How Safe is Flying?

How safe is flying today?

How safe is flying? I used to get asked this a lot while I was training for my private pilots’ licence. My favourite response always used to be. “Well, the most dangerous part is the drive to the airport.”

Seriously though, it is a very good question. How safe is flying in those gigantic machines along with a few hundred other people coming along for the ride. Let’s face it, this isn’t a perfect world and things go wrong. When airliner accidents happen, they of course go spectacularly wrong. Larger aircraft, carrying more passengers flying faster. It seems a miracle any get through at all. But they do. In fact, travelling by air is one of the safest methods of transport available today.

As an example, in peak times there can be 5,000 commercial aircraft flying over the U.S.A. at any one time. Similar numbers are also over Europe and Asia. These flights all happen every day with little incident.

Air Crash Investigations

Air safety is no accident. Let’s turn that around. Ok, we know accidents happen, we see it on the news and of course those popular TV programs like Air Crash Investigation. It may seem like a lot of people taking ghoulish interest in a tragic event. The actuality is that accidents contribute more to air safety than almost anything else. When an accident happens, no matter how minor or major, investigators will examine the details until they are 100% sure of what the cause was. This can be a pains-taking process and sometimes takes a year or more.

The reason for this painstaking process is prevention. By investigating and determining the cause of an accident, processes or new methods in construction can be put in place to prevent a similar accident from occurring in the future. In this way, no accident is ever without benefit for future fliers. These benefits will manifest themselves as; new training procedures, new maintenance procedures or new construction procedures.

B Checks must be done in the aircraft hangar, whilst C and D checks must be done at a purpose built aircraft maintenance centre.

Aircraft Maintenance

Aircraft maintenance is a key component to the safety of flying. Each aircraft has strict guidelines set down by the manufacturer on how the specific aircraft should be maintained. In addition, there are strict guidelines set down by aviation authorities such as the FAA (Federal Aviation Authority) in the U.S. or EASA (European Aviation Safety Agency) in Europe as well as other national aviation bodies in other countries. These bodies set the minimum standard of maintenance procedures for aircraft in that country as well as those flying into that country.

These procedures are constantly being updated with new findings from accidents, incidents or new technology that comes into the industry. All this is in place to ensure that when you and I get on a plane, we can count on doing so in full safety.

Aircraft maintenance service intervals can be broken into 4 categories or checks plus the daily pre-flight inspection. The timing of each of these checks is generally determined by the amount of hours an aircraft has flown and/or the amount of flight cycles an aircraft has endured. A flight cycle is one take-off and one landing. Therefore a flight from Melbourne to London via Bangkok is 2 flight cycles.

How Safe is Flying is Determined By Aircraft Maintenance Checks

Daily Inspection

Prior to every days’ first flight, a visual inspection of the aircraft is carried out. This inspection is a methodical walk around performed by one of the pilots and is a check for any superficial damage or anomalies on the aircraft. The visual inspection looks for any outwardly obvious damage or inconsistencies that might render the airliner unsafe for flight that day.

  • The wings and skin are checked for damage caused by bird-strike or other foreign objects.
  • Moving parts such as flaps, ailerons and elevators are checked for any foreign objects that may impede their free movement.
  • Tyres and are checked for splits or excessive wear.
  • Brakes are checked for  foreign objects or cracking
  • Air intake ports are checked for foreign objects
  • Pitot and Static air intake tubes are checked for any blockage

These checks are continued throughout the day before every flight. You can rest assured that the pilots want to have a safe aircraft every bit as much as you do. Nobody likes surprises once you are in the air.

Airlines very carefully schedule the various maintenance checks to coincide with their due date whilst minimising time out of service for aircraft.

Like your car requires servicing according to the manufacturer’s manual, aircraft also have a stringent schedule for mandatory checks and servicing. Airlines must have very detailed documented procedures for every step of aircraft maintenance which must be followed to the letter and signed off. As part of their certification to be allowed to fly into and out of various countries, airlines must be able to show their maintenance procedures and how they are followed to ensure passenger safety. In this way the question, how safe is flying? can be answered, as safe as we can possibly make it.

Airliner maintenance and safety checks can be broken down into 4 different levels. These are commonly known as the; A, B, C and D checks.

A Check

Other than the Daily Inspection, the A Check is the lightest check and is performed the most often. Depending on the aircraft type and the kind of use it gets, the A Check is performed every 300 – 600 flight hours or every 200 – 300 flight cycles. Remembering that a flight cycle equals one take-off and one landing. If the aircraft is used on short domestic flights, for example, it is more likely the cycles will be the determining factor as these will build up more quickly versus the flying hours.

The A Check itself is generally carried out overnight while the aircraft is not in service to minimise any loss of revenue. Around 20 – 50 man hours are involved in this check and it can be carried out at the airport gate.

B Check

The B Check is a more intense check and needs to be performed in an aircraft hangar. The check is performed around every 6 months and depending on the aircraft type may require 120 – 150 man hours. A Checks can be incorporated into the B Check so that the aircrafts’ removal from flying schedules is minimised.

C Check

The C Check is a much more intense check and requires a lot more space. For this reason, it must be carried out at a designated maintenance base. Depending on the aircraft type, this check is required to be carried out every 20 to 24 months which is also influenced by the number of flying hours. Around 6,000 man hours will be required which may keep the aircraft out of service for 1 to 2 weeks. A much more in-depth check of the airframe is carried out while many components are removed for inspection or replacement.

This check is designed to capture any problems with corrosion and cracking before they become a problem, as well as replacing or servicing smaller components.

Early detection is the purpose of most of the checks performed during maintenance periods.

