Document created: 31 December 03
Air University Review, May-June 1972

Mac’s Role in Deep Freeze

Edward J. Belz 

A New 10,000-foot runway is constructed every year for the Military Airlift Command’s annual participation in Operation Deep Freeze, which supports United States scientific and other programs in Antarctica.

The old runwayspread atop 95 inches of icesoftens, melts, cracks, and drops into the 900-foot-deep waters of McMurdo Sound during the waning days of the Antarctic austral summer. Nature then begins the rebuilding job in the early days of autumn (March through June), and by the time the severe temperatures and winds of winter subside, the ice at the runway location is of sturdy thickness, capable of accommodating aircraft with gross weight of more than 250,000 pounds.

Ice borings determine the actual thickness and provide the signal for the wheeled aircraft to begin their airlift role in resupplying the vast scientific operations in the Antarctic. 

In anticipation of this signal, planning for the Military Airlift Command’s participation in Deep Freeze 72 started in spring 1971. Climaxing this planning and staging-out of Quonset Point Naval Air Station, Rhode Island, for the overseas operation and out of Christchurch, New Zealand, for the flights to the icethe C-141 Starlifters begin their missions in early October and continue until the McMurdo Sound runway is closed down for the year. The life span of the icy airstrip is determined by the weather; a “hot” summer (with temperatures reaching the high 30s) can cause an early closure, as it did in mid-season last year.

On cue, activity at the Antarctic stations blossoms with the milder weather. A tremendous amount of workexperiments and logistics activities in support of these experimentsmust be accomplished during the brief four to five months’ respite from Nature’s frigid grip. Pressed into service are icebreakers, tankers, cargo ships, helicopters, bulldozers, electronic vans, generators, and many other vehicles and equipment. In comparison with the overall operation, the Military Airlift Command’s assigned mission is modest. Yet, from an airlift standpoint, MAC’s role is formidable. This year, C-141s were to carry 1700 passengers, with their personal gear, and almost a million pounds of cargo to the ice.

The U.S. Navy, serving as executive agent for the Department of Defense in providing logistic support for the U.S. Antarctic program, has the major role. The U.S. Coast Guard and other government agencies also are involved.

Starting in late September, MAC Starlifter aircrews began their role in Deep Freeze 72, flying 16 missions from Quonset Point to Christchurch. Three MAC commercial contract flights also were scheduled for the deployment to Christchurch.

From Christchurch, the C-14ls fly 40 turnaround resupply missions to the ice on McMurdo Sound. These missions were assigned to the 438th Military Airlift Wing of the 21st Air Force at McGuire AFB, New Jersey. In addition, a 21-man airlift control team from the 438th and a 6-man detachment from the 61st Military Support Wing at Hickam AFB, Hawaii, provide staging, maintenance, and other ground support at Christchurch.

C-14l major maintenance normally is performed at Christchurch. Minor maintenance is provided by aircrew members on the ice. Yet if major maintenance is required, the parts and a maintenance crew may be flown to the ice and the work done there.

The mission route from the Atlantic Coast to McMurdo Sound covers more than 11,000 miles, including enroute stops at Andrews AFB, Maryland; Travis AFB, California; Hickam AFB, Hawaii; Pago Pago in American Samoa; and Christchurch before the final 2117-nautical-mile flight to the ice. While the overall route is a long one, the real challenge for the aircrews does not really start until the takeoff from New Zealand on the final leg.

Crews are augmented for the flight to the ice because they are on a turnaround mission with time on the groundor on the icejust long enough to offload the cargo, refuel and obtain other basic ground support, take on retrograde cargo, and begin the return flight. The crew includes the aircraft commander and two other pilots, two navigators, engineers, and loadmasters. There is only one especially imposed qualification: the aircraft commander must have participated in a previous flight to the ice. If the aircraft commander has not made a previous flight to the ice, then his initial trip to McMurdo is made under the supervision of an ice-qualified flight examiner.

Grid navigation is required for all flights to McMurdo. The navigators usually do a little brushing up on grid navigation during the long flight from Pago Pago to Christchurch. That leg provides sufficient time for them to check out their gyroscopes and compare their grid procedures with the flight data from the C-141’s ASN-24 primary computer. Without accurate heading input, the computer cannot produce the desired navigational computations south of 56 degrees. Since McMurdo is 1300 miles south of this point, the accuracy of the navigator’s grid procedure is of critical importance.

