AIR TRANSPORT Antarctic air links

Frozen flight

Air links are an essential part of supporting scientific and, increasingly tourism in the Antarctic. ALAN DRON looks at the operators flying in the South Pole and plans to enhance airfield infrastructure.

RNZAF Boeing 757-200 in Antarctica. NZ Defence Force

For aircrew accustomed to the closely controlled conditions of European or North American airspace, flying into Antarctica is a very different experience. No air traffic control, few navigational aids and runways composed of sheet ice or compacted snow.

Not your normal day at the controls

However, flights into the white wilderness are more common than one might think. Increasingly in recent years, large commercial aircraft have operated below 60 degrees south, mainly to provide personnel rotation and supplies for scientific outposts.

Cape Town is the jumping-off point for many such flights. Some idea of the distances involved can be gained from the fact that it is a four-hour journey south to the edge of Antarctica and typically another hour to reach the appointed landing strip.

These services entail strict operating conditions. Boeing 767s, which have been used by several carriers for Antarctic flights, have sufficient fuel capacity to undertake a return trip from Cape Town. The smaller Boeing 757, also used by several operators, does not, and would be in difficulty if it got as far as Antarctica, only to learn of a problem with the ice runway.

This necessitates calculating a go/no-go point on the outbound leg, a factor that came into play on one service operated by UK-based charter specialist Titan Airways. It was told only shortly before departure (for security reasons) from Cape Town that an unexpected VIP group, including former US Vice-President Al Gore, now an environmentalist, would be joining the flight. “On this occasion, the weather was not as favourable as previous visits but was sufficient to meet our required departure criteria,” recalled Titan’s Flight Operations Director Joe Dennett, one of the pilots involved.

However, en route, conditions in Antarctica started to deteriorate. Fast approaching the predetermined decision point, news of poor weather and high winds made landing there potentially dangerous: “We had to make the decision to turn back and land in Cape Town.”

Titan has made several trips on behalf of Cape Town-based Antarctic Logistics Centre International (ALCI) and some of the Russian research stations on the continent. Supplies are airlifted to a central point, then distributed by smaller aircraft to bases around Antarctica. Typical loads include food, bedding, medical supplies and vehicle spare parts.

Considerable planning precedes such trips. “Risk assessment was quite extensive and had to take a number of things into account, including fire and rescue capabilities, ability of the aircraft to sit on the ground in sub-zero temperatures and crew welfare, including safety and survival training,” said Dennett.

Titan had access to specialist weather forecasting, including meteorologists in Antarctica itself. “We planned our flights around known seasonal weather windows, supplemented by various weather briefings that started T-5 days before our planned flights, even before we left the UK for Cape Town.”

Weather watch

A major factor was understanding how quickly the weather in Antarctica could change, said Dennett. “To mitigate these risks, we took Arctic survival experts with us. They had ultimate control once we arrived on the ground, if conditions took a turn for the worse.”

Minimal ground equipment at the Antarctic airfields meant there was no capability to de-ice wings and airframe in the event of a sudden snowfall, which would have necessitated a rapid departure if the weather was forecast to suddenly close in.

Titan engaged a specialist consultant with Antarctic flying experience and created a simulator training package prior to its trips. Simulator databases do not include Antarctic strips, so the team used an airport simulation with flat, featureless terrain that resembled the Russian strip at Station Novo (Novolazarevskaya) as closely as possible and set the simulator’s criteria to mimic icy surface conditions.

An ice runway is not as difficult a landing surface as one might initially think. Loftleidir, Icelandair’s charter arm, has operated a 767 into Antarctica on several occasions in recent years. Last February, it flew into Troll Station, operated by the Norwegian Polar Institute in Dronning Maud Land, some 250km inland from the continent’s edge.

“The Norwegians have built a runway on the blue ice that is special because of its strength and structural nature,” co-pilot Bjartmar Örn Arnarson noted in his logbook. “It has been beaten down with constant hurricane-force wind that has squeezed the air bubbles out of the ice and it appears deep blue. Because of its solidness it can hold a massive airplane like the Boeing 767 and is really smooth.”