D Check

The D Check is by far the most intensive check performed on aircraft and is also known as the HMV (Heavy Maintenance Visit). This check is carried out around every 6 years and can take the aircraft out of service for 2 months. Like the C Check, the service must be carried out at a purpose built maintenance base with the appropriate facilities. The work can involve around 50,000 man hours and essentially is a total strip down of the aircraft. Often even the paint has to be removed to allow a detailed inspection of the aircraft skin, looking for cracking and corrosion.

Airlines will often use this opportunity to refresh or update the livery of the aircraft as well as refurbishing and updating the cabin interior.

The cost of performing a D Check is huge. Depending on the aircraft type, a ball park figure of 1 million US dollars is not unusual. For this reason, the number of maintenance bases in places like the US are few. Many airlines will fly their aircraft to locations where labour costs are lower to perform this check. This doesn’t mean the work is inferior, as the same stringent documented work processes are in place and supervised.

As a rule of thumb, an airliner generally has 3 D Checks in its working life. After the third, the aircraft value has diminished to the point where it is likely to be worth less than the cost of doing the next scheduled D Check. At this point, the airline normally decides to retire the aircraft.

Air safety is no accident, but a painstaking very highly controlled process.

Conclusion

How safe is flying? When we look at the number of flights that are achieved without incident every day, we can see that the expectation of arriving at our destination in one piece is almost a given. Almost, because nothing in life is guaranteed. The same could be said for walking or driving down to our corner store. There is an element of risk in simply being alive.

The airline industry, and in this I include airlines, airliner manufacturers and airport operators, take safety extremely seriously. Their reason for their existence depends on the public being comfortable with the answer to, how safe is flying? Flight, for most people, is the only time in their lives that they will be in an environment that is totally hostile to their being. Too cold, not enough air to breath, too far to fall and too fast. Air travel has to be seen to be going the extra mile to provide a safe environment.

By learning from every accident that occurs and using that knowledge in maintenance procedures or flight training procedures, bit by bit accident likelihood is being reduced.

Being on a commercial airliner is now one of the safest places to be.

I would love to hear your views or experiences around how safe is flying today. By all means, leave those comments below. Thank you for stopping by and reading how safe is flying..

What is the average plane speed of a modern airliner?

Average Plane Speed

How often have you sat aboard a jet airliner and wondered about the average plane speed and how it is arrived at? Why is it that different speeds are used at different stages of the flight and why do they climb to different altitudes each time you fly?

To answer this we have to look at the various factors that determine the answer.

Atmosphere

The atmosphere in which you will be flying is a very fluid environment and just like the sea, has established currents. Also like the sea, it has varying pressures with the highest pressure being at the Earth’s surface and that pressure decreasing the further we get from the surface until we reach the near vacuum of space.

The currents or winds and the changing pressure plays a huge part in the planning of flights and the way they are carried out. Some winds are a constant feature of the atmosphere. On the surface, we know of the Trade Winds that blow along the Equatorial regions. These winds were counted on by the early sailing ships and were so named as they blew the early traders to and from their destinations.

Air India Boeing 787 8 climbs out on a Sydney gray day.

Like the early traders, we still count on the wind to aid us in reaching our destinations more quickly. Since the advent of jet airliners in the 1950s which could fly much higher than their propeller ancestors, it was found there are very strong winds at those higher altitudes which were named the Jetstream. When flying with the Jetstream, one can easily add significant speed to the flight and reduce the flying time to the destination. The winds move slightly with the seasons but can be counted on to the extent that airlines schedule their flights taking into account a faster flight with the Jetstream and slower flight against the Jetstream.

Measurement of Aircraft Speed

When we ask the question, how fast is an aircraft going? There are several answers that can be given and it can be very dependent on the stage of flight the aircraft is in.

Average plane speed and Take-off

We are sitting on the runway in a shiny new Boeing 777 about to apply full power and commence our take-off run. We’ve done our calculations and with the weight of cargo and fuel, we expect the airliner to become airborne at, for example, 152 knots(nautical miles per hour).

Hold on a minute, what does that mean exactly?

Ok, the additional information we need is that the local wind on the runway is blowing in your face and you will take off into the wind. When you are taking off, you don’t care about how fast the wheels are spinning on the ground, you care about how fast the air is moving over your wings. For instance, if the wind is blowing in your face at 20 knots, you only need to achieve 132 knots ground speed before you can expect the aircraft to start flying. This makes for a shorter take-off run as you started with a bonus of 20 knots before you even applied engine power. If you decided to take-off with the wind in the other direction, you would start off with 20 knots of wind going the wrong way over your wings and therefore would require a longer take-off run. The result is you would take the tops off the car park shuttle buses on the perimeter road which is not approved.

So we have established that speed through the air is the governing factor of flight. This is measured and expressed as KIAS or Knots Indicated Air Speed. Simplistically this is measured by air rushing into a forward facing tube called a pitot head or pitot tube which channels the air into a bladder inside the Air Speed Indicator. The higher the pressure which is driven by the forward movement of the aircraft, the higher the bladder causes the dial to read. It is a little more complex than that but it gives the idea at least.

A breakdown of the basic phases of an airliner’s flight.

 

Climb Out

Now in the climb out phase, air traffic control will be aware of the flight plan you have lodged, however, their first priority is to get you into a traffic flow that will clear you from the airport area without banging into other flight traffic. You will be given an assigned altitude, compass heading and speed. At busy airports, this can be a long involved process and you may find yourself tracking all over the countryside, possibly even in the opposite direction to your intended destination.

During this phase of flight, the rule of thumb all over the world is that you must remain under 250 KIAS (Knots Indicated Air Speed). Remember this is your speed through the air and not across the ground, so if the same wind you had on the runway is still blowing at this level you will have a ground speed of 230 Knots if you fly against it, but if you turn around and fly with the wind you will be doing 270 knots ground speed.

