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75-585: The Mohawk began as a joint Army-Marine program through the then-Navy Bureau of Aeronautics (BuAer), for an observation/attack plane that would outperform the Cessna L-19 Bird Dog . In June 1956, the Army issued Type Specification TS145, which called for the development and procurement of a two-seat, twin turboprop aircraft designed to operate from small, unimproved fields under all weather conditions. It would be faster, with greater firepower, and heavier armour than

150-525: A MiG-17 “Fresco” fighter jet with his XM14 .50 in. (12.7 mm) caliber gun pods as well as two M159 unguided rocket pods, becoming the only Army Aviator to ever down a MiG. Due to the Key West Agreement , the Army tried to keep the shootdown a secret for fear that it would allow the USAF to transfer Mohawks to its inventory. Lee's kill was finally formally recognized by the Army in 2007. The Army also used

225-505: A SLAR system, until the U.S. Air Force's Northrop Grumman E-8 Joint STARS (Joint Surveillance Target Attack Radar System) aircraft became fully operational. As of 2011, Alliant Techsystems partnered with the Broadbay Group and Mohawk Technologies of Florida in a venture to return an armed, modernized version of the OV-1D to operational use as a counter-insurgency aircraft . A demonstrator

300-426: A central point, or perhaps to a distributed system in which all participate, such that the information can be correlated and a location computed. Modern SIGINT systems, therefore, have substantial communications among intercept platforms. Even if some platforms are clandestine, there is still a broadcast of information telling them where and how to look for signals. A United States targeting system under development in

375-472: A confirmation, followed by observation of artillery fire, may identify an automated counterbattery fire system. A radio signal that triggers navigational beacons could be a radio landing aid for an airstrip or helicopter pad that is intended to be low-profile. Patterns do emerge. A radio signal with certain characteristics, originating from a fixed headquarters, may strongly suggest that a particular unit will soon move out of its regular base. The contents of

450-458: A different ECCM way to identify frequencies not being jammed or not in use. The earliest, and still common, means of direction finding is to use directional antennas as goniometers , so that a line can be drawn from the receiver through the position of the signal of interest. (See HF/DF .) Knowing the compass bearing, from a single point, to the transmitter does not locate it. Where the bearings from multiple points, using goniometry, are plotted on

525-630: A lower level, German cryptanalysis, direction finding, and traffic analysis were vital to Rommel's early successes in the Western Desert Campaign until British forces tightened their communications discipline and Australian raiders destroyed his principle SIGINT Company. The United States Department of Defense has defined the term "signals intelligence" as: Being a broad field, SIGINT has many sub-disciplines. The two main ones are communications intelligence (COMINT) and electronic intelligence (ELINT). A collection system has to know to look for

600-407: A map, the transmitter will be located at the point where the bearings intersect. This is the simplest case; a target may try to confuse listeners by having multiple transmitters, giving the same signal from different locations, switching on and off in a pattern known to their user but apparently random to the listener. Individual directional antennas have to be manually or automatically turned to find

675-648: A particular signal. "System", in this context, has several nuances. Targeting is the process of developing collection requirements : First, atmospheric conditions, sunspots , the target's transmission schedule and antenna characteristics, and other factors create uncertainty that a given signal intercept sensor will be able to "hear" the signal of interest, even with a geographically fixed target and an opponent making no attempt to evade interception. Basic countermeasures against interception include frequent changing of radio frequency , polarization , and other transmission characteristics. An intercept aircraft could not get off

750-515: A peace-time codebreaking agency should be created. The Government Code and Cypher School (GC&CS) was the first peace-time codebreaking agency, with a public function "to advise as to the security of codes and cyphers used by all Government departments and to assist in their provision", but also with a secret directive to "study the methods of cypher communications used by foreign powers". GC&CS officially formed on 1 November 1919, and produced its first decrypt on 19 October. By 1940, GC&CS

825-516: A precise picture of the normal operation of the High Seas Fleet , to infer from the routes they chose where defensive minefields had been placed and where it was safe for ships to operate. Whenever a change to the normal pattern was seen, it immediately signalled that some operation was about to take place, and a warning could be given. Detailed information about submarine movements was also available. The use of radio-receiving equipment to pinpoint

