A McDonnell Douglas DC-10 has been made into a well-equipped eye hospital.


THE FATE OF AN AGEING airliner is usually either to decline towards the scrap yard via a series of increasingly lower level airlines, or to be turned into a freighter. For one McDonnell Douglas (MDC) DC-10, however, fate has been a little kinder: it is being used in the fight against blindness.

According to the World Health Organisation, there are 42 million sightless people in the world, around 70% of them needlessly so. Comparatively simple surgical procedures can restore their sight - but these surgical procedures are not necessarily available to the majority of the world's population. That has been the chief concern of the charity Orbis International since it was established in the USA in 1978. Together with sister organisations in Hong Kong and the UK, the charity began operating a fully equipped hospital aircraft, treating patients in remote and inaccessible parts of the world.

Although surgical operations are carried out on board, the more important purpose of each mission is to educate the host country's own eye specialists in the vital skills necessary to combat blindness. Since it began operations in 1982, Orbis has visited 71 countries, treated 20,000 blind people, and passed on expertise to over 70,000 medical staff worldwide.



The charity's first aircraft was an MDC DC-8-21, donated by United Airlines. After flying it nearly 185,000km (100,000nm), Orbis was forced by rising maintenance costs and the scarcity of spare parts, coupled with increasingly tight noise restrictions to seek a replacement before retiring the aircraft. Donations from several sources allowed the charity to purchase an MDC DC-10-10ER for $13.7 million.

The aircraft was the second of its type to come off the production line and was originally to be part of a 1970 delivery batch to American Airlines. It was retained instead by MDC for development purposes, and was not used for commercial services until 1977, with Laker Airways. After Laker's demise in 1982, the aircraft was flown in Europe with British Caledonian's charter operation, which later became Novair. It was handed to Orbis in 1991.

Despite being 20 years old, the aircraft was considered to be mid-life in terms of airframe hours and landing cycles, having accumulated about 35,000h and 10,000 landings.

Orbis engineers spent more than two years designing and adapting the airframe to meet exacting medical standards. Only the front part of the aircraft retains any semblance of its former commercial usage. The forward cabin is kept and has been equipped with 50 club-type seats for use as transit seating for the volunteer medical staff. On the ground this is used as a classroom/lecture theatre, and the appropriate audio-visual equipment is installed.

Just aft of the forward cabin is a miniature, yet comprehensive, video production suite. The surgical procedures carried out on the aircraft can be transmitted live to the classroom and can be recorded and subsequently edited for use as permanent training material. The floor in this area has been strengthened to support the heavy equipment racks. Behind the video area is a laser treatment room for individual examination and instruction. This area can also be used in the field as a laboratory or classroom.



The operating room occupies much of the area over the wing. This area receives specially filtered air on a circuit separate from the rest of the aircraft. A conference area with large sealed windows allows surgery viewing without contaminating the sterile surgical area. Dual-view teaching microscopes with televison adaptors and other special equipment has been installed. Much of the equipment, was donated to the project by the manufacturers.

Because precise optical and laser equipment had to be installed, some of the floor panels were strengthened to assure a deflection of less that 0.002mm when someone walked near the area. Therefore, the operating theatre could only be located over the strongest part of the airframe - the wing box. This required stress and load design analysis by MDC.

The recovery area immediately aft of the operating room and the final section of the aircraft contains a fully equipped communications centre enabling the crew to communicate by various methods with their home offices in Houston, Texas, and London in the UK.

One benefit of using a wide-body is the provision of a separate passageway along the port side. In the previous aircraft it was impossible to walk from one end of the aircraft to another without violating the sterile operating area. On the lower deck, three cargo containers hold the generators, which provide power and air conditioning while the aircraft is used as a teaching hospital. Only the video suite and the forward cabin are powered in flight. Operating procedures are not normally carried out en route.

The hold area, once emptied of these containers, has been adapted to form a workshop area for the maintenance personnel. A certified mechanic accompanies the aircraft on all its missions, allowing all normal line maintenance to be performed in the field. This is carried out by a mechanic employed by United Airlines -one of the project's major sponsors. The mechanics work with Orbis for 12 months at a time, supported by volunteer assistants.

The flight deck crews are also provided by United. The two pilots and flight engineer on the aircraft's recent visit to Manchester had just retired from line duties and were happy to be involved with a humanitarian mission.

The lower deck galley has also been removed and converted into working space and a library for both medical and airframe purposes.

The DC-10's extended-range 15,000kg fuel tank installed for transatlantic operations is retained in the cargo area and a water- purification system added. The latter is considered essential as local supplies cannot be relied upon. The system is so effective that Orbis officials claim that rainwater collected from the ramp area and contaminated by fuel and hydraulic liquids can be purified to medical standards.

Because the aircraft spends large periods of time on the ground - it is flown only about 20 times a year - the avionics complement is standard and no extra aids have been added - not even a global-positioning-system receiver.

According to John McDonald, UK director of Orbis, this has its advantages. "Replacing a broken flight instrument at an out-of-the way airport is a much easier task if it involves an older, dial-type gauge or indicator."

Operations at such out-of-the way destinations prompted the designers of the Orbis adaptation to include a generous flyaway kit containing spare parts for almost anything that could ground the aircraft if not replaced at once.

When crisis strikes, as occurred in February with an engine failure, the project relies on help from other DC-10 operators. In this instance, the engine was removed and repaired at Prestwick in the UK by Aviall-Caledonian while the aircraft was kept airborne thanks to the loan of an engine from FedEx.

The interior design of the aircraft took nearly 12 months and was based on the experience gained in 12 years of DC-8 operation. The design team included aerospace engineers as well as medical personnel.

While this work was being undertaken, the airframe was given a complete refurbishment including new pneumatic, hydraulic, electrical, air-conditioning and environmental systems. Repainting and corrosion-proofing work was also carried out.



The additional technical equipment added about 47,000kg to the empty aircraft weight, with galleys and toilets and most of the seats removed to compensate. Fully fuelled, the aircraft weighs 202,000 kg, but it can be operated from most airports provided about 2,000m (6,500ft) of runway is available.

The rebuilt aircraft was rolled out of the Mobile Aerospace hangar at Houston in May 1994 and departed immediately on a lengthy tour of the Far East which included several areas of China and the project's first visit to Mongolia.

During 1995 and early 1996 it was flown to several areas of India and then to Albania and several former Soviet Union states before its latest flight to Africa. In 1997, the aircraft will head for Central America before being flown to countries in Eastern Europe and then to China and Myanamar.

Source: Flight International