The speed restriction is there to enable a safer control of aircraft in a constricted space. In some  cases, if it is not busy, air traffic control may release you from the speed restriction and allow you to go off on your merry way.

A Philippine Airlines Airbus A340-313X climbs out of Sydney. She is restricted to 250 KIAS and is under Sydney departure control.

Climb to Cruise Altitude

So long as the sky above you is not too congested you should get your clearance to climb to your desired cruise altitude and start on your actual journey. As we pass through 10,000 AMSL (Above Mean Sea Level) we can increase our speed from 250 KIAS to that recommended in our particular airliners manual. The rule of thumb is 300 KIAS.

You may wonder why we need to bother to climb to those high altitudes. Isn’t the view nicer down here where you can see something? There are a couple of answers to that:

Firstly, at higher altitudes, we can fly above most of the weather. This is a winner for the passengers who expect to have mostly smooth flying when they get on an aircraft. In the pre-jet days, aircraft were much more susceptible to the vagaries of the weather as they had to fly through storm clouds and the like which was very uncomfortable.

Secondly, the higher you climb, the thinner the air. This means an aircraft can pass though it with less air resistance and therefore can fly faster using less fuel. This not only makes the airline accountant happy, but also enables a long range aircraft to achieve that range. For example, if I loaded up my Boeing 777 with enough fuel to get from Singapore to London and then only flew at 10,000 feet of altitude. I would expect to be looking for an emergency landing site somewhere in Afghanistan as my fuel was about to run out.

A United Airlines Boeing 777-200ER taxis to runway 34L at Sydney. The 777 replaced the 747 on the US Australia routes as of 01 April 2014. The trans Pacific route is one of the worlds longer routes and demands careful balance between fuel and payload.

 

Initial Cruise

The logistics of managing a long range flight are quite complex. The object of the exercise is to take as much payload as we can and carry it over the distance required. Obviously for long range flights we need a significant amount of fuel which will make up a large proportion of our weight at take-off and initial climb out. You may have noticed on long haul flights you have been on, that you might climb to an altitude around 30,000 feet to start with and then after a few hours you may then climb to a higher altitude possibly approaching 40,000 feet.  There are two reasons for this:

Firstly, in the initial stages of flight with full fuel tanks the aircraft is too heavy to climb economically and safely past the early 30,000s. Doing so would burn more fuel trying to achieve the higher level. It could also put the aircraft in an unstable flight phase where a stall might be possible.

Secondly, pilots may change the altitude of the aircraft during flight from time to time to either make use of more favourable tail winds or to avoid unfavourable head winds.

Speed in the Cruise Phase of Flight

Once your aircraft reaches a certain height, the effectiveness of the ability to measure speed as KIAS (Knots Indicated Air Speed) begins to diminish. The air is now so thin that it can no longer provide accurate readings on the Air Speed Indicator.  This is where speed starts to be measured differently.

Most aircraft and modern airliners particularly, have their speed controlled by the autopilot. A speed is selected, 300 KIAS for example, and the aircraft happily flies with the auto pilot applying or reducing thrust to maintain the desired 300 KIAS. When the aircraft achieves an altitude of around 25,000 feet, and this varies slightly from aircraft to aircraft, the speed is automatically changed from KIAS (Knots Indicated Air Speed) to a Mach number.

What is a Mach Number?

A Mach number is an expression of speed relative to the speed of sound. For example, Mach 1 equals the speed of sound. Mach 0.5 is half the speed of sound, Mach 2 is twice the speed of sound. On top of that we need to add the complexity of the air temperature.  The speed of sound is not a constant value, but depends on the air it travels through for its’ speed. To illustrate this let’s take it to its’ extreme.

We know that in the sea, or water in general that sound travels long distances. Whales can communicate over long distances with their songs. The water molecules are dense and therefore will transmit the sound readily. At the opposite end of the spectrum, we can go into space and find that that it is almost silent. In the near vacuum there are few molecules available to help conduct sound.

This is why when you ask, what is the speed of sound? The answer will be 761.1 miles per hour / 661 knots / 1,225 kilometres per hour, with the qualifier being, at 15 degrees Celsius at sea level. This relates to the pressure of air which is governed by the altitude and by the temperature.

Using this knowledge we can understand that the higher you fly, the lower the speed of sound becomes.  If you look at the speed of sound at sea level and compare it with that at around 40,000 feet, you would see that it is around 90 knots slower at that height than at sea level. The fact that the temperature is much colder at 40,000 feet, around minus 56C, means that it is not as slow as it might be if the temperature was the same as at sea level.

Concorde is the only airliner to date that has achieved supersonic flight or flight that is beyond Mach 1. The design is very specific and the cost to run was enormous. The sonic boom generated by the shock waves ensured that this aircraft could only ever be used over water.

The only airliner to achieve greater than Mach 1 is the Concorde which was capable of Mach 2. This airliner was specifically designed to fly through the sound barrier as it used to be known. It took many attempts to break through this so called barrier as it calls for a totally different aircraft design. As an aircraft approaches the sound barrier, shock-waves start to build up on various surfaces of the aircraft. These have an adverse affect on the aircrafts’ forward movement and can negate any advantage of flying more economically through thinner air. If you persist on going faster still and get closer to the speed of sound, you will start to feel the aircraft start to buffet more and more violently until you reach a catastrophic failure of the air-frame and the aircraft breaks up.

Every aircraft comes with a Do Not Exceed speed, which indicates the air-frame is not built to sustain the possible pressures of those high speeds.

Transitioning to Mach Number

We are climbing through the mid 20,000s of feet of altitude and our auto pilot throttle control clicks over from KIAS to Mach.  It may be around Mach .50 or so depending on conditions and how many knots we were doing. Each airliner will have a maximum allowable Mach number and a cruise Mach number.  The cruise mach number is used to maximise the performance so we get the most economical flight results as well as keeping our aircraft within safe operating parameters. Too fast and we could bring on the buffeting which could break up the aircraft. Too slow and we could bring on a stall as the wing struggles to provide lift in the thinner air.