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900-401: A radar is operating. Once the radar is known to be in the area, the next step is to find its location. If operators know the probable frequencies of transmissions of interest, they may use a set of receivers, preset to the frequencies of interest. These are the frequency (horizontal axis) versus power (vertical axis) produced at the transmitter, before any filtering of signals that do not add to

975-401: A safe distance from the user of the transmitter. When locations are known, usage patterns may emerge, from which inferences may be drawn. Traffic analysis is the discipline of drawing patterns from information flow among a set of senders and receivers, whether those senders and receivers are designated by location determined through direction finding , by addressee and sender identifications in

1050-404: A sensor is unique. MASINT then becomes more informative, as individual transmitters and antennas may have unique side lobes, unintentional radiation, pulse timing, etc. Network build-up , or analysis of emitters (communication transmitters) in a target region over a sufficient period of time, enables creation of the communications flows of a battlefield. COMINT ( com munications int elligence)

1125-426: A tactical SIGINT requirement, whereas the larger aircraft tend to be assigned strategic/national missions. Before the detailed process of targeting begins, someone has to decide there is a value in collecting information about something. While it would be possible to direct signals intelligence collection at a major sports event, the systems would capture a great deal of noise, news signals, and perhaps announcements in

1200-475: A tank battalion or tank-heavy task force. Another set of transmitters might identify the logistic net for that same unit. An inventory of ELINT sources might identify the medium - and long-range counter-artillery radars in a given area. Signals intelligence units will identify changes in the EOB, which might indicate enemy unit movement, changes in command relationships, and increases or decreases in capability. Using

1275-411: A vehicle. If these are regular reports over a period of time, they might reveal a patrol pattern. Direction-finding and radio frequency MASINT could help confirm that the traffic is not deception. The EOB buildup process is divided as following: Separation of the intercepted spectrum and the signals intercepted from each sensor must take place in an extremely small period of time, in order to separate

1350-572: Is Amplitude comparison . An alternative to tunable directional antennas or large omnidirectional arrays such as the Wullenweber is to measure the time of arrival of the signal at multiple points, using GPS or a similar method to have precise time synchronization. Receivers can be on ground stations, ships, aircraft, or satellites, giving great flexibility. A more accurate approach is Interferometer. Modern anti-radiation missiles can home in on and attack transmitters; military antennas are rarely

1425-417: Is a sub-category of signals intelligence that engages in dealing with messages or voice information derived from the interception of foreign communications. COMINT is commonly referred to as SIGINT, which can cause confusion when talking about the broader intelligence disciplines. The US Joint Chiefs of Staff defines it as "Technical information and intelligence derived from foreign communications by other than

1500-415: Is acquired by a given country. Knowledge of physics and electronic engineering further narrows the problem of what types of equipment might be in use. An intelligence aircraft flying well outside the borders of another country will listen for long-range search radars, not short-range fire control radars that would be used by a mobile air defense. Soldiers scouting the front lines of another army know that

1575-539: Is in the general area of the signal. The owner of the transmitter can assume someone is listening, so might set up tank radios in an area where he wants the other side to believe he has actual tanks. As part of Operation Quicksilver , part of the deception plan for the invasion of Europe at the Battle of Normandy , radio transmissions simulated the headquarters and subordinate units of the fictitious First United States Army Group (FUSAG), commanded by George S. Patton , to make

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1650-506: Is usually encrypted , signals intelligence may necessarily involve cryptanalysis (to decipher the messages). Traffic analysis —the study of who is signaling to whom and in what quantity—is also used to integrate information, and it may complement cryptanalysis. Electronic interceptions appeared as early as 1900, during the Boer War of 1899–1902. The British Royal Navy had installed wireless sets produced by Marconi on board their ships in

1725-500: The Admiralty ; Room 40 . An interception service known as 'Y' service , together with the post office and Marconi stations, grew rapidly to the point where the British could intercept almost all official German messages. The German fleet was in the habit each day of wirelessing the exact position of each ship and giving regular position reports when at sea. It was possible to build up

1800-521: The Battle of Jutland as the British fleet was sent out to intercept them. The direction-finding capability allowed for the tracking and location of German ships, submarines, and Zeppelins . The system was so successful that by the end of the war, over 80 million words, comprising the totality of German wireless transmission over the course of the war, had been intercepted by the operators of the Y-stations and decrypted. However, its most astonishing success

