Silencing the Arctic Mammoth

Published May 23, 2016
By Air Force Capt. Christopher Arnold
301st Intelligence Squadron

JOINT BASE ELMENDORF-RICHARDSON, Alaska -- For half a century, the "Elephant Cage" has cast a shadow over the Alaska landscape, silently collecting and finding the direction of communications signals, guarding against adversary threats and intentions. The intelligence collected informed our nation's and allied decision makers, from presidents to warfighters. In later years it fulfilled a crucial role aiding in navigation and direction-finding for civilian and military search and rescue missions. After five decades of service, this symbol of intelligence operations is being retired.

The AN/FLR-9 (commonly pronounced Flare-9) is a large circular antenna array affectionately referred to as the "Elephant Cage" because of its massive 40-acre footprint and 120-foot tower height. Its design was based on the German Wüllenweber antenna. During World War II, German naval technicians in a secret research and development program designed and built the original antenna. Following the war, the original structure was destroyed according to terms negotiated under the Potsdam Conference, and a secondary system was disassembled and brought back to the U.S. for an in-depth engineering analysis.

Built in 1966 at the height of the Cold War at what is now Joint Base Elmendorf-Richardson, the antenna is the last of eight systems which originally comprised a worldwide network. Each system could intercept and directionally locate high-frequency radio transmissions up to 4,000 nautical miles away. Over time, these structures succumbed to many different fates.

Three were dismantled as a result of base closures: Ramasun Station, Thailand in 1975; San Vito Air Station, Italy in 1993; and Royal Air Force Chicksands, England in 1997.

Another at Karamursel Air Station, Turkey, was demolished following a conflict over foreign aid to Greece in 1977. The array at Clark Air Base in the Philippines was irrevocably damaged by the eruption of Mount Pinatubo in 1991 and subsequently converted to a covered amphitheater.
Most recently, Misawa Air Base, Japan, deactivated their AN/FLR-9 in 2012 and demolished it in 2015.

Initially maintained and operated by the United States Air Force Security Service, and locally by the 6981st Electronic Security Squadron, today, the operation and maintenance of the AN/FLR-9 is executed by the men and women of the 373d Intelligence, Surveillance, and Reconnaissance Group and a cadre of trained civilians.

This month that will all change, when the last of these mammoth structures is scheduled to be deactivated and powered down for the first time in 50 years.

"The development and diverse geographical deployment of these systems was a noteworthy intelligence achievement for the period," said Air Force Col. Suzanne Streeter, 373d Intelligence, Surveillance, and Reconnaissance Group commander. "Advances in technology, along with the high cost of maintenance and availability of replacement parts, have shifted the AN/FLR-9 antennas across the Air Force from an operational capability to historic monuments."

Though upgraded over the years, it is a testimony to the engineering and workmanship of the antenna that many parts are still original and have never been repaired or replaced. The antenna array is eligible for the National Register of Historic Places. There is already interest in preserving the site, similar to the Nike Missile Site on Site Summit near JBER's eastern edge.

"I've been fortunate to have three tours flying fighters at Elmendorf, and I've seen a lot of changes since my first sortie here in 1994, including the runway orientation," said Air Force Col. Charles Corcoran, 3rd Wing commander. "One thing that never changed was the 'elephant cage.' Whether sighting it from long distance on a beautiful clear day in Alaska, or catching a glimpse of it after breaking out of the clouds on an instrument approach, a pilot always knew he was home as soon as the 'elephant cage' was visible."

Efforts are currently underway to explore the conservation of the antenna to honor its 50 years of service.