Antarctica’s unique environment throws strong winds, fog, drifting snow and many other challenges at pilots working for the British Antarctic Survey | Words: Robin Evans – Photos: BAS

About twice the size of Australia, Antarctica is the largest, highest and coldest wilderness on earth. Covered in ice millions of years old, up to several kilometres thick, it rises onto a polar plateau ten thousand feet high.

Mountainous belts, peaking at Mt Vinson’s 16,050ft, punch through this. The interior is alive with crevasses and glaciers grinding towards the coast, and these in turn are hugged by vast, floating ice shelves, now showing increasing signs of instability.

As glaciers retreat and ice separates, topographic surveys are constantly updated, often from the original surveys of the 1960s. In 2017, Mount Hope was reclassified as the highest point in British Antarctic Survey territory at 10,654ft?satellite data revealed it had been underestimated by almost 1,000 feet.

Flying over the Antarctic surface is a bit like skimming over cloud at speed?all white valleys and peaks stretching forever?but it’s hard not soft. There’s even a word for the undulating forms, sastrugi.

“They’re wind-blown lumps like sand dunes, set like concrete,” explains Rod Arnold, Head of Air Operations at BAS. Originally a biologist, Arnold has experienced fifteen Antarctic seasons, which has proved useful in his subsequent role managing a team of twenty, half of them pilots.

His tenure has seen BAS’s scope broadened beyond the polar regions, and the award of the Honourable Company of Air Pilots’ Johnston Trophy in 2017 for outstanding airborne performance. BAS’s headquarters outside Cambridge is part cutting-edge science hub, part a reminder of British contributions to a remarkable history at the end of the earth.

Pilots can expect around 400 hours and thirty weeks of annual deployment. Duties include all aspects of aircraft operation, including loading, cleaning and refuelling. Pilots must have a CPL/IR or ATPL, with 2,500 hours minimum. A Twin Otter rating, ski time or other specific flying experience is not required.

“The background of our pilots is very well spread,” says Arnold about the diversity of his team, “but we do look for a thread of single-pilot ops within that.” BAS provides survival training, groundschool refreshers and simulator training. “The simulator adds many useful techniques: whiteout landings and overweight performance, for example, to give us a huge level of preparedness.”

British Antarctic Territory is wedge-shaped, radiating from the South Pole to 60?S, between longitudes 20-80?W. It centres on the Antarctic Peninsula, the closest point to South America, giving an overlap with Argentine and Chilean territory, also including The Falklands.

Many nations make territorial claims, but these were placed in abeyance by the 1959 Antarctic Treaty, which binds all together in scientific coexistence. Arnold summarises: “in this sort of environment, we don’t turn our backs on each other, it’s about getting the job done.”

The international scientific community peaks at around 5,000 during the Antarctic summer between October and March, after which most people depart, leaving hardy, overwintering personnel.

Whilst early exploration (see ‘A history…’,) focused on the most obvious facets, Antarctica now hosts profound research into its depths. “Antarctica holds the key to unlocking secrets of our past, as well as helping predict the future,” says Arnold. He highlights its unique scientific draw: geophysics, climate science, oceanography, geology and astronomy?all dependent upon air support.

The largest British Antarctic facility?and the Air Operations hub?is Rothera Research Station, founded in 1974-5, on the western coast of the Antarctic Peninsula. Permanently occupied, Rothera has evolved organically and is currently being modernised.

“Together with the commissioning of the soon-to-be-launched RRS Sir David Attenborough, this represents the largest Government investment in polar science infrastructure since the 1980s” reveals Arnold.

Construction of a new wharf at Rothera is underway to accommodate the new vessel, which will replace two existing BAS ships, displacing some logistical support back onto the Air Operations team.

The 900 metre gravel runway at Rothera serves as a gateway into Antarctica. Arnold explains, “We spray it with seawater and the salt crystals help bind it together, an established Canadian technique.” The primary threats here are strong winds, blowing snow or fog-inducing warmer air rising off the sea.

“At Rothera there’s nothing upwind of us. No marine services or automated buoys, so the forecaster is dependent on models and validation by satellite images, as well as observations sent in regularly from field camps?all field personnel are trained in met observation. We do get storms tracking through, particularly around the shoulder seasons that pump snow onto us.”

At the Antarctic Peninsula base, 900km south of Rothera, lies the 1,200m blue ice runway of Sky-Blu, elevation 4,700 feet. “It’s a natural feature, but anywhere blue ice is encountered you know it’s windy, as the snow is continually scoured off the surface,” continues Arnold.

