INTERESTING FACTS ABOUT MACHINE TRANSPORTATION BY AIR FREIGHT

 

As there are other variables involved, the freight costs have to be recalculated time and time again. However, one thing is certain: regardless of all other factors, air transportation is practically always the most expensive option of all.

Depending on the conditions, it can cost 20 times as much as sea or land freight. The reasons for this extra price are quickly listed:

• The operating and maintenance costs of all transport-capable aircraft are extremely high in comparison. In the case of a heavy transport helicopter, for example, this amounts to a total of up to 10,000 euros – per hour. Almost half of this is accounted for by the prescribed maintenance work alone.
• Aviation fuel is also often significantly more expensive. As most transport aircraft today are powered by turbines, jet fuels are required. The common mixture Jet A-1, for example, costs over 2.50 euros per liter (including value-added tax and energy tax) – and all aircraft consume a lot of it. Even a very small transport helicopter requires an average of around 40 liters per hour. For a larger fixed-wing aircraft such as the well-known Airbus A320, it is even up to 2,500 liters – exactly how much depends, among other things, on the total weight of the aircraft and the performance of its engines.
• Compared to other forms of transportation, space in or under aircraft is very limited – as is the weight. Even one of the largest and most powerful aircraft in the world in this respect, the Antonov AN-225 (the only airworthy example was destroyed in the Ukraine war), “only” managed 253 tons on one record flight and 42.1 meters of cargo on another. However, the values for more common aircraft are significantly lower. As a result, the possible loads are quite limited, which increases the price per transport.

In view of this, the question now arises: Are there any reasons at all to transport machines in particular as air freight? There certainly are. In fact, despite its high costs, air transportation can sometimes be the most economical option – and in other cases the only possible option at all. This is due to some of the realities of air transportation:

• Speed:
  Apart from prescribed flight corridors, aircraft can always take the literal “air route”, i.e. the direct route. This is always the shortest and therefore fastest route. Depending on the aircraft, there is also a fundamentally high speed. A helicopter with internal cargo, for example, can reach speeds of between 200 and 300 km/h, depending on the model. The cruising speed of a jet-powered transport aircraft is even between 800 and 900 km/h. This makes air freight an ideal choice when it comes to the maximum time-critical relocation of machines.
• Accessibility:
  It is by no means economical or even possible to transport all freight to its final destination by land. For example, because roads, if there are any at all, are not sufficiently dimensioned for the transport vehicle or are too steep. A typical 40-ton truck, for example, has a length of around 18 meters and can only manage gradients of 30 percent at most. A helicopter, on the other hand, can move a load regardless of the distance. In the high mountains, for example, it is the only alternative to the much more expensive expansion of a road or cable car infrastructure.

This means that air transportation of machines should always be considered if

• it has to happen as quickly as possible,
• very large land distances have to be bridged and/or
• there is little or no accessibility by land or water.

Incidentally, the latter need not only be the case in the high mountains. For example, in a triangle between the Russian North Pole island of Novaya Zemlya, the Himalayas and the North Pacific, there is an area of several thousand square kilometers that cannot be reached by river or (all year round) by land – at least not economically.

The same applies in the vast expanses of Canada away from the coasts and in many parts of South America and sub-Saharan Africa. Here, air transportation of machines may actually be the only sensible choice.

AIR TRANSPORT: THE POSSIBLE AIRCRAFT, THE TYPES OF TRANSPORT AND THEIR PERFORMANCE DATA

As already mentioned, there are basically two common methods of transporting freight by air. Fixed-wing aircraft, i.e. conventional airplanes, and rotary-wing aircraft, better known as helicopters.

An important piece of information: there is neither “the” airplane nor “the helicopter”. Within both groups, there are hundreds of different models with equally different performance parameters in use today. A very light, highly specialized crane helicopter such as the Kaman K-Max can move a sling load of around 2.7 tons. A heavy transport helicopter such as the Boeing CH-47F, on the other hand, has a load weight of around 12.5 tons.

Therefore, an explanation of the typical types of transportation and the common upper limits is provided here:

Fixed-wing aircraft

Mainly for aerodynamic reasons, transportation takes place almost exclusively in the fuselage. Only a tiny minority of very special transport aircraft are capable of moving loads on their backs or have particularly large cargo holds that are constructed almost like a back container. One of the very few commercially possible (i.e. charterable) aircraft of this type is the Beluga series from Airbus.

In principle, the cargo here is limited both in terms of its dimensions and its weight. In the Beluga ST model, the cargo hold measures 7.1 m high, 6.7 m wide and 39 meters long and can hold 47 tons of mass. At 1,400 cubic meters, this is one of the largest flying cargo holds ever. It is only surpassed by the Beluga XL model, which has 2,200 cubic meters with a length of 46.6 meters and a cargo weight of over 50 tons.