1875-695: The Korean Demilitarized Zone . Germany and France showed early interest in the Mohawk, and Grumman actually signed a license production agreement with the French manufacturer Breguet Aviation in exchange for American rights to the Atlantic maritime patrol aircraft. The very nature of the joint Army/Marine program had forced design compromises, such as ejection seats , that made the aircraft expensive and, sometimes, an openly resisted item in Army budgets. Orders for

1950-692: The Russian Army ’s advance early in World War I and led to their disastrous defeat by the Germans under Ludendorff and Hindenburg at the Battle of Tannenberg . In 1918, French intercept personnel captured a message written in the new ADFGVX cipher , which was cryptanalyzed by Georges Painvin . This gave the Allies advance warning of the German 1918 Spring Offensive . The British in particular, built up great expertise in

2025-753: The 1840s, was replaced with the "Systems Commands" (SYSCOMs). BuWeps was replaced with the current Naval Air Systems Command (NAVAIR). [REDACTED]  This article incorporates public domain material from websites or documents of the Naval History and Heritage Command . Signals intelligence#ELINT Signals intelligence ( SIGINT ) is the act and field of intelligence-gathering by interception of signals , whether communications between people ( communications intelligence —abbreviated to COMINT ) or from electronic signals not directly used in communication ( electronic intelligence —abbreviated to ELINT ). As classified and sensitive information

2100-588: The 641st Military Intelligence Battalion (CEWI)(Aerial Exploitation). U.S. Army OV-1s were retired from Europe in 1992, from South Korea in September 1996, and finally in the United States in 1996, superseded by newer systems, newer aircraft, and the evolution of reconnaissance satellites . The OV-1 was primarily replaced by the EO-5C, a militarized version of the de Havilland Canada Dash 7 turboprop airliner equipped with

2175-514: The Bird Dog, which had proved vulnerable during the Korean War . The Mohawk's mission would include observation, artillery spotting , air control, emergency resupply, naval target spotting, liaison, and radiological monitoring. The Navy specified that the aircraft must be capable of operating from small "jeep" escort carriers . The DoD selected Grumman Aircraft Corporation's G-134 design as the winner of

2250-544: The COMINT gathering method enables the intelligence officer to produce an electronic order of battle by traffic analysis and content analysis among several enemy units. For example, if the following messages were intercepted: This sequence shows that there are two units in the battlefield, unit 1 is mobile, while unit 2 is in a higher hierarchical level, perhaps a command post. One can also understand that unit 1 moved from one point to another which are distant from each 20 minutes with

2325-438: The German defense think that the main invasion was to come at another location. In like manner, fake radio transmissions from Japanese aircraft carriers, before the Battle of Pearl Harbor , were made from Japanese local waters, while the attacking ships moved under strict radio silence. Traffic analysis need not focus on human communications. For example, a sequence of a radar signal, followed by an exchange of targeting data and

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2400-552: The Mohawk was to prove a significant advance in both peace and war. The Side-Looking Airborne Radar (SLAR) could look through foliage and map terrain, presenting the observer with a film image of the earth below only minutes after the area was scanned. In military operations, the image was split in two parts, one showing fixed terrain features, the other spotting moving targets. The prototype ( YAO-1AF ) first flew on April 14, 1959. The OV-1 entered production in October 1959. In mid-1961,

2475-748: The OV-1 stopped in Fiscal 1964, and the controversy in the Pentagon over the armed Mohawk peaked with a 1965 directive that prohibited the Army from operating armed fixed-wing aircraft (See the Johnson-McConnell agreement of 1966 ). Operational success in Vietnam led to additional Mohawk orders in 1966, and by 1968, five surveillance companies were operating in Southeast Asia. The last of the Mohawk versions to enter production

2550-581: The Russian fleet prepared for conflict with Japan in 1904, the British ship HMS Diana stationed in the Suez Canal intercepted Russian naval wireless signals being sent out for the mobilization of the fleet, for the first time in history. Over the course of the First World War , a new method of signals intelligence reached maturity. Russia’s failure to properly protect its communications fatally compromised

2625-745: The USN to establish naval aviation units in the summer of 1911. The purchase of the first naval aircraft in May 1911 and passage of naval appropriations act in August 1916 lead to the establishment of the Naval Reserve Flying Corps , which would train and deploy air corps for World War I . Congress established BuAer in 1921 in order to create a single organizational home for naval aviation. Prior to 1921, cognizance for aviation had been divided among various Navy bureaus and other organizations. The first Chief of BuAer