“Sky-Blu used to be considered deep-field but is now the geographic centre of our field operations; the aircraft have really helped us open up the interior.” A network of unmanned depots and temporary camps with names such as FD83 (Fuel Depot 83?S) stretches beyond the Pole.

BAS serves this Europe-sized area with four Twin Otters and one Dash-7 to complement land-based convoys. Sorties into the continent are flight-planned, particularly as the traffic funnels into corridors, all nations using common VHF/HF frequencies. “It’s a small enough team for us to always know where our assets are. We know from hundreds of kilometres out that someone’s coming: they’ll want the forecasts from us and vice versa.”

In 2018, the Twin Otter achieved the milestone of fifty years of BAS operations. The Falklands-registered workhorses are the backbone of operations, carrying personnel, supplies or scientific equipment. A proven asset and plenty of time spent camping on the ice inspired its affectionate nickname, the Twinnebago.

The Dash regularly operates to Stanley in the Falklands or Punta Arenas, Chile. This requires special procedures: flights may turn back at point-of-no-return (PNR) if conditions deteriorate. Departure and destination weather reports are mandatory until a flight commits, the Rothera runway kept sterile once the Dash passes PNR.

Meanwhile, the Twin Otters are the mainstay of deep-field delivery and science, flown single-pilot with a second crewmember. “It’s really motivating for station staff and the independent check of a colleague is invaluable,” says Arnold.

Operations must be totally independent, supplies ferried in and all waste removed. Fuel is the lifeblood of the Antarctic, airlifted throughout the network. “It’s a pyramid of fuel, something that critically limits our logistics,” explains Arnold.

The Dash is particularly useful here, freeing up the Twin Otters to work elsewhere. “It takes seven hours flying and six drums of fuel in a Twin Otter to deliver four drums onwards to Sky-Blu; the Dash-7 can drop sixteen drums twice a day.”

The embedded value of fuel increases the further it is ferried. While cash does not change hands between nations, six fuel drums at Rothera might be worth two at a remote field location, the same for team member berths or spares.

Arnold reveals: “We couldn’t support our programme without that quid pro quo with other operators under the auspices of the Antarctic Treaty.” He notes an encouraging development, “The RAF has recently started airdropping fuel?a massive short-circuit of our distribution planning to facilitate remote science.”

All structures soon disappear under fresh snow. Fuel deposits are marked by empty barrels on long poles. “The barrel acts as a visual marker and will appear on weather radar. We spend a lot of time finding and then digging up our fuel!” There’s also a more insidious force?the ice streams that drain the continent.

“Our fuel is often not quite where we left it. One party found their camp to be moving at two metres a day.” In marginal conditions, this could be critical. Scott’s 1911-12 polar mission poignantly illustrates this. He, Wilson and Bowers died of exposure in a tent on the Ross Ice Shelf where they still lie, slowly compressing downwards into the ice, migrating towards the coast. In many decades they will return to the sea inside a calving iceberg.

“The work pattern and time zone are dictated by where the operational support is based, initially our forecaster at Rothera,” explains Arnold. “If based out of McMurdo (the US Station on the Ross Ice Shelf) or the Pole, we would switch to their time zone and operational support, particularly as their forecasts would be issued in their time zone.” As fieldwork is weather dependent, teams are permitted the flexibility to manage their workload.

During continuous midsummer daylight, work might continue around the clock. Working patterns might also be shifted for optimum temperature, varying from 0?C at Rothera to -30°C on the plateau, and colder at the Pole. “You can go from working at Sky-Blu in full Antarctic gear to barely sub-zero in the north,” reveals Arnold.

The pilot’s view

Vicky Auld has experienced five Antarctic flying seasons, benefitting from her previous role as a BAS meteorologist. “I originally joined BAS because I was keen to continue climate change studies,” she recalls.

She was one of a dozen overwintering specialists working at Halley Station, a modular laboratory on the Brunt Ice Shelf, currently occupied only in summer due to ice instability. Her experiences of the Twin Otter buddy system had a surprising effect. “Flying wasn’t on my radar until one too many co-pilot flights.”

This prompted a career change and initial time on the Dash 8-Q400 in the UK before rejoining BAS. “I came in with relatively low hours compared to the experience of some of our new recruits, but plenty of Antarctic field experience, the part that is unknown for most. I feel I am still supporting an area of science that is important to me.

“To move into single-pilot command of the Twin Otter in the Antarctic environment was a huge challenge,” says Auld. “In the field everything requires judgement, rather than working to the very specific limits of the commercial world. The personal limits you might set for yourself then change as you recognise your judgement and ability improve with experience.” She describes how different disciplines combine in practice.

