McKinley Climatic Laboratory
Encyclopedia
The McKinley Climatic Laboratory is a both an active laboratory and a historic site located in Building 440 on Eglin Air Force Base
, Florida
. The laboratory is part of the 46th Test Wing
. In addition to Air Force testing, it can be used by other US government agencies and private industry.
On October 6, 1997, it was added to the U.S.
National Register of Historic Places
. The laboratory was named a National Historic Mechanical Engineering Landmark by the American Society of Mechanical Engineers
in 1987.
designated Ladd Field in Fairbanks, Alaska
as a cold-weather testing facility. Because sufficiently cold weather was not predictable and often of short duration, Ashley McKinley suggested a refrigerated airplane hangar
be built. The facilities were constructed at Eglin Field
.
The first tests started in May 1947. Airplanes that were tested included the B-29 Superfortress
, C-82 Packet
, P-47 Thunderbolt
, P-51 Mustang
, P-80 Shooting Star
, and the Sikorsky H-5
D helicopter. More recently, it has tested the C-5 Galaxy
, the F-117, the F-22 and the Boeing 787
.
On 12 June 1971, the hangar was dedicated at the McKinley Climatic Hangar in honor of Col. Ashley McKinley, who suggested the facility and served at Eglin during its construction.
The main chamber is 252 feet (77 m) wide, 201 feet (61 m) deep, and 70 feet (21 m) tall at the center of the hangar. It was constructed to hold aircraft as large a B-29, its size also fitting the larger Convair B-36 Peacemaker. In 1968, a 60 feet (18 m) by 85 feet (26 m) extension was added. It now has 55000 ft2 working area. This allows it to test aircraft as large as a C-5A. Under hot conditions, it can achieve 165 °F (74 °C).
The All-Weather Room is 42 feet (13 m) by 22 feet (7 m). It has a temperature range from -80 °F to 170 °F (77 °C). Rainfall can be as high as 15 inches (381 mm) per hour and the wind can be as high as 60 knots (33 m/s). Snow can be made in the chamber.
The Temperature-Altitude Chamber is 13.5 feet (4.1 m) by 9.5 feet (2.9 m) with a height of 6.9 feet (2.1 m). Altitudes up to 80000 feet (24 km) can be simulated. The temperature range is -80 °F to 140 °F (60 °C).
The engine test cell was originally used for aircraft engines. It was about 130 feet (40 m) by 30 feet (9 m) with a height of 25 feet (8 m). It is now called the Equipment Test Chamber and is used mainly for tank
s, trucks, and other equipment. The original building had small tests rooms for desert, hot, marine, and jungle conditions. These have been eliminated.
The original floor of the building was constructed of reinforced-concrete
slabs that were 12 inches (30 cm) thick and 12.5 feet (3.8 m) square. The slabs rested on 13 inches (33 cm) of cellular glass blocks over reinforced concrete. In 1990, much of this floor was replaced with 25 feet (7.6 m) square slabs. The walls and door are insulated with 13 inches (33 cm) of glass-wool board sheathed in galvanized steel. To seal the doors, they are pulled against foam rubber
seals. The ceiling insulation is on a corrugated steel deck, which is suspended from the roof trusses by chains.
refrigerant. Liquid refrigerant is held in a low-pressure surge tank. The pressure in this tank is maintained at the saturation pressure for the desired temperature for the cooling coils. Vapor from this tank is compressed to a gage pressure of 20 psi (138 kPa) by the first-stage compressor. The compressed vapor is expanded into an intermediate, desuperheater tank. Liquid condensed in this expansion is drained back the to the surge tank. The remaining vapor is compressed in a high-stage compressor to a gage pressure of about 150 psi (1 MPa). Heat is transferred from the hot vapor to cooling water. Any condensed liquid is returned to the intermediate tank, the surge tank, or the supply tank. Liquid refrigerant from the surge tank is pumped through the cooling coils at sufficient pressure to avoid vaporization. Warmed liquid is returned to the surge tank. As its pressure is reduced, a portion of this liquid will flash into vapor.
There are three such refrigeration systems. Each low-stage compressor is powered by a 1000 hp motor and each high-stage compressor is powered by a 1250 hp motor. The system was built by York Corporation. The original motors were Allis-Chalmers
induction motors. They have been replaced by variable frequency, synchronous motor
s manufactured by EMICC that operate between 350 and 1800 rpm. Recent efforts have been made to change from ozone-depleting refrigerants
.
For engine tests, there is need for makeup air. The system originally could cool 200 pounds (91 kg) per second of humid air. In 1966, this was increased to 450 pounds (204 kg) per second. Air is also cooled by a two-stage heat exchanger. The first stage uses 110000 gallons (416 m³) of 20% calcium chloride
brine pre-cooled to 24 °F (-4 °C). The second stage uses 137500 gallons (520 m³) of methylene chloride pre-cooled to -97 °F. This can cool 450 pounds (204 kg) per second of humid air from 80 °F (27 °C) to -65 °F for 40 minutes.
Eglin Air Force Base
Eglin Air Force Base is a United States Air Force base located approximately 3 miles southwest of Valparaiso, Florida in Okaloosa County....
, Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
. The laboratory is part of the 46th Test Wing
46th Test Wing
The 46th Test Wing is a wing of the United States Air Force based out of Eglin Air Force Base, Florida. The wing operates as tenant unit at Holloman AFB, NM.-Mission:...
. In addition to Air Force testing, it can be used by other US government agencies and private industry.
On October 6, 1997, it was added to the U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
National Register of Historic Places
National Register of Historic Places
The National Register of Historic Places is the United States government's official list of districts, sites, buildings, structures, and objects deemed worthy of preservation...
. The laboratory was named a National Historic Mechanical Engineering Landmark by the American Society of Mechanical Engineers
American Society of Mechanical Engineers
The American Society of Mechanical Engineers is a professional body, specifically an engineering society, focused on mechanical engineering....
in 1987.
History
In 1940, the US Army Air ForceUnited States Army Air Forces
The United States Army Air Forces was the military aviation arm of the United States of America during and immediately after World War II, and the direct predecessor of the United States Air Force....
designated Ladd Field in Fairbanks, Alaska
Fairbanks, Alaska
Fairbanks is a home rule city in and the borough seat of the Fairbanks North Star Borough in the U.S. state of Alaska.Fairbanks is the largest city in the Interior region of Alaska, and second largest in the state behind Anchorage...
as a cold-weather testing facility. Because sufficiently cold weather was not predictable and often of short duration, Ashley McKinley suggested a refrigerated airplane hangar
Hangar
A hangar is a closed structure to hold aircraft or spacecraft in protective storage. Most hangars are built of metal, but other materials such as wood and concrete are also sometimes used...
be built. The facilities were constructed at Eglin Field
Eglin Air Force Base
Eglin Air Force Base is a United States Air Force base located approximately 3 miles southwest of Valparaiso, Florida in Okaloosa County....
.
The first tests started in May 1947. Airplanes that were tested included the B-29 Superfortress
B-29 Superfortress
The B-29 Superfortress is a four-engine propeller-driven heavy bomber designed by Boeing that was flown primarily by the United States Air Forces in late-World War II and through the Korean War. The B-29 was one of the largest aircraft to see service during World War II...
, C-82 Packet
C-82 Packet
The C-82 Packet was a twin-engine, twin-boom cargo aircraft designed and built by Fairchild Aircraft. It was used briefly by the United States Army Air Forces and United States Navy following World War II.-Design and development:...
, P-47 Thunderbolt
P-47 Thunderbolt
Republic Aviation's P-47 Thunderbolt, also known as the "Jug", was the largest, heaviest, and most expensive fighter aircraft in history to be powered by a single reciprocating engine. It was heavily armed with eight .50-caliber machine guns, four per wing. When fully loaded, the P-47 weighed up to...
, P-51 Mustang
P-51 Mustang
The North American Aviation P-51 Mustang was an American long-range, single-seat fighter and fighter-bomber used during World War II, the Korean War and in several other conflicts...
, P-80 Shooting Star
P-80 Shooting Star
The Lockheed P-80 Shooting Star was the first jet fighter used operationally by the United States Army Air Forces. Designed in 1943 as a response to the German Messerschmitt Me-262 jet fighter, and delivered in just 143 days from the start of the design process, production models were flying but...
, and the Sikorsky H-5
Sikorsky H-5
The Sikorsky H-5, is a helicopter built by Sikorsky Aircraft Corporation, formerly used by the United States Air Force, and its predecessor, the United States Army Air Forces, as well as the United States Navy and United States Coast Guard The Sikorsky H-5, (aka R-5, S-51, HO3S-1, or Horse) (R-5...
D helicopter. More recently, it has tested the C-5 Galaxy
C-5 Galaxy
The Lockheed C-5 Galaxy is a large military transport aircraft built by Lockheed. It provides the United States Air Force with a heavy intercontinental-range strategic airlift capability, one that can carry outsize and oversize cargos, including all air-certifiable cargo. The Galaxy has many...
, the F-117, the F-22 and the Boeing 787
Boeing 787
The Boeing 787 Dreamliner is a long-range, mid-size wide-body, twin-engine jet airliner developed by Boeing Commercial Airplanes. It seats 210 to 290 passengers, depending on the variant. Boeing states that it is the company's most fuel-efficient airliner and the world's first major airliner to use...
.
On 12 June 1971, the hangar was dedicated at the McKinley Climatic Hangar in honor of Col. Ashley McKinley, who suggested the facility and served at Eglin during its construction.
Buildings
The Building 440 is an insulated, refrigerated hangar. There is an office and instrumentation building, a cold-weather engine test cell, the refrigeration system, mechanical-draft cooling towers, and a steam-heating plant.The main chamber is 252 feet (77 m) wide, 201 feet (61 m) deep, and 70 feet (21 m) tall at the center of the hangar. It was constructed to hold aircraft as large a B-29, its size also fitting the larger Convair B-36 Peacemaker. In 1968, a 60 feet (18 m) by 85 feet (26 m) extension was added. It now has 55000 ft2 working area. This allows it to test aircraft as large as a C-5A. Under hot conditions, it can achieve 165 °F (74 °C).