2700-453: The actual information is at 800 kHz and 1.2 MHz. Real-world transmitters and receivers usually are directional. In the figure to the left, assume that each display is connected to a spectrum analyzer connected to a directional antenna aimed in the indicated direction. Spread-spectrum communications is an electronic counter-countermeasures (ECCM) technique to defeat looking for particular frequencies. Spectrum analysis can be used in

2775-676: The aircraft during Operation Desert Storm . Starting in 1972, the Army National Guard (ARNG) began to receive the Mohawk, with the ARNG eventually operating thirteen OV-1Bs, twenty-four OV-1Cs, and sixteen OV-1Ds serving with three aviation units in Georgia and Oregon. The Oregon Army National Guard Unit operating the Mohawk was located at McNary Field in Oregon, initially as the 1042nd Military Intelligence Company (Aerial Surveillance), then reflagged as

2850-563: The armament capability of the Mohawk and tried to get it removed, while the Marines did not want the Army's sophisticated sensors. However the Navy then opted to spend the allocated budget on a fleet oil tanker instead, so the Marines had to drop out of the program in September 1957. The Army continued with armed Mohawks and developed cargo pods that could be dropped from underwing hard points to resupply troops in emergencies. The radar imaging capability of

2925-492: The broader organizational order of battle . EOB covers both COMINT and ELINT. The Defense Intelligence Agency maintains an EOB by location. The Joint Spectrum Center (JSC) of the Defense Information Systems Agency supplements this location database with five more technical databases: For example, several voice transmitters might be identified as the command net (i.e., top commander and direct reports) in

3000-552: The cognizance of the Navy's Bureau of Ordnance (BuOrd). The USN's first attempt for naval aviation began in 1908 when it conducted observations of the Wright Brothers aircraft at Fort Myer . The first test of an aircraft from naval vessel was in 1910 when a Curtiss Model D flown by Eugene Burton Ely took off from the USS Birmingham (CL-2) and again on USS Pennsylvania (ACR-4) in early 1911. These tests were enough for

3075-515: The competition in 1957. Marine requirements contributed an unusual feature to the design. As originally proposed, the OF-1 could be fitted with water skis that would allow the aircraft to land at sea and taxi to island beaches at 20 knots (37 km/h). Since the Marines were authorized to operate fixed-wing aircraft in the close air support (CAS) role, the mockup also featured underwing pylons for rockets, bombs, and other stores. The Air Force did not like

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3150-446: The decision to target is made, the various interception points need to cooperate, since resources are limited. Knowing what interception equipment to use becomes easier when a target country buys its radars and radios from known manufacturers, or is given them as military aid . National intelligence services keep libraries of devices manufactured by their own country and others, and then use a variety of techniques to learn what equipment

3225-469: The different signals to different transmitters in the battlefield. The complexity of the separation process depends on the complexity of the transmission methods (e.g., hopping or time-division multiple access (TDMA)). By gathering and clustering data from each sensor, the measurements of the direction of signals can be optimized and get much more accurate than the basic measurements of a standard direction finding sensor. By calculating larger samples of

3300-453: The first Mohawks to serve with U.S. forces overseas were delivered to the 7th Army at Sandhofen Airfield near Mannheim, Germany. Before its formal acceptance, the camera-carrying AO-1AF was flown by Ralph Donnell on a tour of 29 European airfields to display it to the U.S. Army field commanders and potential European customers. In addition to their Vietnam and European service, SLAR-equipped Mohawks began operational missions in 1963 patrolling

3375-625: The forefront of American military strength. A talented administrator, Moffett ensured the continued independence of naval aviation during the 1920s, when Army Brig. Gen. Billy Mitchell and others sought to merge all U.S. military aviation into a single, independent air force. Upon Moffett's death, he was succeeded as Chief of the Bureau by Rear Admiral Ernest J. King , a future Fleet Admiral and Chief of Naval Operations during World War II . Other important bureau chiefs included Rear Admiral John S. McCain Sr. ,

3450-500: The fronts, that we won the war!" Supreme Allied Commander, Dwight D. Eisenhower , at the end of the war, described Ultra as having been "decisive" to Allied victory. Official historian of British Intelligence in World War II Sir Harry Hinsley argued that Ultra shortened the war "by not less than two years and probably by four years"; and that, in the absence of Ultra, it is uncertain how the war would have ended. At