“It’s a fascinating process getting to understand what the scientists want, and how we can best achieve it. Our scientists are often pleasantly surprised to find out how interested all the staff are in their projects.”


A history of heroic exploration

Exploration by sea, land and finally air progressively revealed Antarctica’s mysteries. Cook’s 18th century expeditions proved there was no dominant landmass of the Southern Hemisphere, but there was a mysterious source of drifting ice preventing further discovery.

The Heroic Era (1897¬1922) associated with Amundsen, Shackleton and Scott pushed inland, pioneering brutal survival and the roots of scientific study.

A notable figure of the subsequent Mechanical Age was US naval officer and pilot Richard E Byrd. He led multiple expeditions with aircraft between 1928 and 1956, making the first South Pole overflights and landings.

BAS’s origins go back to Operation Tabarin, a secret World War Two mission that established Port Lockroy, the first permanent British base on Antarctica.


Depending on prior experience, it typically takes three seasons for new pilots to complete all aspects of training. The first season covers basic ski work and navigation, including the first Antarctic solo. “No doubt a trip to Fossil Bluff, a small fuel depot about 1hr 40min south of Rothera” says Vicky, who still considers the route a favourite.

“On a good day we fly past icebergs, seals, whales, glaciers, snowy peaks and stunning meltpools. Magical days, especially when you share it with a person for whom it’s the first time sat up front.” Exposure to deep-field work might come via five- to ten-day trips with either a line trainer or buddying with experienced colleagues.

The second year builds in operational diversity: science surveys, low level and mountain flying. The third season introduces the most challenging sites, “including those that have never been landed at before, within mountains, or on crevassed glaciers that test your decision making to the limit” she explains.

“Some flights involve larger field camps on flat ice sheets, where vehicles have often groomed smooth skiways for us. There seems a disproportionate number of times when the wind isn’t blowing down the skiway, so sometimes the decision to land off-strip into wind is safer than taking a strong crosswind on skis.”

She describes the assessment of unprepared surfaces, first studying satellite pictures and maps of ice movement, then waiting for a day of suitable contrast conditions. Pilots will ‘trail’ skis over the surface to assess how much snow cover there is. “This dictates if we will choose to land on wheels or skis.”

The process is similar to site selection for PPL forced landings: obstacles, surface, slope, slots and sastrugi.

“We fly over and around the intended site, often from different directions to get sun angles that give the best surface contrast before you’re happy to trail. We then fly back at low level over our trails looking for any crevasses or slots that might have opened up. With ski landings, we choose sites where we can trail skis for an appropriate distance so that we can land, stop and take off again in our tracks.”

These techniques quickly become ingrained. “Lots of differential power to assist the nosewheel when steering on the snow, and on landing, in the absence of brakes, plenty of reverse thrust. Always protect the nosewheel as surfaces can be very rough with large, hard sastrugi,” she cautions.

“Yoke fully back for takeoff and immediately on touchdown. The Twinnebago is a very forgiving aircraft to fly. Her double slotted ailerons work in unison with the flaps and the wide beta [propeller pitch] range gives excellent STOL performance.” There’s another, unexpected skill. “Being good with a shovel is essential! You will spend hours digging out fuel drums, science instruments, tents and skidoos.”

BAS aircraft are red for visibility against the ‘flat white’; upper surfaces black for thermal benefits in the absence of de-icing. Some operators use full skis without wheels. Auld describes BAS wheel-skis. “We use the hydraulics to move the skis up and down around the wheel, with a bucket that slides under.”

A recent G950 cockpit update was staggered across seasons to confirm it could withstand extreme temperatures. Internal modifications allow rôle flexibility: cargo (double doors and a strengthened floor) and science (underfloor camera bay, deploying dropsondes or laser scanning).


Home to Canada for maintenance

BAS aircraft depart in March to Rocky Mountain Aircraft of Calgary for annual maintenance ¬ an 8,000nm voyage along the Pacific Coast.

Arnold explains: “Nine days and fifty hours with a day off somewhere in South America; it takes three days just to get through Chile.” The journey incorporates more science, part of a drive to use aircraft efficiently and support non¬polar science.

Arnold highlights a recent study: “We returned via Ontario for a project on forest fires, arranging our flight to coincide with a calibration pass of a European Space Agency satellite. Our science is becoming much more international, not exclusively polar¬focused.”

Recent deployments have focused on the Alps (avalanche risk), Valencia (crop health) and the North Sea (gas sampling). Pilots rotate between projects according to specialism, not always working an Antarctic summer.