Typically most airliners operate in the Mach 0.71 to 0.85 range depending on the design.  To see the average plane speed for any of our featured aircraft be sure to look in the menu at the top of the page and select the Specs page for your desired airliner.

With the current flight information systems that most airlines offer, it is possible to see how fast you are flying and lots of other interesting statistics as you travel along. I always get a kick when we have a following wind to see how high the ground speed can get up to. Getting over 1,000 KPH always feels like a bonus to me.

Thanks for stopping by to find out a bit more about average plane speed. As you can see it is quite a complex answer to what appears to be a straight forward question.

I’d love to hear about your flight experiences, how fast have you gone? how high have you gone?

What causes turbulence, things that go bump in the flight?

What Causes Turbulence?

What causes turbulence you wonder as you sit there with your seat-belt hanked in as tight as a drum. Your white-knuckled hands gripping the armrests as if your life depended on it. There is no doubt that extreme in-flight air turbulence can be a very frightening experience. A large airliner shaking, dropping and rising can feel very dramatic, especially when our only view of the world is the inside of the cabin with no reference to the outside world in most cases.

Understanding what causes turbulence may go some way to alleviating the fear of it when it happens. Most of us, me included, always hope for a calm turbulence-free flight every time we board. In most cases, we are rewarded with just that, a calm flight with a few minor bumps along the way. But why does it happen?

Air Movement

The air in the atmosphere that surrounds us is fluid, just like the waters in the oceans, lakes and rivers. Like the waters in those environments, it never stops moving. External effects like the

What causes turbulence? Thermal activity resulting in towering cumulo-nimbus clouds are areas of high likelihood of turbulence.

heat of the sun and the spinning of the Earth ensure that the air is constantly in motion. It is always rushing from one place to the next, never still. You experience this yourself in the winds you feel. If you are on the coast you will be aware of sea breezes in the afternoon caused by the sun heating the land. The warmed air over the land rises and cooler air from over the water rushes in to take its place, creating that sea breeze.

Air movement is affected by large global influences, such as ocean or continental temperatures as well as local influences such as mountain ranges.

Consider your aircraft moves through the air much like a boat on the water.  It is subject to waves and eddies in the same way and moves with them, up and down, side to side, etc.. This is what we experience in the aircraft cabin.



4 Types of Air Turbulence

There are 4 basic types of air turbulence. In most cases these are predictable and pilots are aware of the situation before they commence the flight. Obviously when turbulence is known to exist, all possible will be done to avoid or at least minimise the exposure of the aircraft and passengers to the effects. This is not always possible.  Let’s have a look at the different types.

What causes turbulence? – Thermal

What causes turbulence? As the day heats up, warm moist air rises and creates unstable air as it mixes with cooler drier air above. This creates up and down draughts that can be quite violent.

As we mentioned earlier, the heat of the sun is a large cause for air movement in the atmosphere. Air rises as it starts to warm and pushes its way through cooler air in the upper atmosphere. This can lead to unstable moist air mixing with dry cooler air and creating up and down draughts. These are the kind of conditions experienced particularly in warmer climates where the heating can be quite extreme. In most equatorial regions where humidity is high on the surface, the thermal effect is quite evident by the formation of woolly clouds which may start towering into the upper atmosphere. This is where you can expect thunderstorms to start forming.

When you experience the aircraft dropping or rising, it is because it is flying through an air stream that is going up or down. They are sometimes called up draughts and down draughts. It may feel like the aircraft has stopped flying and is simply dropping out of the sky. In reality, the aircraft is still flying through the air, as it was in the still air, but that packet of air itself is moving. Of course, if the change from still to moving air is quick enough, the effects can be quite startling as gravity takes a while to catch up, if indeed it can. For this reason, you are always advised to keep your seat belt loosely fastened during flight. The aircraft may fly into a down-draught which can cause it to descend faster than gravity can pull you with it. In extreme cases food trolleys and cabin crew have been thrown against the ceiling during undetected turbulence.

What causes turbulence? – Ground Effect

As the air moves across the Earths surface, it may move unimpeded over oceans and fairly flat land. However, we know the Earths’ surface is not all flat. It is dotted with mountain ranges on a

What causes turbulence? Mountains have a significant effect on the air passing over them. Some of these effects can persist a long way down wind of the mountain itself.

large scale or man-made objects on a smaller scale. All of these features can contribute to creating varying levels of air turbulence. If you have ever been to the beach or even a river and watched the water pass over and around rocks, you will have a picture of how air also behaves around obstructions. The water gets all confused and turbulent at it meets and passes the obstacle. It can then take quite a bit of distance before the water stabilises back to a smooth flow again.

At high altitude, there is little effect, but sooner or later an aircraft has to descend or take off and possibly come into the affected area of ground effect turbulence. Some parts of the world are more susceptible to ground effect than others. For example, airfields located near mountain ranges, particular if they are downwind of those mountains. The air having passed over the mountain ranges swirls and eddies as it rolls down the downwind or leeward side. Like our rock in the stream of water, the air may be disturbed for tens of kilometres or more before it reverts to a steady and stable stream of air.

Another feature of ground effect turbulence is the up draught. Let’s look at our mountain range again. As the wind or packet of air contacts the mountains, it suddenly has nowhere to go. The air behind it is pushing it against the mountains and it finds the only way to go is up. This air can be pushed upwards at high force as the pressure of the air on contact with the mountains increases because the air behind keeps pushing it. This means the upward draught can go much higher than the mountains themselves which can result in something that feels like the aircraft has been punched from below.

