Link Trainer
Encyclopedia
Flight simulator
A flight simulator is a device that artificially re-creates aircraft flight and various aspects of the flight environment. This includes the equations that govern how aircraft fly, how they react to applications of their controls and other aircraft systems, and how they react to the external...
s produced between the early 1930s and early 1950s by Ed Link
Edwin Albert Link
Edwin Albert Link was a pioneer in aviation, underwater archaeology, and ocean engineering. He is most remembered for inventing the flight simulator, commercialized in 1929, called the "Blue Box" or "Link Trainer", which started the now multi-billion dollar flight simulation industry...
, based on technology he pioneered in 1929 at his family's business in Binghamton, New York
Binghamton, New York
Binghamton is a city in the Southern Tier of New York in the United States. It is near the Pennsylvania border, in a bowl-shaped valley at the confluence of the Susquehanna and Chenango Rivers...
. These simulators became famous during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, when they were used as a key pilot training aid by almost every combatant nation.
The original Link Trainer was created in 1929 out of the need for a safe way to teach new pilots how to fly by instruments
Avionics
Avionics are electronic systems used on aircraft, artificial satellites and spacecraft.Avionic systems include communications, navigation, the display and management of multiple systems and the hundreds of systems that are fitted to aircraft to meet individual roles...
. A former organ
Organ (music)
The organ , is a keyboard instrument of one or more divisions, each played with its own keyboard operated either with the hands or with the feet. The organ is a relatively old musical instrument in the Western musical tradition, dating from the time of Ctesibius of Alexandria who is credited with...
and nickelodeon builder, Link used his knowledge of pump
Pump
A pump is a device used to move fluids, such as liquids, gases or slurries.A pump displaces a volume by physical or mechanical action. Pumps fall into three major groups: direct lift, displacement, and gravity pumps...
s, valve
Valve
A valve is a device that regulates, directs or controls the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category...
s and bellows
Bellows
A bellows is a device for delivering pressurized air in a controlled quantity to a controlled location.Basically, a bellows is a deformable container which has an outlet nozzle. When the volume of the bellows is decreased, the air escapes through the outlet...
to create a flight simulator that responded to the pilot's controls and gave an accurate reading on the included instruments. More than 500,000 US pilots were trained on Link simulators, as were pilots of nations as diverse as Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, Germany, United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, Israel
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...
, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...
and the USSR.
The Link Flight Trainer has been designated as A 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....
. The Link Company, now part of L-3 Communications, continues to make aerospace simulators.
Origins
Link's first military sales came as a result of the Air Mail scandal
Air Mail Scandal
The Air Mail scandal, also known as the Air Mail fiasco, is the name that the American press gave to the political scandal resulting from a congressional investigation of a 1930 meeting , between Postmaster General Walter Folger Brown and the executives of the top airlines, and to the disastrous...
, when the Army Air Corps
United States Army Air Corps
The United States Army Air Corps was a forerunner of the United States Air Force. Renamed from the Air Service on 2 July 1926, it was part of the United States Army and the predecessor of the United States Army Air Forces , established in 1941...
took over carriage of U.S. Air Mail. Twelve pilots were killed in a 78 day period due to their unfamiliarity with Instrument Flying Conditions
Instrument flight rules
Instrument flight rules are one of two sets of regulations governing all aspects of civil aviation aircraft operations; the other are visual flight rules ....
. The large scale loss of life prompted the Air Corps to look at a number of solutions, including Link's pilot trainer. The Air Corps was given a stark demonstration of the potential of instrument training when, in 1934, Link flew in to a meeting in conditions of fog that the Air Corps evaluation team regarded as unflyable. As a result, the Air Corps ordered the first six pilot trainers at $3,500 each.
The Link company expanded rapidly, and during World War II, the ANT-18 Basic Instrument Trainer, known to tens of thousands of fledgling pilots as the "Blue Box" (although it was painted in colors other than blue in other countries), was standard equipment at every air training school in the United States and Allied nations. During the war years, Link produced over 10,000 Blue Boxes, turning one out every 45 minutes.
Link Trainer models
Several models of Link Trainers were sold in a period ranging from 1934 through to the late 1950s. These trainers kept pace with the increased instrumentation and flight dynamics of aircraft of their period, but retained the electrical and pneumatic design fundamentals pioneered in the first Link.Trainers built from 1934 up to the early 1940s had the a color scheme that featured a bright blue fuselage and yellow wings and tail sections. These wings and tail sections had control surfaces that actually moved in response to the pilot's movement of the rudder and stick. However, many trainers built during mid to late World War II did not have these wings and tail sections due to material shortages and critical manufacturing times.