3525-614: The grandfather of U.S. Senator John S. McCain III (R-Ariz.). During the 1930s, BuAer presided over rapid technological change in naval aircraft. The bureau's policy was to limit its own production, in order to support the civilian aircraft industry. BuAer used the Naval Aircraft Factory in Philadelphia , Pennsylvania , as a facility for building small numbers of prototype aircraft. World War II brought immense changes as well. BuAer

3600-420: The ground if it had to carry antennas and receivers for every possible frequency and signal type to deal with such countermeasures. Second, locating the transmitter's position is usually part of SIGINT. Triangulation and more sophisticated radio location techniques, such as time of arrival methods, require multiple receiving points at different locations. These receivers send location-relevant information to

3675-448: The information being transmitted. Received energy on a particular frequency may start a recorder, and alert a human to listen to the signals if they are intelligible (i.e., COMINT). If the frequency is not known, the operators may look for power on primary or sideband frequencies using a spectrum analyzer . Information from the spectrum analyzer is then used to tune receivers to signals of interest. For example, in this simplified spectrum,

3750-527: The late 1890s, and the British Army used some limited wireless signalling. The Boers captured some wireless sets and used them to make vital transmissions. Since the British were the only people transmitting at the time, the British did not need special interpretation of the signals that they were. The birth of signals intelligence in a modern sense dates from the Russo-Japanese War of 1904–1905. As

3825-530: The late 1990s, PSTS, constantly sends out information that helps the interceptors properly aim their antennas and tune their receivers. Larger intercept aircraft, such as the EP-3 or RC-135 , have the on-board capability to do some target analysis and planning, but others, such as the RC-12 GUARDRAIL , are completely under ground direction. GUARDRAIL aircraft are fairly small and usually work in units of three to cover

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3900-465: The late 20th century's Unmanned Aerial Vehicles ); BuAer considered these to be aircraft, while BuOrd saw them as guided missiles. To fix the problem, in 1959 the Navy merged BuAer and BuOrd to create the Bureau of Naval Weapons (BuWeps). This was only a temporary solution, however, and in 1966 the Navy undertook a wholesale revision of its material organization. The bureau system , which had existed since

3975-560: The location of any single transmitter was also developed during the war. Captain H.J. Round , working for Marconi , began carrying out experiments with direction-finding radio equipment for the army in France in 1915. By May 1915, the Admiralty was able to track German submarines crossing the North Sea. Some of these stations also acted as 'Y' stations to collect German messages, but a new section

4050-564: The message need not be known to infer the movement. There is an art as well as science of traffic analysis. Expert analysts develop a sense for what is real and what is deceptive. Harry Kidder , for example, was one of the star cryptanalysts of World War II, a star hidden behind the secret curtain of SIGINT. Generating an electronic order of battle (EOB) requires identifying SIGINT emitters in an area of interest, determining their geographic location or range of mobility, characterizing their signals, and, where possible, determining their role in

4125-410: The message, or even MASINT techniques for "fingerprinting" transmitters or operators. Message content other than the sender and receiver is not necessary to do traffic analysis, although more information can be helpful. For example, if a certain type of radio is known to be used only by tank units, even if the position is not precisely determined by direction finding, it may be assumed that a tank unit

4200-492: The newly emerging field of signals intelligence and codebreaking (synonymous with cryptanalysis). On the declaration of war, Britain cut all German undersea cables. This forced the Germans to communicate exclusively via either (A) a telegraph line that connected through the British network and thus could be tapped; or (B) through radio which the British could then intercept. Rear Admiral Henry Oliver appointed Sir Alfred Ewing to establish an interception and decryption service at

4275-461: The other side will be using radios that must be portable and not have huge antennas. Even if a signal is human communications (e.g., a radio), the intelligence collection specialists have to know it exists. If the targeting function described above learns that a country has a radar that operates in a certain frequency range, the first step is to use a sensitive receiver, with one or more antennas that listen in every direction, to find an area where such

4350-417: The sensor's output data in near real-time, together with historical information of signals, better results are achieved. Data fusion correlates data samples from different frequencies from the same sensor, "same" being confirmed by direction finding or radiofrequency MASINT. If an emitter is mobile, direction finding, other than discovering a repetitive pattern of movement, is of limited value in determining if

