EGLIN AIR FORCE BASE, Florida —
It’s a big year, not just for the US Air Force.
As people across the country prepare to celebrate the branch’s 75th anniversary later this summer, those at McKinley Climate Lab at Eglin Air Force Base, Fla., recently celebrated their facility’s diamond anniversary. .
The first tests at the MCL took place on May 24, 1947, before the official establishment of the Air Force by about three months.
In the 75 years since, the unique capabilities available at MCL have been used to perform a variety of climatic tests for the Department of Defense, other government agencies and private industry. From arctic frost to searing heat and desert sand to jungle humidity, any climatic environment in the world can be simulated in the installation.
“For all DOD agencies, environmental testing at MCL is an essential step in establishing a proven military capability to meet our global commitments specifically articulated in the National Defense Strategy,” wrote Kirk Velasco, Director at the retirement of the MCL, in a comment published in Mach high in 2020. “The results achieved from the wide range of aircraft and equipment tested at MCL have been a major factor in maintaining the United States’ position as the world’s leading military power.”
Today, the MCL is operated by the 717th Test Squadron, 804th Test Group, Arnold Engineering Development Complex.
“On behalf of the 717th Test Squadron, I would like to express my gratitude and appreciation to everyone who has worked at MCL for the past 75 years,” said Melissa Tate, MCL Site Manager. “My congratulations to MCL and I look forward to an equally successful future.”
At the start of its operations, the MCL was part of the US Army Air Forces. This component was soon separated from the Army and became its own military branch when the Air Force was founded on September 18, 1947.
Prior to the MCL, there was the Cold Weather Testing Detachment stationed at Ladd Field in Fairbanks, Alaska. The Air Force designated this site as a cold weather test facility in 1940.
The United States’ prior involvement in World War I meant that international warfare was on the table, and the military could find themselves engaged in combat virtually anywhere on the planet. The ability of military aircraft and equipment to maintain operability and reliability in the harshest climates had to be guaranteed.
This was the mission of the cold weather testing detachment at Ladd Field. During a two-year period after its activation in 1940, the detachment successfully established basic operational and maintenance requirements for aircraft in the Arctic, conducted experiments on uniforms and cold weather rations and to experiment with solutions to Arctic flight problems.
Testing at Ladd Field ceased after the December 1941 attack on Pearl Harbor. It was feared that installations in Alaska would also be attacked, so it was decided that all military aircraft there would be used to defend the state.
The Cold Weather Testing Detachment was reactivated in 1942, and by that winter testing had resumed at Ladd Field, as the importance of such efforts was recognized. However, the issues present since testing began at Ladd Field continued to be encountered. Despite its position on the globe, cold weather testing at Ladd Field was often inconsistent. Cold-weather testing there was conducted in an open-air environment, which essentially involved subjecting aircraft and equipment to outdoor conditions. However, it was difficult to predict when temperatures would reach the levels required for testing. When they did, those temperatures sometimes didn’t stay low enough long enough to meet testing needs.
In addition to suggesting that US planes would be serviceable at minus 65 degrees Fahrenheit, then-Lt. Colonel Ashley McKinley is credited with suggesting the construction of a refrigerated aircraft hangar to allow cold weather testing under controlled conditions. Headquarters for these tests was reassigned to the more temperate Eglin Air Force Base, and plans for the facility suggested by McKinley were approved in 1944. Construction began shortly thereafter.
The first tests at MCL consisted of submitting a B-29 Superfortress, a C-82 Packet cargo plane, a P-80 Shooting Star, a P-51 Mustang, a P-47 Thunderbolt and an R5D helicopter, as well as trucks, tanks and clothes, at a temperature of minus 70 degrees Fahrenheit. The tests were considered very successful.
In 1971 the refrigerated hangar was renamed the McKinley Climatic Hangar in honor of McKinley, who had died the previous year.
Over the years, the facility that would become known as the McKinley Climatic Laboratory expanded its offerings beyond arctic and subarctic testing. The laboratory now consists of five test chambers used to prove the operational reliability of the systems tested in the extreme climatic conditions encountered around the world. In addition to large aircraft, items tested in these chambers include engines, tanks, missile launchers, shelters and automobiles.
“The MCL is the only facility in the world that can contain and test a full-scale operational aircraft in extreme weather conditions,” Tate said. “This facility can produce, on any given day, any extreme weather environment in which to perform a desired test.”
The main chamber is a large environmental test chamber that measures approximately 252 feet wide, 260 feet deep, and 70 feet high. It is used to test large items and systems for aircraft. The chamber is capable of producing a temperature range of minus 65 degrees Fahrenheit to 165 degrees Fahrenheit. Climatic conditions such as ice, snow, wind, rain, solar radiation and sand can be simulated during the tests.
The Equipment Test Chamber has the same capabilities as the Master Chamber. It is 130 feet long, 30 feet wide, and 25 feet high. This chamber is typically used to test jet engines, small vehicles, and turbine ground generators.
Ambient or hot test conditions can be produced in the Sun, Wind, Rain and Dust chamber. This chamber can also be used to create wind-blown rain at rates of up to more than two dozen inches per hour and heavy sand and dust storms.
Due to the corrosive properties of salt spray test conditions, the salt spray chamber was designed to provide a test chamber that is not in close proximity to other chambers. This chamber has two steam-fed heat exchangers that create the temperature to perform the salt spray test that simulates corrosive environments, such as coastal areas.
The smallest of the five chambers, the Altitude Chamber can create pressure altitudes as high as 80,000 feet, as well as perform rapid decompression tests to simulate sudden pressure losses in the aircraft cabin.
“Simulating extreme weather conditions is very challenging for the facility,” said MCL plant engineer Jay Skipper. “To remain in operation after 75 years is a testament to the original design and construction.”
Examples of aircraft tested more recently at MCL include the F-117A Nighthawk Stealth Fighter, C-130J Super Hercules, F-22 Raptor, F-16 Fighting Falcon, B-2 Spirit bomber, and HH -60W Jolly Green II combat search and rescue helicopter.
“The past 75 years of successful climate testing speaks volumes about the dedication to mission and commitment to our customers of all members of the laboratory who support its operation, past and present,” said William Higdon, MCL Technical Advisor. . “There really is no cooler place to test, and I know we will continue to support our nation’s fighter with the same passion for many decades to come.”
In 1987, the MCL was named a National Historic Mechanical Engineering Landmark by the American Society of Mechanical Engineers. The following decade it was added to the National Register of Historic Places.
“It’s pretty impressive that MCL is the only facility on the planet that can do what we’re doing,” said Michael Burch, senior field engineer for the MCL facility, who has worked at the lab for nearly 25 years. “It makes you proud to be a part of it all.”
Editorial Note: This article includes information from the National Park Service itinerary “Aviation: From Sand Dunes to Sound Blasts”, an American Society of Mechanical Engineers pamphlet on MCL, and an Army study titled “Cold Weather Testing in Alaska: 1940-1970”. ”