Pilot Trainer
The Pilot Trainer was Link's first model, and was an evolution of his 1929 prototype.ANT-18
The second and most prolific version of the Link Trainer was the ANT-18 (Army Navy Trainer model 18), which was in its turn, a slightly enhanced version of the model C3. This model was also produced in Canada for both the Royal Canadian Air ForceRoyal Canadian Air Force
The history of the Royal Canadian Air Force begins in 1920, when the air force was created as the Canadian Air Force . In 1924 the CAF was renamed the Royal Canadian Air Force and granted royal sanction by King George V. The RCAF existed as an independent service until 1968...
and the Royal Air Force
Royal Air Force
The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...
with a somewhat modified instrument panel, where its model designation was D2. It was used by many countries for pilot training before and during the Second World War, especially in the British Commonwealth Air Training Plan
British Commonwealth Air Training Plan
The British Commonwealth Air Training Plan , known in some countries as the Empire Air Training Scheme , was a massive, joint military aircrew training program created by the United Kingdom, Canada, Australia and New Zealand, during the Second World War...
.
The ANT-18 featured rotation through all three axes, effectively simulated all flight instruments, and modeled common conditions such as pre-stall
Stall (flight)
In fluid dynamics, a stall is a reduction in the lift coefficient generated by a foil as angle of attack increases. This occurs when the critical angle of attack of the foil is exceeded...
buffet, overspeed of the retractable undercarriage
Undercarriage
The undercarriage or landing gear in aviation, is the structure that supports an aircraft on the ground and allows it to taxi, takeoff and land...
, and spin
Spin (flight)
In aviation, a spin is an aggravated stall resulting in autorotation about the spin axis wherein the aircraft follows a corkscrew downward path. Spins can be entered intentionally or unintentionally, from any flight attitude and from practically any airspeed—all that is required is sufficient yaw...
ning. It was fitted with a removable opaque canopy, which could be used to simulate blind flying, and was particularly useful for instrument and navigation training.
ANT-18 design and construction
The ANT-18 consists of two main components.The first major component is the trainer itself. The trainer consists of a wooden box approximating the shape of a cockpit and forward fuselage section, which is connected via a universal joint
Universal joint
A universal joint, universal coupling, U joint, Cardan joint, Hardy-Spicer joint, or Hooke's joint is a joint or coupling in a rigid rod that allows the rod to 'bend' in any direction, and is commonly used in shafts that transmit rotary motion...
to a base. Inside the cockpit is a single pilot's seat, primary and secondary aircraft controls, and a full suite of flight instruments. The base contains several complicated sets of air-driven bellows to simulate movement, a vacuum pump which both drives the bellows and provides input to a number of aircraft instruments, and a device known as a Telegon Oscillator, which controls the remaining instruments.
The second major component is an external instructor's station, which consists of a large map table, a repeated display of the main flight instruments, and a moving marker known as a "crab." The crab moves across the glass surface of the map table, plotting the pilot's track. The pilot and instructor can communicate with each other via headphones and microphones.
The ANT-18 has three main sets of bellows
Bellows
A bellows is a device for delivering pressurized air in a controlled quantity to a controlled location.Basically, a bellows is a deformable container which has an outlet nozzle. When the volume of the bellows is decreased, the air escapes through the outlet...
. One set of four bellows (one under each corner of the cockpit) controls movement in the pitch and roll planes. A very complicated set of bellows at the front of the cockpit controls movement in the yaw plane. This complex set of 10 bellows, two crank shafts and various gears and pulleys comprised the turning motor. This motor could turn the entire cockpit in continuous 360 degree circles. This was possible since a series of electrical slip ring contacts in the lower base compartment, supplied electrical continuity between the cockpit and the base.
A third set simulates vibration such as stall buffet. Both the trainer and the instructor's station are powered from standard 110VAC/240VAC power outlets via a transformer
Transformer
A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field...
, with the bulk of internal wiring being low voltage. Simulator logic
Logic
In philosophy, Logic is the formal systematic study of the principles of valid inference and correct reasoning. Logic is used in most intellectual activities, but is studied primarily in the disciplines of philosophy, mathematics, semantics, and computer science...
is all analog and is based around vacuum tube
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
s.
Survivors
A number of Link Trainers are known to survive around the world. Many ANT-18 simulators survive around the world today. The USA and AustraliaAustralia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
are hot spots for survivors.
