Airline crew get asked all sorts of questions, from the straightforward to the obscure. Here the Qatar Airways’ crew answers some of the posers from curious customers.
Many modern aircraft have a winglet or wing extension at the end of the wing. What is it for?
Without getting too technical, these extensions at the end of the wing help reduce drag and, as a consequence, improve the efficiency of the wing. This helps to save fuel, a very important consideration to keep costs down and reduce emissions.
The pressure differential between the upper and lower surface of the wing as it moves through the air creates lift. This is what enables aircraft to fly. At the end of the wings, however, this pressure differentiation results in a vortex, called wake turbulence, that can sometimes be so powerful it can pose a risk to following aircraft. The wingtip devices help recover some of this energy which would otherwise be wasted by smoothing the airflow across the upper wing near the tip.
How do pilots communicate with air traffic controllers when they may speak different languages?
All pilots and air traffic controllers communicate in a common language, English.
Why are aircraft pushed back from their parking places on the taxiway?
Quite simply aircraft are pushed back from their parking bays or stands because they can’t reverse.
Pilots sometimes tell passengers to fasten their seatbelts as they may encounter some turbulence. What exactly is turbulence and is it something to be worried about?
Think about a boat on a calm, glassy lake. There’s hardly any movement up or down. Similarly, when flying through undisturbed air, the flight is smooth, with no bumps.
Think about the same lake if the wind starts blowing, causing waves to form. The boat then starts to move up and down, as it rides the waves.
Turbulence occurs when air is disturbed by wind, weather and pressure differentials. As the aircraft moves through the turbulence it will bump up and down but does not lose its ability to fly.
Modern aircraft are structurally strong and built to withstand turbulence. Nonetheless, for the comfort of their passengers, pilots do their best to avoid particularly turbulent areas. We receive weather briefings and updates during the flight. Weather radar helps us avoid turbulence caused by weather and we also get updates from other aircraft and air traffic control about clear-air turbulence which cannot be seen on the radar. We can then go around it or fly at a different altitude to avoid it.
Why are cabin lights dimmed for take offs and landings and why must the window blinds be open?
The reason is so the light inside the aircraft approximates the conditions outside. This means your eyes don’t need time to adjust after you exit the aircraft. It is also required by regulation.
Why must my seat be upright during take offs and landings?
It is a regulatory safety requirement. When the seat is up it is locked, but not when it’s tilted back. Seats tilted back can also make it difficult for the passenger behind to leave the aircraft.
It’s also worth mentioning that when you put your seat back, be considerate to the person sitting behind you. Letting them know and making sure they don’t need to retrieve something from a bag under your seat or using the tray table to eat or work is just good manners. When you do put your seat back, don’t slam it down, do it gently.
Do the pilots always land the plane or can it land automatically?
Most of the landings we do are flown manually to ensure we keep up our skill levels. The remainder are autolands which are usually only used for landing in fog or poor visibility or for practising the slightly different procedures for automatic landings.
That does place the door to automatic and cross check mean?
This is a standard instruction and means the crew arm the inflatable slides so that these will deploy automatically should the door be opened. The crew members on each side of the aircraft check the opposite door to make sure it is set properly.
Why do my ears pop during takeoffs and landings?
It’s to do with the pressurisation of the aircraft. As it climbs the amount of oxygen in the air decreases. In order to keep the oxygen level up so you can breathe normally, the aircraft is pressurised.
As the air pressure changes in the cabin, the air in your inner ear has to adjust to the pressure around you. For most people this isn’t a problem, but it can sometimes cause some discomfort. The easiest way to equalise the pressure is to close your mouth and pinch your nose and breath out hard. If you are unable to equalise during the decent, don’t worry; your ears will naturally adjust after landing.
Why is my passport checked three times; at check-in, at border control and again at the gate?
Immigration officials want to check you have valid documentation for leaving the country. They are not concerned whether you have the right documentation for the country to which you are going.
Most airlines check your travel documents at check-in and again at the gate to ensure that you have all the necessary visas and documentation you require for the country to which you are travelling and the details on your passport match those on your ticket.
You could be detained and deported if you don’t have the right documents and the airline may face a hefty fine. That’s why it’s worth double checking.
What causes the rumbling sensation and vibration that sometimes happens before landing?
On approach to the runway the flight crew increases the amount of drag to ensure the aircraft is on the ideal approach path at the right speed. The most common way to do this is to extend the speed brakes, also called spoilers. The disruption in airflow causes a light rumbling sensation in the cabin and you may feel the aircraft drop very slightly as the rate of decent is increased. This is perfectly normal.
The other thing that happens on the approach is the landing gear is lowered. This causes an increase in noise and vibration as the wheels lower into the airstream. Again this is perfectly normal.
Do the crew have to check in?
Absolutely. Check-in time for short haul flights is an hour and 15 minutes and for long haul flights it’s an hour and 30 minutes. In practice pilots often arrive much earlier than that. To prepare thoroughly, we get to the aircraft between 40 minutes and an hour before the flight.