I was recently asked to identify the most difficult aspects of handling a plane. I think a more interesting question would be which of the three main manoeuvres – taxiing, takeoff or landing – is the most challenging.
The truth is that there is no definitive answer; different pilots find each of these three phases of flight challenging in different ways, and this is largely influenced by the pilot’s personal flying experience, the type of aircraft he or she is flying, as well as environmental conditions. In fact, an airline, general aviation or helicopter pilot would justifiably have different views.
From my perspective as an airline pilot, the answer is most certainly the landing aspect of the flight. Let me elaborate on the three phases – taxiing, takeoff and landing – and the unique challenges each poses.
TAXIING FOR TAKE OFF
It is a common perception that a flight begins with a takeoff and concludes with a landing. This couldn’t be further from the truth. The fact is that a flight actually commences at the parking bay, from the moment a plane taxis on its own power right up to takeoff, and only concludes after it lands on the runway in its intended destination and taxies to its parking bay.
A good taxi is smooth and follows the centre line of the taxiway or runway. Big planes such as the Airbus A380 and Boeing 777 have cameras to guide them. Smaller aircraft, however, lack this luxury and in the absence of technical visual assistance, pilots have to rely on their own expertise to remain centered on the runway and anticipate turns on the ground.
Taxiing in poor visibility is often an uphill task for a pilot. I once landed in Zurich, Switzerland, in bad weather conditions and had to request for a ‘Follow Me’ truck to guide me to the appropriate parking bay.
When the weather is good though, taxiing a plane is relatively easy. The captain merely turns a tiller (steering wheel) with the left hand at low speed, and then transfers to using the rudder (a control surface, similar to that used to steer a boat) pedals with the feet to maintain the centre line of the runway during takeoff.
UP, UP & AWAY!
The takeoff phase begins when the thrust levers (throttles) are applied, and the plane starts moving at a high speed and lifting off the ground. Large jet engines are very powerful, and normally, a reduced takeoff thrust is used to prolong engine life.
During takeoff, the plane accelerates to a lift off (rotation) speed prior to getting off the ground. The term ‘rotation’ is often used because the aircraft pivots around the axis of its main landing gear while still on the ground. The nose is then raised (rotated) to increase the lift generated by the airflow across the wings.
The speed needed for lift-off is relative to the motion of the air. For instance, a headwind reduces the ground speed needed for takeoff, as there is greater flow of air over the wings. Typical takeoff air speed for jetliners, depending on the weight, is in the 130 to 155 knots (150 to 180 mph or 240 to 280 km/h) range.
There are three important speeds that a pilot needs to take note of during takeoff. The first is the decision speed – this speed, in effect, marks the point after which an emergency stop is no longer possible, and the plane is committed to continue with the flight. So, if the pilot, for any reason, makes a decision to abort the takeoff, it must happen before the plane reaches this speed.
The second is the rotation speed, whereby the pilot moves the flight control slightly back towards him or her in order for the plane to lift off the runway. It is important for the pilot to precisely determine this speed; if a plane is rotated too early, its tail may scrape the runway.
The third is the safety speed; this is the speed at which the plane is able to become safely airborne even in the extremely unlikely event of engine failure. It needs to be emphasised that takeoff is a very safe procedure. The captain’s training requires that he or she knows exactly what to do based on the speed that the plane has attained, and as a stringent backup measure, engine failure exercises are frequently practised in the flight simulator.
AND WE HAVE TOUCHDOWN…
Generally, landing a plane is trickier than taking off, as there are many variables present in the environment. For instance, if the plane is estimated to land on a wintry day with poor visibility due to fog, a pilot has to plan for an automatic landing.
An auto landing, which is always monitored by the captain, is a very safe procedure as the flight computer guides the plane all the way till touchdown. An auto landing system is capable of landing the plane safely in very low visibility and cloud ceiling. In fact, without automation, many airports would be closed for landing during winter when foggy conditions are prevalent.
Landing a plane in windy conditions is a challenge for the best of pilots, and is therefore restricted according to the strength of crosswinds, which may cause difficulties. For example, for the Airbus A330, a limit of 40 knots is imposed for landing. And even within this limitation, strong crosswinds necessitate skillful handling by a pilot when landing a large aircraft. The pilot must make use of the rudder to keep to the runway centre line.
During touchdown in a cross-wind landing, the pilot then removes the drift (an effect caused by the wind blowing from the side) that the aircraft has been maintaining, in order to line up with the runway. Managing this manoeuvre during the landing stage requires expert coordination.
Another situation that tests a pilot’s skills is landing in high altitude airports. An improperly executed approach in this kind of airport can result in a hard or heavy landing, which will require that the aircraft be examined thoroughly to determine if repair or maintenance work is required. In one incident that involved a heavy landing in a remote high altitude airport, where the necessary maintenance was not available, the plane had to be flown back to the main airport with its landing gears extended! This was a pricey affair, as it not only involved repair costs, but the return flight with gears extended caused the plane to burn more fuel!
UNPREDICTABLE AS THE WEATHER
At the end of the day, whether the takeoff or landing is trickier greatly depends on the conditions that exist at the given point in time.
A manual landing is certainly more challenging, owing to variable environmental conditions, and while no commercial airliner is capable of taking off automatically, the landing can definitely be carried out entirely by automation. And if the destination airport is equipped with auto landing facilities, then, the plane’s inbuilt automation makes the touchdown a piece of cake!
Airlines are fully aware of the challenges faced by pilots, and safety being their number one priority, ensure that pilots receive intensive training in flight simulators and are always on top of their game.
For me, landing is my favourite part of a flight, as it means that I’ve safely flown my passengers to their destination. My daughter, on the other hand, loves takeoff, when the engine hums, building up into a crescendo, as a burst of power accelerates the plane into the sky!
Which is your favourite part of a flight?
Captain Lim Khoy Hing is a former AirAsia Airbus A320 and AirAsia X A330/A340 pilot who also used to fly the Boeing 777. He has logged a total of more than 25,500 flying hours and is now a Simulator Flight Instructor with AirAsia X. In his spare time, he shares his opinion on aviation issues with others. For more air travel and aviation stories, check out his website, ‘Just About Flying’ at www.askcaptainlim.com.
Captain Lim’s book, LIFE IN THE SKIES, which won third place in the Reader’s Choice Award at the Malaysia BookFest 2015, and its Mandarin version 【飞行日记】 are now available for purchase onboard all AirAsia and AirAsia X flights. Pre-book your copy at www.bigdutyfree.com. Enjoy these great collections of articles by a veteran aviator.