Australia
At least 22 ANT-18 trainers survive in Australia, in various states of repair. A number of these are in museums, but the majority are in the custody of the Australian Air Force CadetsAustralian Air Force Cadets
The Australian Air Force Cadets , known as the Air Training Corps until 2001, is a Federal Government funded youth organisation. The parent force of the AAFC is the Royal Australian Air Force...
, who were given them in the 1950s by the Royal Australian Air Force (RAAF)
Royal Australian Air Force
The Royal Australian Air Force is the air force branch of the Australian Defence Force. The RAAF was formed in March 1921. It continues the traditions of the Australian Flying Corps , which was formed on 22 October 1912. The RAAF has taken part in many of the 20th century's major conflicts...
. They were maintained until 1975 by the RAAF, and as a result many are still in relatively good condition, being either fully or partially operational. The number of operational ANT-18s has been boosted in recent years by the restoration of several machines.
Canada
A fully functional Link Trainer is owned and operated by the Canadian Harvard Aircraft AssociationCanadian Harvard Aircraft Association
The Canadian Harvard Aircraft Association is a non-profit charitable organization based in Tillsonburg, Ontario. It was founded with the aim of acquiring, preserving, restoring, maintaining, displaying and demonstrating the North American Harvard aircraft and other training aircraft associated...
of Tillsonburg, Ontario. Other Link Trainers are on display at the Canadian Air and Space Museum
Canadian Air and Space Museum
The Canadian Air and Space Museum is an aviation museum featuring artifacts, exhibits and stories illustrating a century of Canadian aviation heritage and achievements...
, the Western Canada Aviation Museum
Western Canada Aviation Museum
The Western Canada Aviation Museum is a museum in Winnipeg, Manitoba, Canada. It is the second largest aviation museum in Canada. The collection is housed in an original Trans-Canada Air Lines hangar dating from the 1930s....
, the Canadian War Museum
Canadian War Museum
The Canadian War Museum is Canada’s national museum of military history. Located in Ottawa, Ontario, the museum covers all facets of Canada’s military past, from the first recorded instances of death by armed violence in Canadian history several thousand years ago to the country’s most recent...
and Commonwealth Air Training Plan Museum
Commonwealth Air Training Plan Museum
The Commonwealth Air Training Plan Museum is an aviation museum located at Brandon Municipal Airport, Brandon, Manitoba. It is dedicated to the memory of the airmen from the British Commonwealth Air Training Plan, who trained at World War II air stations across Canada...
. There is also a Link Trainer on display at the North Atlantic Aviation Museum
North Atlantic Aviation Museum
The North Atlantic Aviation Museum is an aviation museum located in the town of Gander, Newfoundland and Labrador, Canada. The association to establish the museum was formed in 1985 and the museum opened to the public in 1996....
in Gander, Newfoundland, Canada; it was used in the television series Above and Beyond
Above and Beyond (mini series)
Above and Beyond is a four-hour 2006 miniseries aired by the Canadian Broadcasting Corporation on October 29 and 30. The miniseries is about the Atlantic Ferry Organization, which was tasked with delivering aircraft from North America to Europe in the early years of the Second World War. It...
(2006). Another Link Trainer is on display at the museum in Claresholm, Alberta
Claresholm, Alberta
Claresholm is a town located within southern Alberta, Canada. It is located on Highway 2, approximately northwest of the City of Lethbridge and south of the City of Calgary. The town is the seat of the Municipal District of Willow Creek No...
, where the No. 15 Service Flying Training School was situated during World War II.
United Kingdom
A number of Link Trainers are known to exist in Britain. Known survivors are located at:- Brooklands MuseumBrooklands MuseumBrooklands Museum is an independent charitable trust, established in 1987, whose aim is to conserve, protect and interpret the unique heritage of the Brooklands site. It is located south of Weybridge, Surrey and was first opened regularly in 1991 on of the original 1907 motor-racing circuit...
(ANT-18) - The Welford Museum
- No. 424 (Southampton) Squadron Air Training CorpsAir Training CorpsThe Air Training Corps , commonly known as the Air Cadets, is a cadet organisation based in the United Kingdom. It is a voluntary youth group which is part of the Air Cadet Organisation and the Royal Air Force . It is supported by the Ministry of Defence, with a regular RAF Officer, currently Air...