“We’re more flexible than we used to be. If you’ve worked a (European) summer campaign, you would get an (Antarctic) shoulder off or a mid¬season break.”


Two aircraft are further modified. One is rigged for airborne geophysics to sense gravitational and magnetic fields. Lasers measure the ice surface, whilst ground-penetrating radar senses the earth beneath.

This allows scientists to visualise the continent without its icy jacket. Concealed beneath are mountains, plains and rivers. Modelling ice volumes enables predictions of world sea-level rise?evidence suggests this would be 58m if all polar ice were to melt. The BAS fleet has flown a total of 593,000km of geophysical surveys.

The second modified aircraft holds Meteorological Airborne Science INstrumentation (MASIN). A nose-mounted turbulence probe and wing hard points supply various instruments for sampling water vapour, trace aerosols and condensation nuclei.

Unlike ground or space-based methods, only aircraft put scientists inside their medium of interest. Vicky adds: “With an atmospheric science background, I particularly enjoy atmospheric survey work, investigating cloud structures, air chemistry and pollution measurements.”

External navigation systems are minimal. Rothera has an NDB/DME and a GPS approach, navigation is otherwise nominally VFR. Charts display a web of radials annotated with distance/time/fuel data. Current penguin colonies are marked to avoid overflight, plus reporting points, automated weather stations, fuel depots, and runways are depicted as blue ice, gravel or groomed snow.

Magnetic variation ranges between 20-40°. Vicky explains, ‘We work in magnetic in our normal operating area, then move to true for some areas of operations towards the magnetic pole and in grid when visiting other bases or close to the Pole.”

The biggest daily threat is the weather: BAS has Met Office forecasters based at Rothera to cover an operating area the size of Europe. “They are extremely competent and often arrive with prior Antarctic experience, but,” she cautions “they are analysing output from models that have very limited input data for our area of the world, which means any forecast is likely to be less reliable.”

This means the daily fly/no-fly decision making process can be demanding. “Often when the decision is to wait and see for another four hours you can feel drained before you’ve got airborne.” This is where the fatigue management plan encourages self-awareness where marginal conditions, area unfamiliarity, and fatigue levels may influence decisions. Reassuringly “our Flight Ops Managers always support individual decisions not to fly even if flight duty period would allow it.”

‘Laying up’ is another skill required of pilots. A temporary home in a traditional cotton tent with a primus stove and paraffin lamp: BAS sticks to proven methods. Meals might be dehydrated ration packs or frozen-down from the nearest base kitchen.

“We always have enough food, shelter and fuel for a minimum of seven days for each person” says Vicky. “If more than three people are aboard we take an extra tent, pots box and food box.” The aircraft carry two HF radios and two satellite phones (one of which can be detached from the aircraft) with extra batteries and a portable solar charger.

Even these rugged aircraft may need protecting, depending on temperatures and what facilities are available. “If we’re in the Arctic or at the South Pole we often have access to power” she continues. Crews use Tannis heaters (electric pads shielding the batteries and engine oil areas) and engine nacelle blankets. “A Twin Otter cold-soaked down to -35°C will start without any overnight protection.”

Full engineering cover is maintained at Rothera. In the field, BAS operates under a Minimum Equipment List that allows a pragmatic approach to technical issues. Aircraft might dispatch with some IFR navigation kit unserviceable if conditions are confirmed to remain VFR for instance. “We are always able to call engineers to discuss problems in the field,” she adds.

When asked what she would never get into an aircraft without, her response is practical. “One duvet jacket, two pairs of sunglasses, and at least three pairs of gloves.” She summarises her experiences, “Antarctica can be magical but always expect the curveball.

Rod Arnold sums up: “I think people imagine us as eco-warriors. We’re working with some of the world’s leading scientific authorities. They provide the data for policy makers to use in future planning. Many of the statements in the internationally recognised Intergovernmental Panel on Climate Change (IPCC) reports are underpinned by BAS research.

We’re responsible for logistics, but immersed in a science organisation. The science might want a new instrument flown next season. It’s not just the scientist’s problem to worry about how to do that – it’s ours and that’s the empowering thing. It stops becoming about the mountains and icebergs, amazing though they are. We do it for the mission and the team we’re working with.”

The ultimate testament to the skill of the pilots comes from their internal customers. A note from a scientist’s blog observes: “The only pilot I’ve taken my tent down for in the field before the aircraft landed: the highest compliment I could pay an Antarctic pilot.”

It’s a reminder that BAS deals in fundamental survival, both short-term for their personnel and long-term for all of us.

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