The biggest problem, ironically, occurs if temperatures start to rise. “The physical properties of ice start to change when it gets above –5C,” explained Sven Lidström, who is responsible for Antarctic operations at the Norwegian Polar Institute. Blue ice, being darker than snow, will attract the sun’s rays and melting will accelerate. “When it’s cold, it’s not a problem to take a big aircraft down there but, when it gets warmer, the aircraft is going to land on water, not ice.

“What we do is we cover the runway up with snow…if we cover it with 10cm or more of snow, it insulates it quite well.”

Leisure flying to the frozen continent is also increasing. “There’s been a dramatic rise in aircraft flying in, in the last couple of years, mostly due to various companies flying in tourists.”

Aircraft flying into Troll Station use their own navigational systems, although there is a GPS approach. As noted above, weather is a challenge and around 50% of flights have to be moved by a day or two to utilise short weather windows.

On the military side, the US Air Force flies into scientific camps with Lockheed Martin C-130 Hercules equipped with dual ski/wheel undercarriages, while the Royal Australian Air Force has undertaken several programmes of flights since 2015 with its Boeing C-17 Globemasters.

Flying on Ice

What’s it like flying into Antarctica? Flt Lt Flynn Cribb, a Boeing 757 co-pilot with 40 Sqdn, Royal New Zealand Air Force, shares some insights.

The focus of simulator training prior to landing in Antarctica is to train for a white-out landing scenario, should weather deteriorate after our point of safe return (PSR). This involves practising the techniques required to land without visual reference on an ice runway. This is obviously not an ideal scenario and we do everything we can to avoid getting into this situation but it is still a risk we carry on every flight.

We operate out of Christchurch with a flight time of around 4:45 hours. We generally hold Dunedin as an en route alternative on the flight south and calculate a PSR to return to Dunedin. This means should the weather, lighting, communications etc deteriorate prior to reaching this point, we can return to New Zealand with reserves intact. Beyond this point, we are committed to arriving in Antarctica. PSR is normally around 3:30 into the flight, leaving just over an hour’s flight time before touchdown. There are no suitable alternatives in Antarctica so, should weather or fog generate over the airfield, it remains the only suitable landing option. We are keenly aware of the weather on the day. There are some key indicators related to wind and pressure systems that we keep an eye out for prior to launching. We also always carry an additional two hours holding fuel on top of normal reserves, so can hold / make multiple approaches if required.

How does a 757 handle on snow?

There is not really a major difference in how the aircraft handles. We use NZFX (Phoenix Field) for our current operations. It’s 10,000ft of compacted snow that is well cared for by the team based in Antarctica.

We have a minimum runway condition reading (RCR) that we operate to, which is provided daily prior to a GO decision. This roughly translates to a minimum friction value and a maximum snow depth to ensure braking is suitable. This RCR can deteriorate following recent snow, or excessive sun. The team based down there use a lot of heavy equipment, similar to that used on ski fields, to groom the runway. They do this between every departure and arrival, so we generally try to minimise our use of the runway (for example, using a higher flap setting for take-off to minimise roll distance).

There is a greater tendency for the aircraft to slip or skid during taxiing – but this is easily mitigated by using slower than normal taxi speeds. The touchdown is generally soft, certainly more forgiving than the pavement we are used to. We also reduce our crosswind limit significantly, to maintain a good margin on directional control at touchdown.

The extremely cold temperatures down there, around –40C are generally too cold for significant ice formation on the aircraft structure but we always check during flight, after landing and before departure.

The most notable difference when flying down there is the lack of visual cues. On a perfectly clear day, depth perception is generally good and all perceptible parts of the airfield are easily identifiable early on the approach. It is much more difficult to judge height and distance during approach when you have a cloud layer a few thousand feet above the field. The surface can blend into the cloud layer, making the horizon imperceptible. During these overcast conditions it requires some preparation to know what the edge markings, centreline flags during approach and lighting looks like. If you know where the runway is supposed to be in relation to easily identifiable features, like the vehicles and structures associated with the strip, then you are much better placed to identify the runway and touchdown zone early on.

