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Monday, April 1, 2002

Over the Top: Flying the Polar Routes

There’s another body of water to consider for oceanic flight–the Arctic. Money and flight time can be saved, and the modernization of air traffic services in Russia, Mongolia and China makes transpolar flights even more practical.

Capt. Edward R. Hanson Jr. and David Jensen

It is cold at Eilson Air Force Base, near Fairbanks, Alaska. Forty-five degrees below zero cold. It is February 1972, and we are with a KC-135 tanker task force. Our job is to refuel reconnaissance aircraft, including the SR-71 Blackbird, which keeps an eye on the Soviet far east. The cold is hard on the airframe, engines and avionics. Heaters are plugged into the avionics bay, so the boxes don’t disintegrate when electrical power is applied.

The avionics on the tankers include a single HF radio, two UHF communications radios, a single ADF and dual ILS/VORs. We have a navigator on board who uses pressure patterns, dead reckoning, ground radar mapping and his sextant to keep us legal as we transit the North Pole. It feels great when we hit the rendezvous point and the receiver aircraft is actually where we hoped it would be.

Then and Now

Fast forward to 2002. The North Pole is now the key to cost-efficient air routes between North America and the Far East. Polar weather remains icy cold, but the political climate has thawed since the fall of the Soviet Union in 1991. The United States and Russia are now partners in opening high-value routes to airline operators. In November 1992, the two governments established the Russian/American Coordinating Group for Air Traffic Control (RACGAT–visit www.racgat.com). Among its top priorities have been establishing trans polar routes that link North America with China, Japan and Southeast Asia and modernizing air traffic control (ATC) services along those routes. Observers at RACGAT meetings include officials from Canada, North Korea, China, Mongolia, South Korea, the International Civil Aviation Organization (ICAO) and the International Air Transport Association (IATA).

RACGAT didn’t propose the establishment of trans polar routes until 1995, however, during an ICAO Pacific bureau meeting in Bangkok. The idea was revolutionary at the time. Nevertheless, in late 1998, the Russian government gave the right to open four polar routes–designated Polar 1, 2, 3 and 4–and several operators quickly took advantage of the opportunity, flying more than 500 demonstration flights over the Arctic from July 1998 to January 2001.

Cathay Pacific flew the first trans polar flight (non-revenue) in July 1998. Later that year, Northwest Airlines began flying demonstration flights over the Arctic, as did United Airlines in 1999.

"These were all revenue flights," says Gene Cameron, referring to the Northwest and United flights. Cameron is United’s manager-international dispatch and flight operations. "The demonstration flights were to prove the feasibility of these new routes." Using a B747-400, United flew 12 demo flights in 1999 and 253 in 2000.

Today three U.S. airlines make regular flights over the Arctic. United schedules daily trans polar flights from Chicago to Hong Kong and from Chicago to Beijing. Northwest has scheduled four trans polar flights weekly between Detroit and Beijing, and Continental Airlines offers four trans polar flights weekly from Newark to Hong Kong.

Cargo carriers have yet to establish regular flights over the North Pole, largely because older, heavier aircraft would require a refueling stop in Russia. However, since the Russians probably would be happy to exchange fuel for cash, trans polar cargo flights no doubt will be forthcoming.

Modern air transport jets that fly the polar routes carry similar avionics packages to those in military aircraft a quarter of a century ago, except the UHF radios have been replaced by VHF and satcom, and the navigator has been replaced by inertial reference units (IRUs) and GPS. Today’s jets still carry VOR/ILS and ADF receivers. As with all long-distance passenger flights, the aircraft are equipped with oxygen and medical gear, such as defibrilators.

Equipment and Recovery Plans

The airlines flying trans polar routes also had to establish recovery plans, i.e. readily available airports in case a jetliner is forced to land. Several Russian companies have made available to airlines their expertise in facilitating the arrangements with, and handling the language differences at, airports in their country, according to Cameron. "Generally, there are airports covering the entire Northern Hemisphere. They are no more than three hours, and usually about two hours [from a trans polar aircraft’s location]," he says.

Western airports with prime locations for polar flight emergencies include the U.S. Air Force base in Thule, Greenland; the airport at Yellowknife, Northwest Territories in Canada; and facilities in Alaska and northern Norway. According to Cameron, an aircraft’s first contact with an emergency airport–when approaching Russia, flying Polar 1 or 2–would be to Khatanga or Norilsk; for Polar 3 or 4, the first emergency airport to contact would be Tiksi. All of the airports have 9,000- to 11,000-foot runways. Necessary as these emergency airports are, United "has made more than 800 polar flights across Russia since 1999 and has had no reason to land there yet," he adds.

