To many of the pilots who were trained by the UK armed services during the 1950s and 60s, the de Havilland Chipmunk is no more than a basic trainer with a tailwheel. To a team of senior Royal Air Force flyers in 1997, however, it is the vehicle for a 26,000km (14,000nm) route-proving journey across Europe, Russia and North America.

"It may be an old aircraft, but it's rugged and robust, and it's beautiful to fly," says Sqn Ldr Tony Cowan, project leader for Exercise "Northern Venture", explaining why he is untroubled by the thought of flying two "slightly modified" Chipmunks on such an expedition.


Beyond expectations

At the end of the Second World War, when Polish emigre Wsieviod Jakimiuk designed the Chipmunk for de Havilland Canada, no-one would have predicted a service life of over 50 years for what, at the time, was seen as a temporary replacement for the pre-War Tiger Moth bi-plane. Nonetheless, the manufacturer, and other licensed builders around the world, went on to build over 1,200 of the type between 1946 and 1961. It became the UK's primary military trainer during the 1950s, and it is estimated that, between 1949 when the UK Government placed a 740-unit order, and 1996 when it was finally retired, over 2 million service personnel gained their first experience of piloting an aircraft by flying a Chipmunk.

These pilots would probably have thought a six-week, round-the-world expedition beyond the capability of the single-engined, low-wing monoplane, but Cowan is confident. "No worries at all," he says, perhaps tongue-in-cheek.

Based at the RAF's Headquarters for Elementary Flying Training at Cranwell, Lincolnshire, he is preparing to depart on the epic flight from London City Airport on 19 May. "The idea is to fly two Chipmunks simultaneously across Western Europe to Moscow; to follow the Trans-Siberian Railway to the Russian eastern seaboard; across the Bering Straits to Alaska; down through Canada to Toronto and then home across the Northern Atlantic, via Greenland, Iceland and the Faröe Islands," he explains.

The aircraft selected for the flight have been upgraded very little, although Hunting Aviation has fitted an auxiliary fuel tank in the rear-seat position, and a global-positioning-system has been installed by Marshall Aerospace of Cambridge. According to Cowen, the extra 110litre fuel tank is designed to be "the same weight as a person - about 180-200lb [80-90kg] - when full". The total fuel capacity is now 190litres, which has doubled the range of the aircraft to around 925km.

The 110kW (145hp) de Havilland Gipsy Major 8 engine, inverted in the Chipmunk, is notorious for an oil consumption of around 0.85litres/h, which presents a problem when the range is increased. This has been overcome by fitting an alternative oil ring to the engine pistons, reducing oil consumption by half.

The flight is being backed by the UK's Police Aviation Services (PAS), which is supplying a Pilatus Britten-Norman BN2 Islander support aircraft, which will carry spare parts (electrical components, two wheels, one propeller), a first-aid kit, technical documents and charts, and extra fuel and oil. It will be crewed by a PAS pilot, an aircraft engineer from Hunting Aviation and, for the sector east of Moscow, a navigator from the Russian air force.


Tough Russian sector

Cowan believes that the Russian leg will be the most demanding part of the journey, as "-we know so little about the region". He is not sure what to expect in terms of air-traffic control, landing conditions at airfields or accommodation at each location.

"We flew two Chipmunks to Moscow in July 1996, but we were advised by the authorities not to proceed further east because of the excessive heat and the danger of forest fires," he says. This time, because the flight is taking place in June, temperatures will be in the region of 20íC, and forest fires are not expected to be a problem.

After leaving Russia, the route will take in Canada, with a stop at Toronto, home of de Havilland Canada, to celebrate 50 years of the Chipmunk. After calling at the RAF base at Goose Bay in Newfoundland, the aircraft will be flown at a height of 12,000ft across Greenland to Iceland and then back to the UK.

All safety equipment being used is standard RAF issue, including a personal survival pack for each pilot, parachute, life-saving jacket and emersion suit for the over-water sectors.

According to Cowan, the objectives of the exercise are fourfold. "We aim to: establish an air route between Europe and North America without crossing the Atlantic; provide evidence of improved East-West relations; give sponsors (which include the UK telecommunications company BT, British Aerospace and CAE Electronics) an opportunity to gain information about eastern Russia and, finally, to improve knowledge in schools, through publicity, about the RAF," he says.

"A lot will depend on luck," he adds, "but we are well prepared, and it should be fun."

Source: Flight International