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AIRBUS-FREIGHTERS "MADE IN GERMANY"

Year on year the proportion of global goods conveyance accounted for by air freight is growing steadily. Conservative estimates forecast annual increases of six per cent for the next two decades. Freight volume will more than triple, while the civil aircraft capacity needed to transport it world-wide will more than double. Some 3,000 additional cargo aircraft will be required on the one hand to satisfy increasing demand from customers and on the other hand to replace ageing aircraft of all different types. Three-quarters of this demand will be met through conversions of passenger aircraft, which can be obtained relatively cheaply on the second-hand aircraft market.

Freight forwarders that ship goods by air distinguish four capacity classes for these aircraft: up to 30 tonnes, 30-50 tonnes, 50-80 tonnes, and over 80 tonnes. The first group includes aircraft types such as the BAe 146, ATR and in future the A320, the third includes, for example, the Ilyushin Il-76 and the fourth the Boeing 747-400F and Antonov An-124. Especially in the case of the giants, the market is pretty simple as there are not so many initial types of the right size.

On the other hand, the 30-50 tonne class is hotly contested, and it is to this category that the bulk of the aircraft deployed belong. Most of these planes in turn are four-engined narrowbodies such as the Douglas DC-8 or Boeing 707, which have an average age of 28 years or more. Accordingly it is here that the demand for replacement is greatest.

Replacements for these elderly planes come in the form of the DC-10/MD-11, Boeing 757 and the Airbus widebodies. Boeing itself is the largest provider of aircraft conversion services for its own types, to which the 767 is likely to be added in the foreseeable future. However, there is still no technological solution for converting this type, whereas around fifty 757's have already been converted. Other types do not currently figure on the programme, as the aircraft that are suitable are still flying in passenger service.

At Airbus, meanwhile, customers can choose from among three products, the A300B, the A310 and the A300-600. The last of these can also be obtained as a cargo aircraft directly from the manufacturer's plant. The other two types, once they have served out their careers in scheduled services, are candidates for conversion, following which they can then be expected to fly for a number of years more as a freighter.

Customer demand for such aircraft knows no limits. Even the biggest freight forwarders like UPS and Fedex, which operate world-wide fleets, are moving from new cargo aircraft to second-hand. At UPS aircraft are flown for an average of 100 hours per month, at Fedex for 150 hours. That is a lot, but still too little to make it economical to operate brand new cargo planes. By contrast, a passenger aircraft is in use for approximately 400 hours per month.

For this reason the Dresden-based company has specialised in Airbus planes. It used to be partnered with the French company, Sogerma, but a workshare has now been agreed within EADS, its parent company, whereby the French are responsible for servicing already converted aircraft, while complete conversion is carried out in Saxony. However, this includes extensive maintenance work on top, as many of the aircraft supplied have flown several tens of thousands of flying hours and are in need of a major overhaul.

Today, Elbe Flugzeugwerke handles some 60% of the market share in Airbus conversions. The main competition comes from BAE Filton. There, however, the company has developed its own design solutions which include the production of completely new subassemblies and effectively mean upgrading the aircraft. In Dresden, on the other hand, they are proud of the fact that only original parts produced by Airbus Industrie are used. This means that even after conversion the Airbus is still entirely Airbus, with up to one-third of it brand-new.

But the critical factors as far as customers are concerned are - as indeed elsewhere - competence and price. The Dresden aircraft builders may charge a little more than the British, but customers who have the opportunity to compare the two companies, decide more frequently in favour of the Germans. Operational experience with the aircraft shows clearly that products of the Saxon company are more reliable and require fewer repairs.

Moreover, aircraft converted by the EADS subsidiary are approved for operation by Airbus Industrie, whereas the BAE type is not. This gives the Saxons all the more reason to stick to their OEM solution. For all that, the A300-600 will continue to be produced in Toulouse until at least 2010, so that Elbe Flugzeugwerke will retain access to new parts for that period. After that, it is true, the competition can be expected to be stepped up and to revolve around delivery dates and prices, even if in Dresden they are not happy with solutions that do not meet Airbus standard.

Normally the freight forwarder purchases a second-hand passenger aircraft and then arranges with Elbe Flugzeugwerke to have it converted. The forwarder specifies his capacity, range and timescales, and the engineers in Dresden recommend to him the conversion standard that is most appropriate to his needs. However, it is also possible to obtain their recommendation first and only then to purchase the aircraft on the second-hand market.

When the plane arrives, first of all the amount of maintenance work needed on it is assessed. This can vary enormously, depending on the age and maintenance condition of the aircraft. All the old subassemblies are replaced, whether they are still working or not. In some cases the aircraft arrive in Dresden already completely "stripped out", while in other cases all the existing fittings have to be removed.

The cost of the maintenance work varies according to the amount of labour involved, whereas a fixed price is agreed for the conversion, irrespective of the condition of the aircraft. The work itself is carried out using prefabricated kits, so that a A300B4 can be converted to a freighter in two months. The company is shortly to begin converting A300-600's, which is expected to take four months. The aim as regards kit production is six months' supply.

After approximately four weeks spent stripping out the aircraft, i.e. removing all the seats, kitchens, toilets, panelling, heating, ventilation and water supply, the aircraft is transferred to the conversion area. There it is jacked up stress-free, i.e. propped up in such a way that there is no loading on the fuselage so that it cannot be distorted during the work.

If the customer wishes, the engines can also be removed. Sometimes these are then taken to be serviced elsewhere, sometimes they are installed on other aircraft and continue to fly on those planes. To maintain the stress-free condition of the aircraft, a dummy weight has to be suspended on the pylon in place of the engines, so that the aircraft remains in equilibrium.

Now, one by one, holes are cut in the structure, and parts of the stressed-skin fuselage are replaced in the area where the big cargo door will later be located. Inside the plane, the cabin floor is removed and replaced with a new, reinforced floor which can take the load of the freight containers. Around the cargo door this floor is fitted with ball joints enabling containers to be freely rotated and then rolled down the entire length of the cargo bay. This installation is supplemented by numerous fastening elements. The windows are replaced by metal sheets, the skin on the sides has its rivets removed and is replaced by new panels of skin.

After approximately six weeks the aircraft is standing on its own legs again and a further four weeks are required to reinstall the heating, ventilation, lighting etc. If a customer so requests, it is even possible to install seats for the couriers and a small galley. The aircraft is now as good as new and completes a month-long test phase before being handed over to the customer, who concludes the process by carrying out an acceptance flight.

After approximately 30,000 hours of labour the old passenger aircraft has been transformed into a new freighter, with every part guaranteed by the manufacturer. It can now embark on its new career.

From FLUG REVUE 10/2001, page 90