Owner-pilots in two TBM aircraft have traversed Antarctica and overflown the magnetic South Pole in the first stage towards achieving the Polar Diamond Circumnavigator Diploma. Recognised by the Fédération Aéronautique Internationale, the world's governing body for aeronautical and astronautical records and sports, the diploma has only been awarded once before, to PC-12 pilots Jack Long and Josh Marvil.

One of the TBM owner-pilots, Sebastian Diaz from Santiago, Chile, united three generations by flying his TBM 850 with his father, 88-year old Patricio – one of the oldest fully-licensed TBM pilots – and his son, Sebastian Jr., as co-pilots.

The other TBM owner-pilot, Dierk Reuter from Chicago, USA, flew with son Alex in his TBM 930, carrying cameras and an inflight tracking system supported by Iridium GO! satellite connectivity. In-flight photos were posted to Instagram in quasi real-time using Iridium messaging.

The 2,700 nm trip for both aircraft from Santiago, Chile, to 75 degrees south, the latitude required for the diploma, required three stopovers and much preparation, as Antarctica offers some of the most challenging environments for aviators. The temperature there averages -56 degrees celsius, with constant winds.

Both TBMs had to fly over the continent, which is nearly five million sqm in size, largely uninhabited and mostly covered in ice. Central Antarctica presents high ground that rises to more than 8,000 ft, with peak mountains reaching 16,050 ft. Clear blue skies can quickly turn to overcast whiteout conditions.

On 1 January, the two TBM aircraft left Punta Arenas in Chile destined for Teniente Rodolfo Marsh Martin airport on King George Island, just 75 miles off the coast of Antarctica, and the continent's northernmost airport. This airport serves the nearby village of Villa Las Estrellas and Base Presidente Eduardo Frei Montalva, a Chilean Antarctic station, with a 4,232 ft gravel runway.

On 2 January, both TBMs continued to the British Antarctic Survey Sky-Blu base, at 807 nm southwest, and reached the 75 degree south latitude turning point before returning to King George Island's airport. On the way, TBM 930 owner Jim Baum arranged a fly-by of the National Geographic Orion, an ice-class exploration ship.

“We are impressed by the airmanship of such TBM owner-pilots as the Diaz family and Dierk Reuter, who carefully prepared this dual polar expedition,” commented Nicolas Chabbert, senior VP of Daher airplane business unit. “We salute the confidence they have in our TBM very fast turboprop aircraft, as they had to face extreme weather conditions flying over one of the world's most hostile regions.”

Dierk Reuter adds: “The journey from my hometown Chicago to 75S 71W and back can be summarised in figures: 18,782 nm, 64 hours, 3,080 gallons of jet fuel, and 19 stopovers. But it doesn't tell the story about a pilot's feeling to fly over the South Pole. The TBM is an awesome aircraft to explore the globe.”

Diaz says that freezing fuel could have been a problem: “We were dealing with extreme low temperatures, for which we used more Prist, a fuel system icing inhibitor, than usual. We would also like to thank the Chilean Air Force for its generous hospitality at SCRM (Base Presidente Eduardo Frei Montalva).”