The All-Weather Room is 42 feet (13 m) by 22 feet (7 m). It has a temperature range from -80 °F to 170 °F (77 °C). Rainfall can be as high as 15 inches (381 mm) per hour and the wind can be as high as 60 knots (33 m/s). Snow can be made in the chamber.
The Temperature-Altitude Chamber is 13.5 feet (4.1 m) by 9.5 feet (2.9 m) with a height of 6.9 feet (2.1 m). Altitudes up to 80000 feet (24 km) can be simulated. The temperature range is -80 °F to 140 °F (60 °C).
The engine test cell was originally used for aircraft engines. It was about 130 feet (40 m) by 30 feet (9 m) with a height of 25 feet (8 m). It is now called the Equipment Test Chamber and is used mainly for tank
Tank
A tank is a tracked, armoured fighting vehicle designed for front-line combat which combines operational mobility, tactical offensive, and defensive capabilities...
s, trucks, and other equipment. The original building had small tests rooms for desert, hot, marine, and jungle conditions. These have been eliminated.
The original floor of the building was constructed of reinforced-concrete
Reinforced concrete
Reinforced concrete is concrete in which reinforcement bars , reinforcement grids, plates or fibers have been incorporated to strengthen the concrete in tension. It was invented by French gardener Joseph Monier in 1849 and patented in 1867. The term Ferro Concrete refers only to concrete that is...
slabs that were 12 inches (30 cm) thick and 12.5 feet (3.8 m) square. The slabs rested on 13 inches (33 cm) of cellular glass blocks over reinforced concrete. In 1990, much of this floor was replaced with 25 feet (7.6 m) square slabs. The walls and door are insulated with 13 inches (33 cm) of glass-wool board sheathed in galvanized steel. To seal the doors, they are pulled against foam rubber
Foam rubber
Foam rubber refers to rubber that has been manufactured with a foaming agent to create an air-filled matrix structure. Commercial foam rubbers are generally either polyurethane foam or natural foam rubber latex. Latex foam rubber, used in mattresses, is well-known for its endurance.-See also:*...
seals. The ceiling insulation is on a corrugated steel deck, which is suspended from the roof trusses by chains.
Refrigeration system
The original coolant was R-12Dichlorodifluoromethane
Dichlorodifluoromethane , is a colorless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane , used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other...
refrigerant. Liquid refrigerant is held in a low-pressure surge tank. The pressure in this tank is maintained at the saturation pressure for the desired temperature for the cooling coils. Vapor from this tank is compressed to a gage pressure of 20 psi (138 kPa) by the first-stage compressor. The compressed vapor is expanded into an intermediate, desuperheater tank. Liquid condensed in this expansion is drained back the to the surge tank. The remaining vapor is compressed in a high-stage compressor to a gage pressure of about 150 psi (1 MPa). Heat is transferred from the hot vapor to cooling water. Any condensed liquid is returned to the intermediate tank, the surge tank, or the supply tank. Liquid refrigerant from the surge tank is pumped through the cooling coils at sufficient pressure to avoid vaporization. Warmed liquid is returned to the surge tank. As its pressure is reduced, a portion of this liquid will flash into vapor.
There are three such refrigeration systems. Each low-stage compressor is powered by a 1000 hp motor and each high-stage compressor is powered by a 1250 hp motor. The system was built by York Corporation. The original motors were Allis-Chalmers
Allis-Chalmers
The Allis-Chalmers Manufacturing Co. of West Allis, Wisconsin, is an American company known for its past as a manufacturer with diverse interests, perhaps most famous for their bright Persian Orange farm tractors...
induction motors. They have been replaced by variable frequency, synchronous motor
Synchronous motor
A synchronous electric motor is an AC motor distinguished by a rotor spinning with coils passing magnets at the same rate as the power supply frequency and resulting rotating magnetic field which drives it....
s manufactured by EMICC that operate between 350 and 1800 rpm. Recent efforts have been made to change from ozone-depleting refrigerants
Ozone depletion
Ozone depletion describes two distinct but related phenomena observed since the late 1970s: a steady decline of about 4% per decade in the total volume of ozone in Earth's stratosphere , and a much larger springtime decrease in stratospheric ozone over Earth's polar regions. The latter phenomenon...
.
For engine tests, there is need for makeup air. The system originally could cool 200 pounds (91 kg) per second of humid air. In 1966, this was increased to 450 pounds (204 kg) per second. Air is also cooled by a two-stage heat exchanger. The first stage uses 110000 gallons (416 m³) of 20% calcium chloride
Calcium chloride
Calcium chloride, CaCl2, is a salt of calcium and chlorine. It behaves as a typical ionic halide, and is solid at room temperature. Common applications include brine for refrigeration plants, ice and dust control on roads, and desiccation...
brine pre-cooled to 24 °F (-4 °C). The second stage uses 137500 gallons (520 m³) of methylene chloride pre-cooled to -97 °F. This can cool 450 pounds (204 kg) per second of humid air from 80 °F (27 °C) to -65 °F for 40 minutes.