Surface and horizon definition is reported to us prior to making our way through PSR and again must meet minimum specs. The definitions are established by an observer on the ground who looks at how defined footprints and tracks are in the snow and how clear the horizon is. The RADALT is a great tool in assisting flare height, and we cross-reference VNAV for profile management on the runway without visual approach lights. It is a lot easier to end up on an unstable profile when the visual cues in front of us are so deceptive.

We rely on the RNAV approaches to either runway. The airfield does have a TACAN which is utilised by other operators but our aircraft is not equipped. A TLS (transponder landing system) has just been installed in NZFX for the 2020/2021 season – I understand this appears in the flight deck the exact same as an ILS but is yet to be verified as usable for us.

RNZAF Boeing 757-200 Antarctica. NZ Defence Force

Ice airfield

Indeed, Australia has proposed building a multibillion-dollar permanent airfield, complete with 2.7km concrete runway, in Princess Elizabeth Land, to guarantee year-round access to Davis research station, Australia’s most southerly research station.

The plan has aroused considerable controversy among environmentalists, who fear the destruction of wildlife habitats and the project sparking similar ventures among international rivals. That rivalry, particularly with China, whose presence in Antarctica is growing, is thought by some to be the real reason behind Canberra’s keenness to establish a permanent airfield.

One of the most frequent visitors to Antarctica is Russian oversized cargo specialist Volga-Dnepr Airlines, which has recently completed its sixth programme of flights to the continent, consisting of five charter flights operated by its Ilyushin IL-76TD90VD.

The flights were operated from Cape Town to Station Novo in co-operation with ALCI, which delivered more than 200 tons of cargo essential for the work of the research stations. Station Novo has an average population of 40, while in summer this grows to around 70 with tourists and other visitors

“Each year we increase the number of certified crew members to guarantee smooth operations,” said Ekaterina Andreeva, Volga-Dnepr’s Commercial Director. “Since 2015 Volga-Dnepr has accomplished over 150 charter flights to/from Antarctica, delivering over 1,700 tons of general and special cargo.” Often, passengers fly in on the Il-76 transfer at Russia’s Station Novo to a Basler BT-67 – the turboprop-powered, modernised variant of the DC-3 – operated by Canada’s Kenn Borek Air in either ski or wheel mode for short onward ‘hops’ to other scientific bases.

The Calgary-based company, which also flies DHC-6 Twin Otters in Antarctica, has flown for several years on behalf of several scientific organisations, including the US and Australian Antarctic Programs.

It also operates two BT-67s – Polar 5 and Polar 6 – for Germany’s Alfred Wegener Institute on the southernmost continent, both for scientific missions and on logistics runs between the various international research stations.

China’s Polar Research Institute also started using the BT-67 (which it dubs the Snow Eagle 601) in 2015. The Chinese value it for its large internal fuselage volume, ability to carry varying scientific payloads up to 3,900kg and its range of up to 1,300km around China’s Zhongshan research station.

The BT-67’s ruggedness stands it in good stead in the freezing conditions. Indeed, in 2018, it was reported that no fewer than seven, operated by various organisations, were flying there.

One of the biggest single fleets is operated by the British Antarctic Survey, whose four DHC-6 Twin Otters and a single DHC Dash 7 – now very much a rara avis – fly out of a 900m gravel runway at Rothera Research Station.

The Dash-7 undertakes regular shuttle flights to and from the Falkland Islands and Punta Arenas, Chile. The Twin Otters transport scientists to field study sites. The aircraft are often outfitted to capture geophysical and meteorological data.

BAS DHC Dash 7. BASAdam Bradley

Holidays on ice

Remarkably, tourist flights even to the South Pole (or very close to it) are now available, with services from Chile using BAe 146s. It helps, however, if you have deep pockets. The current price listed by one holiday company for a return charter flight from Punta Arenas and accommodation near the South Pole runs at a cool – or perhaps decidedly chilly – $48,000.

Flying into Antarctica will never be routine... but it is not impossible.

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