However, the dimensions of most other transport aircraft are much more limited. However, the cargo weights are sometimes much higher. Some types currently in commercial use:

• Antonov AN-124: 150 t
• Boeing 747-400LCF: 150 t
• Boeing 747-8F: 137 tons
• Antonov AN-22: 88 t
• Airbus Beluga XL: 50 t

In addition to these models, there are also powerful military transport aircraft. For example, the Lockheed C-5, which can transport 122 tons. However, these are generally not available for commercial transportation.

In fact, the performance data mentioned is currently the absolute maximum for air freight transportation. If a machine cannot be brought down to a maximum weight of 150 tons or cannot be dismantled to suitable loading space dimensions, air transport is simply out of the question.

Important: The larger and heavier the aircraft, the fewer airports are suitable to accommodate it. This applies in particular to the length of runways. The Boeing 747-8F mentioned above, for example, requires over 3,000 meters of runway at sea level at maximum take-off weight. At higher altitudes and/or at high temperatures, such values can increase considerably. The same applies to the landing distance.

For the medium and distant future, experts have been discussing the return of large rigid airships, which quickly went out of fashion after the crash of the Hindenburg in 1937. They are talking about carrying masses of 50 tons and more – although the differences in manoeuvrability and flight principles would be blurred:

Rotorcraft

Unlike airplanes, helicopters (except at very high altitudes) do not have to be kept at a certain minimum speed in order to generate sufficient lift. This speed is ensured by the spinning rotor. As a result, helicopters are known to be able to take off and land vertically and hover on the spot.

For this reason, the transportation options with these aircraft are different. Among other things, this means that helicopters can move loads whose dimensions significantly exceed those of their cargo hold. In this case, the load hangs below the aircraft, in a similar way to a ground-based crane.

This option enables very special transports that cannot be realized with any other technique. However, this comes at a price: flying with a hook load is one of the most demanding tasks of all. This is because the load has a very strong effect due to its inertia, for example by resonating during braking. Depending on its shape, it can also have a significant impact on aerodynamics. Just how difficult the work is can be seen in the DGVU Information 214-911 “Safe use of helicopters for aerial work”.

As a result, flight distances are fairly limited, especially for external load transport – for many models to a few dozen to a few hundred kilometers. Depending on the model, the maximum dimensions of the loads are similarly limited to those of transport aircraft. However, the weights of the commercially available models are lower (data refers to external loads):

• Mil Mi-26: 20.0 t
• Sikorsky S-64: 8.0 t
• Kamow KA-32: 5.0 t
• Mil Mi-17: 4.5 t
• Mil Mi-8: 3.0 t
• Kaman K-Max: 2.7 t
• PZL W-3 1.8 t
• Bell 212: 1.5 t

Helicopters that transport external loads also have a very complex personnel “infrastructure”. For example, special instructors are required on board and/or on the ground. In commercial charter or rental operations, billing is often based on minutes.

Important: Due to the decreasing air density with increasing altitude, the maximum altitude at which a helicopter can safely hover with a load is usually lower than its maximum flight altitude. Depending on the model, the value is up to around 4,500 meters – also depending on the outside temperatures. The hotter, the lower.

Incidentally, it should also be noted at this point how much this topic is currently undergoing a radical change due to the development of very large drones. The aforementioned Kaman K-Max, for example, already exists in an unmanned version. As drone control technology is largely independent of size and carrying capacity, a lot is likely to happen here in the coming years.

AIR TRANSPORT IN PRACTICE

Due to the time required or the location of the pick-up or delivery point, a company comes to the conclusion that transportation by plane or helicopter is the only suitable method for relocating a machine. In this case, many things are surprisingly similar to more conventional transportation by road, rail, inland waterways or the high seas:

1. It all starts with choosing a suitable transport company. In this case, an air freight company. If air transport is only one part of a larger transportation undertaking, there is also the option of having this part carried out by one of the other transport service providers.
2. The machine is made suitable for air transportation: everything that could be problematic at high altitudes (air pressure) is lowered or otherwise secured. Sometimes the machine is partially dismantled in order to achieve a suitable weight or dimensions.
3. The next step is to prepare the air freight for transportation itself. This means, for example, loading it onto special pallets that are fitted with suitable lifting or lashing points. Load securing is always important, but it is vital for air transportation. Loose cargo has already led to numerous plane crashes due to the shift in the center of gravity.
4. In the case of transportation by plane, it is now necessary to transport the machine to the nearest suitable airport. If the transport is carried out by helicopter, however, it may be sufficient to bring the prepared load to a large open area on the company premises, depending on the situation.

Once the transport is complete and any customs formalities have been completed, further transportation services are naturally required for aircraft. With appropriate weights and dimensions, it can therefore even be an economical option to transport a machine by both helicopter and airplane.

However, one thing is practically always certain: if it is an air transport, then all other options are not feasible for a variety of reasons, despite a perhaps significantly lower price – even if it is only because the aircraft has to be available on the other side of the world two days later at the most.

Image sources:

1. adobe.com © Alex J
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6. adobe.com © Phuong