the two pilots.
There are plenty of other things that come into play when landing an aircraft. It’s fair to say the list is much longer. These five tend to be the biggest questions my fellow pilots and I get when talking to people about flying. I hope I’ve cleared up any misconceptions, and perhaps next time you fly KLM to somewhere with a short runway, you won’t feel so bad about the landing not being completely unnoticeable.