A combination of thermal and ground effect can also produce significant turbulence. The way the sun heats different types of land can produce instability. Even over flat land with no hills nearby, the sun can heat fields that have been ploughed quite differently from those that have green crops growing on them. These fields in turn will heat the air above them which then begins to rise. Ploughed fields are usually mixed in with wooded areas and fields that have green crops, so you will find different parcels of land will heat air at different rates and some not at all. This creates an unstable air mass with some air rising faster than other cooler air and the swirling and eddying begins as they contact each other.

What causes turbulence? – Shear or Wind Shear

Shear, or wind shear is when two packets of air that border each other are travelling at different speeds and/or directions. This can be horizontally or vertically.

Flying within either of the air packets is no problem at all. The transition from one to another, on the other hand, can be uncomfortable and in some cases quite dangerous.

First, let us look at shear in a horizontal situation. Let’s say the air at 20,000 feet is travelling east at 20 knots, however, the air at and above 21,000 feet is travelling east at 70 knots. Where the two layers of air meet will be an area of turbulence as the air moving at 20 knots tries to slow the air above down to its speed and the 70 knot air tries to speed the 20 knot air up to its speed. There will be eddies and disturbances between the layers much like our rock in the stream.  Tumbling waves of air which will make for a bumpy transition.

What causes turbulence? Wind shear at low altitudes is dangerous for aircraft. Many airports have equipment to warn if such conditions exist in the area.

Still in our horizontal shear transition, the second factor that has to be watched for is the aircraft’s’ airspeed. Often the difference in speed between the two air packets can be quite high. This can present a problem. An aircraft has parameters around the speed that it needs to be flown. To slow, and the aircraft stalls and ceases to fly. Too fast, and the maximum air-frame speed might be exceeded. This needs to be avoided as bits could start to fall off which means a lot of paperwork and explanations to the next crew who need to fly this aircraft. Aircraft measure their speed through the air, irrespective of what that air is doing. So if the aircraft is doing the correct speed in the first air packet, then it transitions to the second, it will suddenly be flying faster or slower than before until it stabilises to the new air mass. In our example above with the 20 and 70 knot air packet speeds. An aircraft climbing from one to the other at 300 knots in the 20 knot air packet will suddenly be doing 250 knots when it enters the 70 knot packet.

The other form of shear, or wind shear is the vertical type.  This is when packets of air are rising or falling at significantly different rates. This type of shear is quite dangerous at lower altitudes as aircraft do not have as much separation from the ground to recover. Most airports have equipment in place to detect such events in the immediate locality to ensure safe departures and arrivals. These shears can be caused by thermal activity as described above, including thunderstorms which are often preceded by a micro-blast containing extremely strong and volatile winds. Some have strong enough down-draughts that a jet airliner can’t out-climb them.

What causes turbulence? – Aerodynamic

What causes turbulence? The effects of wake or aerodynamic turbulence are beautifully illustrated here as this aircraft passes through clouds.

Aerodynamic or wake turbulence is the disturbed air left behind an airplane. If you have ever looked behind a moving boat or ship, you will be familiar with the wake it leaves behind. Waves travelling outwards the further away it gets. If another boat of equal or lesser size crosses this wake, it can be quite a rough ride for it.

So it is with aircraft. As wings move through the air and create lift, they also create drag which causes a wake of disturbed air. For this reason, very strict protocols exit for air traffic controllers when they direct aircraft at or near airports. There is a system of minimum time separation for aircraft taking off and landing which relates to the size of the leading and the following aircraft. For example, a business jet flying directly behind an Airbus A380 would likely have its wings ripped off. Drastic, but you get the picture.

What causes turbulence and how is it avoided.

Like most things, preparation and avoidance are the best tools when it comes to dealing with turbulence. In most cases, weather forecasters are able to predict when and where turbulent conditions may exist. This information is passed on to the pilots and flight planners. They will, where possible, plan flights to avoid these areas, or at least aim for the most moderately affected areas.

What causes turbulence? Weather forecasting is a very important factor in ensuring the safest flight plans can be made to avoid turbulence.

Communication between pilots and between pilots and air traffic control is a very important way of creating awareness of turbulence areas. Weather forecasting can tell you so much, but sometimes un-forecast conditions can exist. The sharing of that information will enable aircraft that follow behind to either be prepared or perhaps even detour around the affected area.

Weather radar is another way to see ahead and be warned of possible adverse weather. Large airliners have a forward facing radar built into the nose of the aircraft. This radome, which is a shortening of the words, radar dome, is a forward facing radar that looks at the weather ahead. Most weather patterns involve some sort of moist air and from this, the radar can see where there might be adverse weather conditions ahead, particularly thunderstorms. Based on this information the pilot can decide to fly around, under or over a particular weather situation, providing air traffic control requirements allow for this.

CAT or Clear Air Turbulence is harder to detect. This is the kind of turbulence that catches everyone unawares. There is no moisture that helps detect its existence and it is a very good reason to keep that seat belt on loosely during the whole flight.

What Causes Turbulence – Conclusion

Like water, the air is a very fluid environment. In most parts of the world, most of the time, we can traverse this environment without incident. We have to accept, however, that it is still a natural environment that can be unpredictable and also hostile to us.

By understanding what conditions can cause turbulence, we are better able to predict when and where it might occur. In addition, we have technology in place that can sense many types of turbulent air and enables us avoid those areas. Not all turbulence can be predicted or sensed before being encountered, so there will always be the risk of experiencing some turbulence.

Although it may appear that your aircraft is a fragile contraption, the strength built into it is extraordinary. During the certification testing of a new airliner, one of the tests is to break the aircraft’s’ wings.  That involves bending the wings to an insane level until they break. The pass mark is for the wing to be able withstand at least twice as much pressure as the worst imaginable turbulence. Most airliners pass this with a very generous amount of leeway.

