Jan Jorgensen reports on the specialised missions undertaken by the Royal Danish Air Force’s Eskadrille 721.
THE DEMANDING geography of Denmark, including Greenland and the Faroe Islands, presents the Royal Danish Air Force (RDAF) with a real challenge.
For over 65 years the primary role of Eskadrille 721 [Esk 721) at Valose Air Base outside Copenhagen has been to provide an airlift capability, while other missions involve it in sea-surveillance, ice-reconnaissance, search-and-rescue, and medical evacuations throughout the Arctic.
Over the years, these roles have been carried out by a variety of aircraft. However, three types have provided the backbone of the fleet for more than 25 years, the PBY-6 Catalina, the C-47 Dakota and the C-54 Skymaster. The legendary Catalina was phased out during the 1970s, and the C-54 was replaced by three Lockheed C-130H Hercules. The C-130 has multi-mission capability, and is therefore ideal for Esk 721 operations even though it was purchased without any special modifications, other than the recently introduced Radar Warning Receiver system and chaff/flare dispensers. It soon became the RDAF’s main workhorse, performing airlift duties in the European and Arctic theatres, as well as carrying out specialised missions, such as fishery inspection in the protected zones around Greenland and the Faroe Islands.
When these zones were extended in 1977 to 200nm (370km) from the coastline, the patrol area increased dramatically to 328,210 square miles (850,000km²) – an area equivalent to Great Britain, France, Holland and Belgium put together. It soon became clear that the C-130 was no longer ideal for this particular mission and so the RDAF began looking for an aircraft with sufficient speed, range and equipment, to cope with this task. Consequently, during the 1980s, the venerable C-47 was replaced by three Gulfstream III Special Mission Aircraft.
The G-III SMA is a heavily modified version of the G-III business jet, tailored to Esk 721 Arctic operations by the installation of APS-127 surveillance radar in the nose, and a large cargo door on the right-hand side of the fuselage. The cabin interior layout can be further customised with the use of interchangeable modules (comprising roller conveyor systems, passenger seats, racks for medical equipment, communication and navigation consoles) according to the requirements of each mission.
The Faroe Islands are normally served by Esk 721 flights from mainland Denmark, however, the vast Greenland area has a G-III permanently stationed at Sondrestrom Air Base on the west coast, just north of the Arctic Circle. The Luftgruppe Vest detachment includes two technicians, an avionics specialist and a flight engineer, so that minor malfunction on the G-III can be dealt with immediately. Major repairs, and fortunately they are few and for between, require assistance from the Vaerlose homebase. The Sondrestroni AB detachment is tasked with fishery inspection and ice-reconnaissance — while its very presence helps to maintain sovereignty of the Greenland airspace. The detachment is also kept on constant alert for medical evacuation and search-and-rescue purposes.
The economic zone around Greenland covers 212,372 square miles (550,000km2) and is patrolled in segments. For optimum fuel economy, flights to and from the patrol areas are normally made at a cruising altitude of 39-41,000ft (11,800-12,500m) and a speed of about 475kts (880km/h), before descending to the area of specific interest (defined by the extent of the ice-pack, the activity of reported fishing vessels, or the probable concentrations of fish).
Surveillance is typically carried out at 5,000ft (1,500m) and 300kts (556km/h) to get the most out of the radar, which has an effective range of 80nm (128km) at this height. When the advanced Texas Instruments APS-127 radar has identified an interesting target, its position is relayed to a double Litton 72R Inertial Navigation System which automatically controls the Sperry SPZ-800 autopilot. Thus the G-III can literally fly itself through a search profile determined by radar-targets! However, manual control is resumed when visual identification has to be made, with descent to as low as 100ft (30m) in order to register possible violations and secure photographic evidence. The inspection is carried out in conjunction with Danish naval vessels and Lynx helicopters as these are left with the task of actually boarding suspect craft.
Fishery inspection missions around the Faroe Islands are flown out of Vaerlose AB, with a refuelling stop at Vagar airfield on the Faroes. The G-III is able to cover the entire patrol area of some 115,840 square miles (300,000km2) and make the 1,677 miles (2,700km) round-trip from/to Vaerlose in eight hours. Fishery inspections are normally flown twice a week, and nearly 85% of the total number of G-III flying hours are spent in the North Atlantic area.
The Arctic region is an extremely harsh environment with freezing temperatures, storm-force winds and perpetual darkness throughout most of the winter months. Weather prediction in remote areas is limited and aircrews are often confronted with unpleasant surprises. There are few airfields able to take the C-130 and G-III and those that can are located far apart. Besides Sondrestrom there are only two airfields with facilities for over-night stops, Thule Air Base in the north and Narsarsuaq Airfield in the south of Greenland. Secondary fields able to offer refuelling stops, include Station North, Mestersvig and Kulusuk, all with short gravel runways. Nearby Keflavik Air Station in Iceland is often used for staging and diversion.
With its 5,250ft (1,600m) gravel runway covered by snow or ice for most of the year, Station North is the world’s northernmost permanently manned airfield, located at a latitude of 83° north, only some 560 miles (900km) from the North Pole. At least five voluntary military personnel are based at Station North all year round — among other tasks, they support the Sinus patrol; a small Danish unit which patrols the freezing wilderness of northern Greenland with dog sledges. In order to make the held available for aircraft operations Esk 721 supplies a year’s worth of aviation fuel to Station North every spring. During the six-week long operation -Brilliant Ice some 400 tonnes of aviation fuel is airlifted from Thule to Station North, requiring at least 40 G130 return flights.
Esk 721 does not normally need to fit skis to its aircraft for work in the Arctic, as the low and compact undercarriage of the C-130 has proved to be well suited to operations on hard-packed snow or ice. In exceptional circumstances, Esk 721 has even successfully operated the C-130 from ice-caps off the Greenland coastline — though this could never become a routine procedure as the thickness of the ice must be examined very carefully first!
Once a month the G-III at Sondrestrom performs a surveillance flight round the entire Greenland coastline to demonstrate Danish sovereignty, while at the same time keeping an eye out for wrong-doers or people in distress. These two-day missions are flown at an altitude of only 5-10,000ft (1,500-30,000m) and are very popular with the aircrews as they get a chance to view the spectacular Greenland scenery.
The last words should go to the squadron crews who best sum up Esk 721 operations in the Arctic as akin to «a long-standing love/hate relationship».