- No. 195 (Grimsby) Squadron Air Training CorpsAir Training CorpsThe Air Training Corps , commonly known as the Air Cadets, is a cadet organisation based in the United Kingdom. It is a voluntary youth group which is part of the Air Cadet Organisation and the Royal Air Force . It is supported by the Ministry of Defence, with a regular RAF Officer, currently Air...
which is fully operational after being restored around the turn of the millennium - No. 1349 Woking Squadron Air Training CorpsAir Training CorpsThe Air Training Corps , commonly known as the Air Cadets, is a cadet organisation based in the United Kingdom. It is a voluntary youth group which is part of the Air Cadet Organisation and the Royal Air Force . It is supported by the Ministry of Defence, with a regular RAF Officer, currently Air...
which is fully operational - No. 328 (Kingston) Squadron Air Training CorpsAir Training CorpsThe Air Training Corps , commonly known as the Air Cadets, is a cadet organisation based in the United Kingdom. It is a voluntary youth group which is part of the Air Cadet Organisation and the Royal Air Force . It is supported by the Ministry of Defence, with a regular RAF Officer, currently Air...
(ANT-18) - No. 130 (Bournemouth) Squadron Air Training CorpsAir Training CorpsThe Air Training Corps , commonly known as the Air Cadets, is a cadet organisation based in the United Kingdom. It is a voluntary youth group which is part of the Air Cadet Organisation and the Royal Air Force . It is supported by the Ministry of Defence, with a regular RAF Officer, currently Air...
- No. 1344 (Cardiff) Squadron Air Training CorpsAir Training CorpsThe Air Training Corps , commonly known as the Air Cadets, is a cadet organisation based in the United Kingdom. It is a voluntary youth group which is part of the Air Cadet Organisation and the Royal Air Force . It is supported by the Ministry of Defence, with a regular RAF Officer, currently Air...
- Wellingborough School CCF RAF Section
- Imperial War Museum DuxfordImperial War Museum DuxfordImperial War Museum Duxford is a branch of the Imperial War Museum near the village of Duxford in Cambridgeshire, England. Britain's largest aviation museum, Duxford houses the museum's large exhibits, including nearly 200 aircraft, military vehicles, artillery and minor naval vessels in seven...
- Caernarfon Airport Aviation MuseumCaernarfon AirportCaernarfon Airport is located southwest of Caernarfon, Gwynedd, Wales.Caernarfon Aerodrome has a CAA Ordinary Licence that allows flights for the public transport of passengers or for flying instruction as authorised by the licensee...
, North Wales - Brenzett Aeronautical MuseumBrenzettBrenzett is a village and civil parish in the Shepway District of Kent, England. The village lies on the Romney Marsh, three miles west of New Romney....
, Kent - Manston History ClubRAF ManstonRAF Manston was an RAF station in the north-east of Kent, at on the Isle of Thanet from 1916 until 1996. The site is now split between a commercial airport Kent International Airport and a continuing military use by the Defence Fire Training and Development Centre , following on from a long...
, Kent - Rochester Airport, Kent
- Tangmere Aviation MuseumRAF TangmereRAF Tangmere was a Royal Air Force station famous for its role in the Battle of Britain, located at Tangmere village about 3 miles east of Chichester in West Sussex, England. American RAF pilot Billy Fiske died at Tangmere and was the first American aviator to die during World War II...
, West Sussex - North East Aircraft MuseumNorth East Aircraft MuseumThe North East Aircraft Museum is a volunteer-run aviation museum situated on the site of the former RAF Usworth/Sunderland Airport, between Washington and Sunderland, England. The museum has the largest aviation collection between Yorkshire and Scotland and houses over 30 aircraft and a wide...
, Sunderland
Serbia
At least three examples are known to exist out of which Aviation Museum in Belgrade owns one and Aeroklub Valjevo, Valjevo owns one example that was still operational in the '80s, nowadays it requires new set of vacuum tubes but otherwise it is in a good state.USA
The British Flight Training School#1 Museum located on the grounds of the Terrell Municipal AirportTerrell Municipal Airport
Terrell Municipal Airport is a public access airport located within the city limits of Terrell, Texas, 1 mile SE of central Terrell.The airport has services for commercial and private aviation. Aircraft operations, including local general aviation, transient general aviation, and air taxi, average...
in Terrell, Texas
Terrell, Texas
Terrell is a city in Kaufman County, Texas, United States, and a southeastern suburb of Dallas. As of the 2000 census, the city population was 13,606...
has a complete Link Trainer assembly with attached instructor's station on display at the museum dedicated to the 2,000 Royal Air Force
Royal Air Force
The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...