Communications

United and Continenal aircraft traversing the North Pole are equipped with the satelliate-based Future Air Navigation System (FANS). They have satellite communication receivers, as well as VHF data and HF voice. Northwest aircraft, which are not FANS-equipped, rely on HF voice and the HF airborne communications addressing and reporting system (ACARS).

On Polar 1, 2 and 3, United and Continental pilots use satcom until their aircraft reach about 82 degrees north latitude, at which point they lose line-of-sight connection with the Inmarsat satellites and must switch to HF voice communications. Polar 4 skirts the northern latitudes enough to allow satcom coverage throughout a flight.

"You lose most of VHF [communication] when you head north of Hudson Bay," says Cameron.

For polar route pilots, HF voice communications to air traffic control in the Western Hemisphere are provided by Arctic Radio, based in North Bay Ontario, for the Edmonton, Alberta, air traffic control center. Managed by Nav Canada, Arctic Radio has HF antennas located at Cambridge Bay, Northwest Territories, which are remotely operated from the North Bay International Flight Service Station, according to John Metzger, program manager-HF voice services for ARINC.

Nav Canada officials say Arctic Radio will make available HF data link for position reporting by autumn 2002 and provide two-way HF data link communications by the first quarter of 2003.

Airlines flying the polar routes also want ARINC to expand its HF voice service. In response, ARINC plans to add HF voice to its GLOBALink/HF data link (HFDL) station in Barrow, Alaska. "We plan to have it available in the May/June [2002] time frame," says an ARINC official.

Barrow’s HF voice station will be unique. "Due to environmental difficulties associated with antenna installation at Barrow, we will, for the first time, use TX [transmit] multicouplers, so we can operate two HFDL transmitters and a new voice transmitter off of the existing antenna," says Metzger.

ARINC provides full HFDL coverage for the polar routes, with ground stations in Krasnoyarsk, Russia; Reykjavik, Iceland; Limerick, Ireland; South Hampton, N.Y.; San Francisco; and Barrow. This will improve a communications service that United pilots described as being only "fair" during the airline’s demonstration polar flights.

Of course, as the sun moves through its solar maximum activity cycle, pilots flying the polar routes can expect some interference with HF voice communications. HF radio waves are reflected by certain layers in the ionosphere due to the solar winds’ effect on the "skip layer," explains Roy Oishi, an ARINC fellow. The signal bounces between the skip layer, which moves up and down during the day/night cycle, and the ground, and this can impact radio reception. Increased radiation in the solar winds also can affect the signal. In fact, the trans polar pilots can view these winds from the cockpit as the aurora borealis.

Navigation

While little can be done to improve HF voice communications on polar routes, adverse effects on HFDL "can be dealt with," says Oishi. "There are multiple data link ground stations around the pole that use multiple frequencies. An onboard communication management system thus can automatically seek the best frequency for a data link transmission."

GPS and IRUs provide navigation over the polar routes. United and Continental aircraft are equipped with dual GPS and triple IRUs, with the former receiver updating the latter unit. Northwest pilots rely on triple IRUs.

Should a Continental or United aircraft lose the GPS signal, the navigation management system automatically provides an elegant degradation to IRU-only navigation. (Elegant degradation is the programmed step down in navigation accuracy to a lesser level, or lesser figure of merit [FOM], and is preferred to the alternative "catastrophic failure" and loss of all navigation capability.) The flight management system (FMS), which monitors the health of the navigation sensors to determine their current actual navigation performance (ACP), will alert the crew should the GPS signal be denied.

The GPS navigation function provided is several orders of magnitude better than what the cold warriors experienced from navigators. "Unlike satcom voice or data link, GPS does not lose its signal [because of a line-of-sight break] when flying the polar routes," says Cameron.

Surveillance

Russia has divided the Arctic region into two flight information regions (FIRs). Aircraft entering Russian airspace on Polar 1 and 2 are controlled by the Murmansk ATC center near the Finnish border. And those entering on Polar 3 and 4 are under Magadan’s watch. Located on Russia’s east coast, Magadan is the country’s only FANS-equipped facility. Established with ARINC assistance, it was commissioned in 2001. Magadan, is equipped to receive automatic dependent surveillance (ADS) messages and send and receive controller pilot data link communications (CPDLC), "which takes care of the language barrier," Cameron notes. CPDLC also increases communications clarity and throughput, and makes miscommunications of position fixes less likely. A VHF ACARS ground station also is located at Magadan.

Until Nav Canada permits flight following using HFDL, ADS in Magadan remains the one exception to the old-fashioned way pilots on the polar routes report their positions–by HF voice. It also means the high frequency band can be used over Canadian airspace only for aeronautical operational control (AOC) messages.