Understanding what causes turbulence is one of the many things that keeps flying safe.

We would love to hear any experiences you might have had with in-flight turbulence. How did it make you feel? Was it dramatic? Feel free to comment below.

Sydney Welcomes American Airlines Boeing 777 300ER

Boeing 777 300ER Publicity Flight Prior to the American Airlines Sydney Service.

It might have been Friday the 13th, but Sydney turned on a stunning morning for the publicity visit of the American Airlines Boeing 777 300ER twin jet. This Boeing 777 had flown overnight from Hong Kong after completing a Dallas to Hong Kong service and added in a side trip to Sydney to promote the new direct American Airlines service between Los Angeles and Sydney. After an absence of 2 decades American Airlines returns to these shores working in concert with Australian carrier, QANTAS.


The aircraft was flown empty from Hong Kong to Sydney with just two pilots on board. With an arrival around 08:30am into Sydney and a departure around 10:00pm that evening, the pilots used their thirteen and a half hours in Sydney to sleep, before flying the return sector to Hong Kong.  

American Airlines Boeing 777 300ER Sydney Fly Over

Air traffic was at acceptable levels and Sydney tower approved a low level pass over the air field by the giant Boeing 777 300ER twin jet. Descending to 1,800 feet she came in from the south and did a slow fly over the field along the runway 34 left centre line. She then continued on and did an west to east pass over Sydney Harbour before returning back over the sea to land on runway 34 left. 

Brand New Boeing 777

This American Airlines Boeing 777 300ER registration N734AR is under a month old with its first

Front view of the General Electric GE GE90-115B engine which is currently the largest turbo fan jet engine in the world.

flight having been on 15 October 2015. It was delivered to American Airlines in Dallas / Fort Worth on 26 October 2015. Powered by 2 giant General Electric GE GE90-115B engines which are currently the largest turbo fan jet engines in the world, the Boeing 777 has a very impressive presence. The engines themselves are rated to produce 115,300 lbs of thrust or 510 kilo Newtons. 

Walking around underneath the 777, one gets some perspective of the actual size of this aircraft. I was fortunate enough to be able to have an up close and personal look, whilst she was housed in hanger 96 at Sydney airport for publicity visits by the press, as well as representatives from the travel industry. If the size didn’t impress, the newness certainly did.

Rear view of the General Electric GE GE90-115B engine which is currently the largest turbo fan jet engine in the world.

Shiny new painted tail of American Airlines Boeing 777 300ER, Registration N734AR.

Under the Boeing 777 tail looking forward.

Less than a month old and this American Airlines 777 was as shiny as a new pin.

Huge engine in take on the largest turbojet engine in the world powers this American Airlines Boeing 777 300ER

This newness was even more evident when entering the cabin from the rear door. That feeling of getting into a new car. 

On Board the American Airlines Boeing 777 300ER

There are basically 4 classes in the American Airlines 777 300ER. Main Cabin, Main Cabin Extra,

American Airlines Boeing 777 300ER Main Cabin. Seats are in 3x3x3 configuration.

Business Class and First Class. In the Main Cabin the configuration is 9 seats across the cabin width in a 3 x 3 x 3 setup. In Main Cabin Extra there is an additional 6 inches of legroom in the same seating style. Both Business and First Class are set up in a herring bone alcove configuration which gives each seat the feeling of privacy. All classes can enjoy 250 movies, 130 TV shows, 18 radio channels and 380 music albums. Each seat also has AC outlets as well as USB connections, so you will be able to have your devices fully powered during flight and charged up for arrival. For an additional cost, WiFi is also available. The dome on top of the aircraft fuselage is the receiver for satellite internet which drives the WiFi connection.

Boeing Sky Interior

The cabin itself is presented in Boeings’ new sky format, with contoured ceilings and LED lighting. This interior gives a feeling of space and coupled with the fully controllable LED lighting

Boeing Sky Interior LED lights change the look and feel of the cabin with dimming and colour changes.

Boeing Sky Interior soothing colours.


has a calming and relaxing effect. Whilst walking through, each cabin had slightly different colours being emitted by the lighting which was quite effective. The feeling of space created by the contoured ceilings and luggage bins, was not done at the expense of the storage space. I found the overhead luggage bins to be quite generous in size and well able to accommodate the wheelie bags that have become the the favourite of todays’ traveller.

The average flying time between Sydney and Los Angeles is around fifteen and half hours which can vary due to winds aloft.  The new 777 300ER certainly looked like it would make for comfortable ride with plenty of entertainment to pass the long journey. 

One thing I did notice and if I was travelling as a couple I would try and get these seats.  There are two together next to the window instead of the usual 3 if you go to row 30, seats A and C. I believe the opposite side would be the same and would be row 30, seats H and J. They seemed to be able recline even though the bulkhead is behind them. If anyone tries these, be sure to leave us a message below and give your thoughts and experiences.

Seats 30 A and C look good if you are travelling as a couple. Two across instead of three.

 

 

Thank you for stopping by.

Airbus A350 Service

Qatar Airways, the A350 Launch Customer

Today marks 10 months since Qatar Airways, the A350 launch customer received their first Airbus A350 XWB.  Pressing it into service between Doha and Frankfurt on the 14 of January 2015, Qatar Airways became the first airline in the world to offer passengers the Airbus A350 service.  This has been a long road for Airbus, from conception to testing and finally production. The video of the A350 journey below sums it up very well.

Qatar now has 4 of the 43 Airbus A350 900s it has on order.  In addition Qatar also has 37 of the larger Airbus A350 1000s on order.

The 4 A350s now in service carry the following tail numbers: A7 ALA, A7 ALB, A7 ALC, A7 ALD. These aircraft are used primarily on the  Doha to Frankfurt and Doha to Singapore routes at the following times.

