• Aircraft weight and size

There is significant misunderstanding on why there is such a wide variation in fares between short haul and long haul flights. Aircraft are designed for very specific missions, from short haul to long haul, with flight times varying from about one hour to 18 hours. Short haul aircraft, which may perform eight flights a day, are heavier and thus more costly to operate per passenger because the structure must withstand many landing and takeoffs.

Short haul aircraft tend to be smaller in size at about 180-seats and are thus less efficient than a 500-seat jumbo.

• Basic costs

However, the biggest impact is the basic costs of a flight which often are the same regardless of how far you fly. These include landing charges, security screening charges and many of an airline’s operational costs. Boeing once estimated that over 50% of the costs of an airline ticket was simply having the aircraft sitting on the tarmac waiting for passengers. (See the Cost of a Ticket)

• Fuel cost

Finally the amount of fuel burnt to reach cruising altitude is very high compared to the amount used for the entire flight. For instance, on a four hour flight of a 180-seat jet aircraft up to ¼ of the flight’s fuel is used in the first 20 minutes just getting to cruise altitude.

It sounds incredible but it’s true. A First Class suite on some airlines cost $250,000 each and even the humble economy seat can cost $10,000!

The reason is very simple. The seats must withstand a 16G crash force and remain fixed to floor tracks.

• History

In the 1960s and 1970s aircraft seats had to withstand an 8G crash force but crash investigators found that in many crashes passengers were killed not by the crash itself but by seats that subsequently went flying through the cabin. Regulators toughened up the standards to better protect passengers in case of the incredibly rare event of an air crash.

The new standard of 16G is five times more than your everyday crash dummy.

• Reliability

Early jet engines were unreliable. Initially they had an In Flight Shut Down (IFSD) rate of 0.9 shutdowns per 1,000 engine hours but today’s engines, such as the giant GE90, boast an incredible IFSD rate of 0.001 per 1,000 hours.

• Testing

Part of the reliability comes from the exhaustive and torturous testing to which engines are subjected. The GE90 has been tested to 127,000lbs of thrust or 100,000hp!

Testing of a jet engine takes up to two years and includes one test where 4.5 tons of water a minute is poured into the engine and it must keep running.

After that test ¾ of a ton of hail is fired at the engine in just 30 seconds.

• Flexibility

The extraordinary increase in reliability has had far-reaching effects on aircraft design, airline flexibility and costs, all contributing to a reduction in airfares.

Virtually all early jet-powered aircraft had four jet engines to enable them to cross oceans. The only significant exception was the twin-engine Caravelle designed for short ranges around Europe.

In the 1950s, only four-engine aircraft were allowed by regulators to fly more than 60 minutes away from an airport in case of engine failure. But as the jet engine became incredibly reliable, regulators eased restrictions allowing aircraft to fly more direct and economical routes. Today, a twin-engine aircraft such as the Boeing 777 can fly up to 330 minutes away from an airport.

Aircraft builder Airbus put this type of progress into perspective in the early 1990s when it said that its A330 would have to fly 17,880 years back in time to the beginning of the Ice Age before it suffered loss of power from both engines from independent causes.

Finally, virtually all serious engine problems happen within 15 minutes of takeoff!

• London to Sydney

One example is the London to Sydney route. The downward spiral of the cost is spectacular. In 1945, the return airfare was the equivalent of 130 weeks’ average salary. This was a fortune by anyone’s standards and equivalent today to $204,000 Australian dollars for the average Australian worker.

By 1965 with the widespread introduction of the Douglas DC-8 and Boeing 707, it had dropped to 21 weeks and with the Boeing 747 in the early 1970s that figure reduced to eight weeks.

In 1991, it was equivalent to five weeks’ average salary for an Australian and in 2013 it accounts for just over one week’s average earnings.

If the trend continues, analysts suggest that by 2020 the return airfare from Sydney to London will be just three days’ average earnings.

• Variety of noises

Just after takeoff the most significant noise is the retraction of the undercarriage. Passengers will hear firstly the deployment of the main undercarriage doors and then the undercarriage itself retracting followed by the closing of the doors. If you are lucky enough to be sitting in the very front of a 747 you will also hear the spinning nose wheel as it retracts right under where you are sitting. This is typically followed by a reduction in the aerodynamic wind noise associated with having the undercarriage deployed.

Shorty after the undercarriage is retracted and once the aircraft reaches certain airspeeds the trailing edge flaps and leading edge slats will be gradually retracted. Again once these are fully retracted the aircraft is ‘clean’ and aerodynamic wind noise decreases further.

• Engine cutback

Many airports around the world require what is called noise abatement procedures. So shortly after takeoff, passengers may both sense and hear a rapid reduction in power which can be concerning. Don’t worry… it will almost certainly be the pilots easing power back to reduce the impact of noise on local communities.

