Polar 5

Retrofitted into a polar research aircraft

After 65 years of service, transformed from an old timer to a high-tech snowbird

On 1 October 2007, the research aircraft Polar 5 first entered service for the Alfred Wegener Institute. Sporting a fresh coat of paint, the aircraft, now a Basler BT-67, made a youthful impression, even though the “lady” was already over 65 years old.

In 1942 it rolled off the assembly line of the Douglas Aircraft plant in Santa Monica, California as a DC-3T with serial number 19227. More than 15,000 aircraft were manufactured there and as licensed replicas at other sites, and several hundred are still in service worldwide. Historically, these aircraft played an important role: after the end of the Second World War, the United States used them as “raisin bombers” to supply the citizens of Berlin during the Berlin Airlift.

High-tech snowbird

In just eleven months’ time, Polar 5 was transformed from an old timer into a high-tech snowbird. The US-based company Basler Turbo Conversions, which specialises in refitting DC-3 aircraft, began the makeover by extending the hull and installing modern components in the cockpit and propulsion system. Both original engines were replaced with 1281-horsepower turboprop engines. Polar 5 also put on a bit of weight: the new geophysical measuring equipment installed in the cabin and on the plane’s exterior weighs in at 500 kilogrammes.

Purchasing and modifying Polar 5 cost a total of eight million euros, a quarter of which went to the scientific equipment on board. These costs were covered by Germany’s Federal Ministry of Education and Research. Following the refit, the aircraft is now ideally suited for service in the Arctic and Antarctic, and can safely take off and land in the high elevations of the Antarctic Plateau. In addition, the new plane is now considerably larger, allowing to transport more cargo in logistics-centred flights.

Facts and Figures

Name (Registry): Polar 5 (C-GAWI)
Model: Basler BT-67
Manufacturer: Basler Turbo Conversions
Commissioned at AWI: 2007
Length: 20.66 metres
Wingspan: 29 metres
Basic weight:
7.7 t (with ski landing gear 8.3 t)
  Pratt & Whitney PT6A-67R
Output per engine: 1,281 PS
Fuel consumption: 570 litres per hour
Max. take-off weight: 13 t
Max. take-off elevation without payload: 4,200 metres
Range without payload: ca. 3,000 kilometres
Range with 1,000 kg payload: 2,300 kilometres
Max. cruising speed: 
315 kilometres / hour (Indicated Air Speed, IAS) 
Min. cruising speed: 167 kilometres / hour
Crew: 2 pilots, 1 mechanic
Researchers on board for transit flights / measuring flights: 18 / 9