HFDL would reduce pilot workload, as the communication management system automatically assumes the task of searching for and selecting the best frequency. It also costs less than satcom.

ADS in Magadan fills in the gaps in Russia’s ground radar coverage. The Magadan situation display provides controllers with a digitized image of the information from primary and secondary radar and ADS reports from suitably equipped aircraft. "The Russians mainly have primary radars, though secondary radars are being installed," says Cameron.

Farther down the polar routes, Mongolia, too, has FANS-equipped ground facilities (equipped by Raytheon). And so does the People’s Republic of China, though not all of the facilities are operational for the polar routes, according to Cameron. However, China is agressively modernizing its air traffic services and has just installed a new FANS workstation in Harbin (now in test), which will provide a new entry point into Chinese airspace for Polar 4.

Until new ground facilities are commissioned, trans polar flights are allowed only one entry point into Chinese airspace. "They’re working to improve that," says Cameron. "We hope to see more [operational] flexibility granted this year, so we can have a couple more entry points. That will cut our flight times even more, by 15 to 20 minutes."

Russian ATC Modernization

Pilots with Northwest Airlines, United Airlines and American Airlines, who flew demonstration flights over the Arctic region, generally praised Russia’s handling of air traffic control (ATC). "Exceptional" and "excellent" were words in post-flight reports to describe the Russian ATC service.

But Russian ATC needs to modernize and, recognizing that fact, the country’s civil aviation administration drew up a 10-year upgrade and consolidation plan. Airlines flying the polar routes no doubt will appreciate the fact that modernization along those routes will receive top priority. A contract with a Western ATC integrator is anticipated this spring and may be announced in late May in connection with President Bush’s visit to Russia.

The 10-year plan would reduce Russia’s 128 area control centers (ACCs) to 22 centers. (It should be noted, however, that Russia has been quite liberal in describing an area control center. Two people manning a radar installation might be called an ACC.) The country also hopes to use as much of its existing equipment as possible, and its plan initially called for an assessment of Russia’s ATC assets. "Russia probably needs more radars, better ground-to-ground communications and better weather and meteorological data–in other words some weather radar," says Bob Bitzberger, head of Lockheed Martin ATM’s representative office in Russia and the Commonwealth of Independent States (CIS). "We would integrate much of the existing equipment, though some of it must be upgraded." (Pursuing the Russian ATC contract, Lockheed Martin ATM established an office in Moscow in August 2001.)

The 10-year plan would be divided into three phases:

  • Phase 1–would modernize facilities serving the four routes crossing the poles plus the four routes crossing Siberia, east and west. The effort should take seven years to complete, says Bitzberger.

  • Phase 2–would upgrade ATC in Russia’s far east and take about three years to complete.

  • Phase 3–would modernize the remaining areas of Russia in the west and would also take about three years to complete.

The modernization phases would overlap, says Bitzberger. The total program should take no more than 10 to 11 years to finish.

Russian authorities expect that revenue from air traffic services for trans polar routes will pay for much of the upgrade program. They estimate income from overflight fees will reach $180 million between 2001 and 2010. Currently, two to three trans polar flights are made daily. But Russian authorities estimate 40 flights each day by 2010.

Money and Time Saved

So how beneficial are the trans polar routes to the air carriers flying from North America to the Far East? It can vary day to day but, generally, money and time are saved flying over the Arctic.

Gene Cameron, manager-international dispatch and flight operations for United Airlines, explains how much the savings from trans polar flights can vary. "Earlier this month, the fastest non-polar time from Chicago to Hong Kong was 16 hours and six minutes," he told Avionics Magazine in late February. "On Feb. 15, taking into account the winds at different elevations, we determined that we could fly Polar 3 and reach Hong Kong in 15 hours and four minutes.

"However, if you go back to Feb. 7, we determined the trans polar flight to Hong Kong would take 14 hours and 42 minutes," he adds. "So every day, you look at both the polar and non polar routes.

There often is little high wind over the Arctic Ocean, and that is particularly beneficial for North America-to-Far East flights during the winter months, when pilots choose to avoid the strong jet streams coming out of Japan toward Alaska.

Nav Canada and the Federal Aviation Authority of Russia conducted a feasibility study that calculates the time and money saved from flying the polar routes.

Polar First

Polar routes may have been established to benefit most North American carriers flying to the Far East, but Russians boast making the first trans polar flight, from their country to the United States. In the summer of 1937, a crew led by Valcry Chkalov departed Moscow and flew over the North Pole to the United States. The flight took 63 hours and 16 minutes.

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