• Air Traffic

And at some very busy airports air traffic control may keep your flight at a low altitude and thus at reduced power until you clear the area. So almost certainly your aircraft is fine and the pilots are so busy they may not have the opportunity of telling you what is going on.

• Landings

Like takeoff, there are lots of noises associated with landings. Firstly, however you will have reduced thrust – back to idle – as your flight descends. Then the pilot will start a gradual deployment of the flaps and slats to increase lift while reducing speed. The pilot may also deploy spoilers on the upper surface of the wing to slow the plane and these often cause a noisy buffeting.

• Thrust reversers   

Once the aircraft (jet) touches down pilots will almost always deploy the aircraft’s thrust reverser doors which close behind the engines and deflect the thrust forward to help reduce the aircraft’s speed. This will be associated with an increase in thrust. In turboprop planes, the pilots may alter the pitch of the blades to reduce speed and this can also be quite noisy.

• History

Ever since the days of the Ford Tri-Motor and Douglas DC-3, airliners were designed with one large window for each passenger row so that each window seat was actually located right at the window. This design tenet carried over from Lockheed’s famed Constellation to their turboprop Electra and from Douglas’s DC-7 to their DC-8 jet aircraft.

However Boeing and Convair jets sported additional smaller rectangular windows spaced fairly close together, and most jet aircraft today use that configuration.

• Flexibility

The seat track configuration gives the airlines the ability to configure the passenger cabin to meet rapidly changing demands both for types of seating – first business or economy – and the number of seats.

• Early jet engines

The first jet engines on the Boeing 707 and Douglas DC-8 produced just 13,000lbs of thrust or 20,000hp. The engine intakes were small and an air hostess could barely squeeze in for a publicity photo.

Boeing’s first 747 jumbo had much bigger engines which produced about 45,000lbs of thrust. The most recent model, the 747-8, has engines that produce 66,000lbs of thrust.

• Boeing 777

To power the 777, General Electric opted to build an all new engine the GE90. Initial thrust was 96,000lbs, later increased to 115,000lbs to power the larger and longer ranged 777-300ER and 777-200LR.

The GE90 is in fact as wide as the 737 cabin!

You can often see pilots in the cockpit from the terminal windows perform their pre- or post-flight checklists. You will notice they are often looking up and reaching for switches or knobs located over their heads. Those pilots are working with the ‘overhead panel’ that contains controls for various aircraft operating systems.

• Ease the workload

Those buttons, switches, and knobs are placed there for ease of cockpit workload management, and to be out-of-the-way of the more crucial flight controls, throttle quadrant, and main instrument panel.

• Overhead

Although the specific design and layout of overhead panels vary with each manufacturer and aircraft type, controls located on that panel are generally for pressurization, internal and external lighting, circuit breakers, and electrical systems including aircraft power source (external ground power, onboard auxiliary power unit, or engine generators).

All switches and knobs on the overhead panel are specifically designed with different and distinctive sizes and shapes for ease of operation in an emergency.

• Retread

While the word ‘retread’ may generally have a negative connotation, using retreaded or recapped tires is standard procedure in aviation and is regarded as being the most practical, economical, and safe method for maintaining proper landing gear function.

Some recapped tires will last for up to 100 landings, while others will last for less than that, but maintenance personnel and flight crews continually inspect tires for damage or wear. Additionally, visual ‘wear indicators’ on the tire itself offer ample evidence when a mandatory change is required.

• Variable

The specific number of landings-per-tire is affected by such variable factors as weather, hard landings, cross-wind landings, anti-skid action, and rough or damaged runway surfaces. These can all have an effect on the condition of the rubber surrounding the tire’s core, even creating differences in tire condition from one set of landing gear to another on the same airplane. Yes, modern automobiles may be driven up to 50,000 miles on only one set of tires, but unlike airliners, those tires aren’t constantly being flown into concrete at 200 kilometers per hour!

• Approved

In a fully approved procedure, an aircraft can back away from the gate under its own power under reverse thrust. However, before the jet can move backwards, it must roll forward slightly before the reversers can be deployed, and to move off of the tire’s ‘flat spot’ created when the aircraft sits parked on the ramp for any length of time.

A critical component necessary for this procedure is the ramp agent or ground marshaller. After engines are started with the jet still parked at the gate, the marshaller signals the pilot in command when to move forward, and then using a rotating motion rapidly moving the signaling wands one-over-the-other, indicates exactly when to deploy the reversers and back away from the gate. When the aircraft has safely cleared the ramp area, the reversers are closed, throttles are brought back to idle, and the airliner can then taxi out to the runway. (See What are thrust reversers?)