Qatar Airways A350 XWB Timetable

Flight Number Origin Destination Departure Arrival
QR 069 Doha Frankfurt 01:20 06:55
QR 070 Frankfurt Doha 11:25 18:25
QR 067 Doha Frankfurt 08:00 13:35
QR 068 Frankfurt Doha 15:40 22:40
QR 938 Doha Singapore* 07:00 19:50
QR 939 Singapore* Doha 21:20 23:55

As you can see it is still quite a rarity to be able to actually see, let alone fly on an A350. If you are lucky enough to be able do either, we would love to hear from you and hear your thoughts below in comments.

Second Operator of Airbus A350 Vietnam Airlines

Whilst Vietnam Airlines is the second operator of the A350, the actual ownership of their aircraft lies with aircraft leasing company, Aercap Holdings N.V. based in the Netherlands.  The first aircraft joined the fleet on 01 July 2015 and was used on the Hanoi to Ho Chi Min City (Saigon) domestic route for familiarisation and testing. Vietnam Airlines has now received two of the 10 A350 900s they have on order.  These two aircraft are registered as: VN-A886 and VN-A887.  The current routes served by the these 2 aircraft include, Ho Chi Min City, Hanoi, Seoul and Paris.

Air Vietnam the second of the A350 operators. This A350 941, registration VN-A886 was their first aircraft, delivered on 01 July 2015.

Once again if you can get a chance to photograph these aircraft, feel free to upload them to our Airliner Photo page.

Boeing 787 vs Airbus A350

Boeing 787 vs Airbus A350Boeing 777 vs Airbus A330, I hear a lot of questions in this vein.  Which is better?  Which flys further, higher, carries more passengers and which is the more advanced?

Airliners are like tools in a tool box which an airline can choose to use on routes appropriate to the traffic demand. Some routes are relatively short and don’t require airliners that have a long range, or ability to fly a long distance.  If the pair of cities being linked are large then there might be a demand for more frequent flights by smaller airliners rather than fewer flights by larger airliners.  This allows the airline to offer business travellers a wider choice of departure times which reduces time wastage waiting for inconvenient less frequent departure times.  At peak times a much larger airliner might be used to ensure maximum uplift of passengers at those times.


It is critical to an airline that they have the right tools for the tasks that they intend to undertake.


It is critical to an airline that they have the right tools for the tasks that they intend to undertake.  Like any business, airlines have to control expenses, so once again the right tool is essential.  This is why many airlines have a mixture of airliner types. These different airliners are used on routes that they are specifically designed for, and can perform the task with the minimum of overhead expense.

The Airbus A350 XWB takes off on its maiden flight on 14 June 2013 from Aéroport de Toulouse-Blagnac.

Let’s look at the two newest offerings from the top two airplane makers, Boeing and Airbus.  Both aircraft manufacturers have come out in the last few years with new models that are technological leaps forward.  The Airbus A350 XWB (eXtra Wide Body) and the Boeing 787 Dreamliner.  These two airliners represent the competition between Airbus and Boeing to have the best offering in the market.  But  mostly they represent the demands by their airliner customers for a more advanced and economical tool for their airliner tool box.  Economy is the driving factor.


Economy is the driving factor.


Particularly since the the 2008 doubling of the oil price, airlines have been looking for ways to reduce their fuel bill and therefore protect their margins.  On the other side of the equation, the proliferation of Low Cost Carriers has put downward pressure on airfares and airlines are having to ensure their aircraft are full in order to make sure they show a profit.

An Asiana Airbus A330-300 rotates for take-off at Sydney.

These two newest airliners employ new techniques such as the use of composite materials to reduce weight, single piece fuselage sections to  reduce the number of fasteners which once again reduces weight.  Weight reduction of course reduces the amount of fuel burn required to carry a payload from A to B.  Coupled with enhanced passenger comforts to make them more attractive to the travelling public, these airliners are setting the bar for the future of air travel.

Both the Boeing 787 and the Airbus A350 come in 3 variants.  This ensures that the models are a very versatile offering to the market and the same design can be used for many different scenarios.  This also highlights the fact that the giant twin engined jets are now the mainstay of passenger aviation.  We have seen the demise of the Airbus A340 which was a 4 engined version of the Airbus A330.  This was produced at a time when twin jets were still getting approvals for long over water flights, but with the present level of engine technology this is no longer an issue.  We may even see the end of the 747 and A380 if a recession hits as some would suggest.


remember that there are different variants of each airliner model


So, when we talk about Boeing 787 vs Airbus A350 or Boeing 777 vs Airbus A330, we have to remember that there are different variants of each of those models.  Let’s look at range to start with.  Obviously if an airline has long over water routes, then they will need airliners with a long range ability.  The economics have to add up as you may end up with a flying tanker with a few passengers on board.

In ascending order the maximum ranges of the largest of todays’ twin jet airliners.

Although we can see that Boeings’ 777 offers the shortest and the longest range, the airliner models are fairly evenly spread through the various niche markets as relates to range.  The Boeing 777X, which I have not yet included here, as design specs are only now just being finalised, will have a range of 17,220Km which is up there with the Boeing 777 200LR.

A Virgin Australia Boeing 777-300ER taxis at Sydney Kingsford Smith Airport. These aircraft are used on the Australia to US trans-Pacific route.

So we know how far theses airliners can fly relative to each other, but unless we know what they can carry over that distance, the information is a little pointless.  So below we have a table to show the relative passenger numbers as well as the Maximum Takeoff Weight (MTOW) for each.

A list of the large twin jet airliners with their maximum take off weights (MTOW) expressed in kilograms and their maximum passenger numbers when configured in a typical 3 class configuration.