The margin for navigational error is slim, for return to Christchurch is the only alternative to landing on the ice at McMurdo. This fact, plus the Antarctic’s extremely unpredictable weather, makes the point of safe return a matter of serious concern. Missions are planned with sufficient fuel to arrive overhead at McMurdo and return to the alternate, which is Christchurch, in the event landing cannot be made. 

While the flight is over water all the way from Christchurch to Antarctica, two navigational fixes can be made en route: the first at Campbell Island, which is about one-third of the overall distance out of Christchurch; the second at the Balleny Islands, about 200 miles west of the flight pattern, about midway between the takeoff and landing points. A radar fix can be made on these islands to check the accuracy of the grid procedures. And the last 100 miles of the polar flight is within sight of the shoreline of Victoria Land, Antarctica.

Generally, the C-141 is the only aircraft in the sky above 25,000 feet, and the aircrew can select its own altitude without worrying too much about hemispheric separation. Normally, however, the Starlifters are flown down to the ice and back at 37,000 feet, staying at that altitude as long as possible to conserve fuel. Descent is almost always initiated VFR within 75 miles of destination.

Aircrews are enthralled by their first sight of Antarctica. One pilot, a veteran of six ice landings and still awed at the thought of the impressive wintry landscape, commented: “Destination on the way down means Antarctica stretched out before youmiles and miles and miles of bleak, lifeless, mountains of snow and ice, glaciers of immense proportionsa spellbinding sight, unlike any other on earth. Unpolluted, clear, and cloudless skies with visibility of 200 miles in every direction. Beautiful, yet desolate. Serene, yet terrifying.”

A navigational landmark of immense gratification to the navigator as it looms into view is Mount Erebus, an active volcano that sits at the edge of McMurdo Sound. As the aircraft arcs around the volcano, the grid north oriented TACAN is picked up on the instrument board. A combination of GCA, TACAN, and the airborne radar computers goes into action to guide the aircraft onto the ice runway.

Pilots freely admit a moment of anxiety as they touch down on the ice, despite repeated assurances from others with experience that there is little difference from regular landings. And it is true, the landings are accomplished without difficulty. The runway, damagingly rough one day and smooth the next, is maintained by efficient Navy ground crews. They continually scrape the rough spots and then “blow” three to four inches of snow back on the 10,000-foot strip. The snow acts as a slowing agent, and full reverse thrust is seldom required to halt the rolling aircraft. In fact, power frequently must be applied to taxi off the runway.

The 10,000-foot runway is more than ample for the landing, the roll, and the taxiing. A very physical incentive favors keeping the aircraft on the runway: at the end of the McMurdo Sound flat is the Ross Ice Shelf, a towering mass of perpetual ice that rises like a wall.

Exact measurements are taken on the thickness of the ice and on the impact and load effects of the aircraft landing and parking on the ice. The immediate parking area of a fully loaded C-141 is depressed a half inch, according to these measurements; the landing impact causes less of a depression because the ice is thicker in that area.

The flight from Christchurch to the ice, the navigation to the far southern reaches of the Pacific Ocean and into the Ross Sea, and the chilling first sight of the vast, almost lifeless continent-all build up to a crescendo for the landing. After these challenges, emotions, and thrills, the return flight to Christchurch is like a bicycle ride in the park on a Sunday afternoon.

Hq Military Airlift Command


Contributor

Edward J. Belz is an Information Officer, Military Airlift Command. After 21 years with a midwestern daily newspaper as reporter and city editor, he became associated with the Air Force in 1967, first with AFCS and in 1969 with MAC. Mr. Belz attended St. Louis University and the American Press Institute, Columbia University. He served more than four years in the Army during World War II, including assignments in North Africa and Italy.

Disclaimer

The conclusions and opinions expressed in this document are those of the author cultivated in the freedom of expression, academic environment of Air University. They do not reflect the official position of the U.S. Government, Department of Defense, the United States Air Force or the Air University.


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