Cadets were trained in Terrell from August 1941 through the end of World War II as a part of the Lend-Lease
Lend-Lease
Lend-Lease was the program under which the United States of America supplied the United Kingdom, the Soviet Union, China, Free France, and other Allied nations with materiel between 1941 and 1945. It was signed into law on March 11, 1941, a year and a half after the outbreak of war in Europe in...
Act that allowed British aviation cadets to be trained in the US by civilian aviators.
A Link trainer used to train the Tuskegee Airmen
Tuskegee Airmen
The Tuskegee Airmen is the popular name of a group of African American pilots who fought in World War II. Formally, they were the 332nd Fighter Group and the 477th Bombardment Group of the U.S. Army Air Corps....
is on display at the Museum of Aviation at Robins AFB near Warner-Robins, Ga. The National Museum of the United States Air Force
National Museum of the United States Air Force
The National Museum of the United States Air Force is the official museum of the United States Air Force located at Wright-Patterson Air Force Base northeast of Dayton, Ohio. The NMUSAF is the world's largest and oldest military aviation museum with more than 360 aircraft and missiles on display...
has a Link Trainer on display; it was the museum's "Aircraft of the Week" during the first week of 2009.
The Roberson Museum in Binghamton, New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
, contains an exhibit on Edwin Link including a Link Trainer. One Link Trainer is in Post Mills, Vermont, owned by Balloonist and collector Brian Boland of Boland Balloons and can be viewed in his flight museum at Post Mills Airport.
Another Link Trainer in working condition is on display at the Commemorative Air Force
Commemorative Air Force
The Commemorative Air Force , formerly known as the Confederate Air Force, is a Texas-based non-profit organization dedicated to preserving and showing historical aircraft at airshows primarily throughout the U.S. and Canada...
Airpower Museum in Midland, Texas. Randolph Air Force Base
Randolph Air Force Base
Randolph Air Force Base is a United States Air Force base located east-northeast of San Antonio, Texas. The base is under the jurisdiction of the 902d Mission Support Group, Air Education and Training Command ....
, Texas, home of the United States Air Force's Air Education and Training Command
Air Education and Training Command
Air Education and Training Command was established July 1, 1993, with the realignment of Air Training Command and Air University. It is one of the U.S. Air Force's ten major commands and reports to Headquarters, United States Air Force....
(AETC), also has a Link Trainer on display. Likewise a Link Trainer is displayed at the Cavanaugh Flight Museum in Addison, Texas. The Museum at Hill Air Force Base, Utah has a Link Trainer on display. The Jimmy Doolittle Air & Space Museum, located at Travis AFB in CA, exhibits a Link Trainer.
Two Link Trainers are on display at the Museum of Flight Restoration Center, Paine Field in Seattle, Washington. One is in fully functional condition with the adjoining instructors table.
A "Blue Box" is on display at the Army Aviation Museum at Fork Rucker, Alabama. It was added to their collection in 2006.
There is a Link Trainer on display at the Melbourne Airport in Melbourne, Florida.
A Link Trainer is on display in the Golden Age of Flight Gallery at the San Diego Air & Space Museum. There is a light inside so visitors can see the instrument panel. In August 2009, Edwin Link's granddaughter visited the museum and shared her stories with the volunteer docents
Museum docent
Museum docent is a title used in the United States for educators trained to further the public's understanding of the cultural and historical collections of the institution, including local and national museums, zoos, historical landmarks, and parks. In many cases, docents, in addition to their...
. One of the volunteer docents trained in a Link Trainer and shares his experiences with visitors and tours.
A complete Link Trainer assembly, including an instructor's station, is on display at the Prairie Aviation Museum in Bloomington, Illinois.
The Millville Army Air Field Museum at the Millville Airport, Millville, New Jersey owns two Link Trainers, and has one, operational, on display in the World War II Link Trainer building.
A circa 1943 Link Trainer with instructor's desk is on display at NASA's Ames Research Center, Moffett Field, Mountain View, Calif. This trainer was physically and mechanically restored to full working order in 1992. This trainer did not originally have the wings and tail assembly installed. They were often omitted on trainers made during World War II. However, a set of "paddle style" wings and tail assembly was manufactured from original Link documentation specs, and added during the restoration.
The Valiant Air Command Warbird Museum in Titusville, Florida has a Link Trainer with instructor station in its collection.
Czech republic
Aviation Museum at Kbely, Prague:http://www.planes.cz/cs/photo/1055928/link-d2-trainer-no-reg-preserved-praha-kbely-lkkb/