We can see here also that there are niches for each of the airliner models,  for each Boeing there is an Airbus offering that does relatively the same job and vice versa.  If you look at an aircraft that carries a heavier load you can go to the range chart above and it will probably have a lesser range, unless of course it is a specially built extended range variant.  You can also notice that for example the Boeing 777 200 and Boeing 777 200ER (Extended Range) carry the same amount of passengers, however the 777 200ER has a higher maximum takeoff weight.  This of course is to lift the additional amount of fuel that gives it the extended range ability.

This mix of attributes ensures that all niches in the Very Large Airliner (VLA) market are addressed.  Large capacity – short distance, large capacity – long distance, small capacity – long distance, small capacity – short distance.

Aircraft
Model and Variant
Range Passenger Capacity (typical 3
class)
Maximum take off weight (MTOW)
(tonnes)
Fuselage Length (metres) Wing Span (metres)
Airbus A330 200 13,430 293 233.00 58.82 60.30
Airbus A330 300 10,830 335 230.00 63.69 60.30
Airbus A350 800 15,700 270 248.00 60.54 64.75
Airbus A350 900 15,000 314 268.00 66.89 64.75
Airbus A350 1000 15,600 350 308.00 73.88 74.75
Boeing 777 200 9,700 301 247.20 63.70 60.90
Boeing 777 200 ER 14,310 301 297.55 63.70 60.90
Boeing 777 200 LR 17,370 301 347.50 63.70 64.80
Boeing 777 300 11,120 365 299.37 73.90 60.90
Boeing 777 300 ER 14,690 365 351.50 73.90 64.80
Boeing 787 8 15,200 242 228.00 56.70 60.10
Boeing 787 9 15,700 280 251.00 62.80 60.10
Boeing 787 10 13,000 323 251.00 68.30 60.10

The table above shows the different relationships between capacity, length and wing span.  In the case of the Boeing 777, the LR and ER extended range variants use additional wing size to enable higher lift as well as accommodating more fuel storage space.

To find out more details about each airliner type, click on the airliner name in the table above.

Thank you for taking the time to read about these airliners.  We would love to hear any comments you might have and any ideas to make this site more useful to you. These can be left below.

The mystery of Malaysia Airlines Flight 370

Where is Malaysia Airline MH370

Every year it seems the world is getting smaller with us humans taking up more and more space.  The feeling is, where can you go that is not crawling with people already, is there any wild unconquered territory anywhere anymore?

Contrast that with trying to find a huge airliner that we know has crashed into the sea.  The oceans are still vast and for the most part do not have their floors charted.  I am not just talking about MH370, but also Air France flight AF447 which crashed into the mid Atlantic on a flight from Rio de Janeiro to Paris in June of 2009.  Air France followed a logical route from Rio to Paris so the searchers had a a fairly good fighting chance of knowing where to look.  How long did that search take?  Two Years!  Two years of theories and counter theories before finally a result was arrived at.

The tail section of the Air France flight AF447 is found floating in the mid Atlantic.

So, back to MH370.  We all know the story inside out by now.  Well we have suffered through the theories, reports of sightings and satellite hand shakes.  In a few days it will be 18 months since the tragic accident that left behind anguished and frustrated relatives and friends of the victims.  What progress has been made in the search for the Boeing 777?

Millions have been spent by countries like Australia and China in the search of the Indian Ocean.  However, the biggest breakthrough has to be the discovery of the flaperon on a remote beach on the remote island of Reunion in the western Indian Ocean.  I must admit to being a doubter when I first heard the theory of the aircraft coming down in the Indian Ocean.  This was an area so far and completely in the wrong direction from the intended flight path that it made the whole idea seem fanciful and surreal.  I must admit to being skeptical right up until the time the flaperon was found.

The Malaysian Airliners Flight 370 flaperon is taken away by authorities on Reunion Island to be sent to Toulouse France for investigation.

I’m not an oceanographer but I couldn’t understand how an aircraft full of floating objects such as seat squabs, neck pillows and flotsam could disappear so completely.  I could not believe that a Boeing 777 could be easily be landed on water(assuming anyone was still alive to do so) in one piece.  Yes we know the story of Captain Sullenberger performing that amazing feat of landing his aircraft on the Hudson River, a truly remarkable piece of aviating.  The Indian Ocean is not the Husdon River and would rarely be calm enough to offer a perfectly flat surface.  The Boeing 777 has the biggest jet engines around, so they would be wonderful water scoops that would have the effect of ripping the wings off as they filled with forward motion arresting water.  My point is, the chance of the aircraft remaining intact and preventing floating objects from escaping seem to be very remote.

The French island of Reunion. A very remote part of the world.

Today (04 Sep 15) we learn that the French have confirmed that there are enough corresponding serial numbers on the flaperon  found in French ruled Reunion Island to be able to say it is from the doomed Malaysia Airlines Flight 370.   This is confirmation at least that MH 370 is to be found in the Indian Ocean somewhere.  Through reverse analysis of ocean currents and severe weather anomalies over the past 18 months, oceanographers and meteorologists now have a chance to try and pin down more accurately the final rest place of Malaysia Airlines Flight 370.  Perhaps a saving grace is that the piece found was a heavier item that floated blow the water surface.  This means that the ocean currents would be the strongest governing factor in its journey, rather than the more volatile winds it encountered on its way.

We can only hope that with this new information questions can be answered to allow MH370 to be found.  For the sake of the loved ones who need closure.  For aviation itself, no accident or tragic event is ever left unsolved.   Not for curiosity but for fight safety.  Your ability to step onto a plane and give no thought to your chances of stepping off at the other end of the journey is a hard won expectation.  Every event is investigated to the finest detail to ensure these events never happen again.  One day we will know what transpired on MH 370.  One day we will know that those who tragically lost their lives on MH 370 will teach us a lesson that will help us save more lives in the future.

Please feel free to comment or leave your thoughts about MH 370.

Thank you