EXECUTIVE SUMMARY
INTRODUCTION
The U.S. Antarctic Program (USAP) relies on aircraft operating between
Christchurch, New Zealand, and McMurdo to provide nearly all personnel support
and a considerable amount of cargo transport to the continent, excluding support
for Palmer Station on the Antarctic Peninsula. The first flights of the season land on
a deep snow skiway at Williams Field in late August using ski-wheel-equipped LC-
130 Hercules aircraft. In October, the main body of personnel fly to McMurdo in
wheeled C-130 Hercules, C-141 Starlifter, and C-5 Galaxy aircraft. These aircraft land
on a runway of first-year sea ice. The sea ice runway is used by these conventional
(wheeled) airplanes until its surface strength deteriorates in mid-December.
Until the 199293 season, the USAP was limited solely to the LC-130s for all air
transport from the time the sea ice runway closed throughout the remainder of the
season. There are now very few LC-130s available: five owned by the National Sci-
ence Foundation and operated by the U.S. Navy, and four contracted from the New
York Air National Guard for brief periods. With the many requirements for their use,
a backlog of personnel and crucial cargo normally occurred that severely constrained
the Program during mid- and late season.
To alleviate this problem, the USAP sought a means of utilizing conventional air-
craft in the latter part of the austral summer. However, this required a reliable run-
way capable of supporting wheeled aircraft. Candidates included runways on
multiyear sea ice, on glacial ice, and those made from crushed rock or compressed
snow.
RUNWAY DEVELOPMENT
Beginning in the 198990 summer season, engineering studies were directed at
determining the feasibility of producing a wheeled aircraft runway on the Ross Ice
Shelf near McMurdo, specifically for use during the period after the sea ice has dete-
riorated. The Pegasus runway was carefully sited in an area with a thin, but perma-
nent and complete, snow cover. This snow is underlain by a contiguous mass of
glacial ice that is derived from natural seasonal meltwater (near the surface) and ice
formed by metamorphosis of snow. The supply of highly reflective snow available
at the Pegasus site is necessary as a source for protecting the runway from deteriora-
tion due to the effects of absorbed solar radiation.
Construction
The snow cover was stripped from a surveyed 10,000- 300-ft (3050- 91-m) area
to expose the undulating ice surface. This was completed during the 1991-92 season
along with rough grading and "filling" of low areas by flood water from a portable
snow melter.
Beginning in August of 1992, overwinter snow was removed from the area. A
survey of the ice surface was used to establish the desired grade for the runway in
order to minimize construction. A laser-guided grader with a specially built chisel-
tool blade was used to level the ice surface to a smoothness in excess of published
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