4425-503: The signal direction, which may be too slow when the signal is of short duration. One alternative is the Wullenweber array technique. In this method, several concentric rings of antenna elements simultaneously receive the signal, so that the best bearing will ideally be clearly on a single antenna or a small set. Wullenweber arrays for high-frequency signals are enormous, referred to as "elephant cages" by their users. A more advance approach

4500-451: The stadium. If, however, an anti-terrorist organization believed that a small group would be trying to coordinate their efforts using short-range unlicensed radios at the event, SIGINT targeting of radios of that type would be reasonable. Targeting would not know where in the stadium the radios might be located or the exact frequency they are using; those are the functions of subsequent steps such as signal detection and direction finding. Once

4575-500: The story of Operation SALAM , László Almásy 's mission across the desert behind Allied lines in 1942. Prior to the Normandy landings on D-Day in June 1944, the Allies knew the locations of all but two of Germany's fifty-eight Western Front divisions. Winston Churchill was reported to have told King George VI : "It is thanks to the secret weapon of General Menzies , put into use on all

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4650-549: The whole of the British forces in World War II came under the code name " Ultra ", managed from Government Code and Cypher School at Bletchley Park . Properly used, the German Enigma and Lorenz ciphers should have been virtually unbreakable, but flaws in German cryptographic procedures, and poor discipline among the personnel carrying them out, created vulnerabilities which made Bletchley's attacks feasible. Bletchley's work

4725-700: The years, the mission and the aircraft underwent many changes and roughly 380 were built over all variants. Mohawk variants included the JOV-1 [armed reconnaissance], OV-1A, [visual and photographic], OV-1B [visual, photographic, and side-looking radar (SLAR) pod], the OV-1C [visual, photographic, and infrared], and the OV-1D (SLAR pod and bigger wings), OV-1E [enlarged fuselage for more sensor operators or cargo], EV-1E [special electronic intelligence installation] and RV-1E [advanced ELINT reconnaissance]. A four-engined Model 134E with tiltwings and tail ducted fan for control for VTOL

4800-415: Was Rear Admiral William A. Moffett (1869–1933), a Medal of Honor recipient and battleship commander who had long supported the development of naval aviation. He served as bureau chief from 1921 until his death in 1933, in the crash of the airship USS Akron (ZRS-4) . Working closely with RADM Moffett, CAPT Henry C. Mustin (1874–1923) served as BuAer's first Assistant Chief helping lead naval aviation to

4875-407: Was based on a public domain article from Greg Goebel's Vectorsite . Bureau of Aeronautics The Bureau of Aeronautics (BuAer) was the U.S. Navy 's material-support organization for naval aviation from 1921 to 1959. The bureau had "cognizance" ( i.e. , responsibility) for the design, procurement, and support of naval aircraft and related systems. Aerial weapons, however, were under

4950-535: Was created within Room 40 to plot the positions of ships from the directional reports. Room 40 played an important role in several naval engagements during the war, notably in detecting major German sorties into the North Sea . The battle of Dogger Bank was won in no small part due to the intercepts that allowed the Navy to position its ships in the right place. It played a vital role in subsequent naval clashes, including at

5025-709: Was destroyed and the pilot was killed. Its serial number was 68-15958. On 14 January 1981, a Grumman OV-1D Mohawk crashed and burned in a rural area near Lampasas, Texas during a maintenance test flight out of Fort Hood, Texas for engine rigging and nose gear strut replacement. The Inertial Navigation System had stretched a wire/pulled a pin at a computer connector and the pin re-locked. Pilot CW3 Sandy L. Oliphant and SSG Roger A. Meadows were killed instantly. Data from Jane's Civil and Military Aircraft Upgrades 1994–95 General characteristics Performance Aircraft of comparable role, configuration, and era Related lists The initial version of this article

5100-490: Was equipped with a FLIR Star Safire turret and a ventral, trainable M230 chain gun . The Argentine Army Aviation received twenty-three OV-1s in the 1990s. Ten were operational and the rest were used for spare parts. They became inactive and retired from use in 2015. On 1 November 2019, a Grumman OV-1D Mohawk operated by Mohawk Airshows crashed at Witham Field, Stuart, Florida , during the Stuart Air Show. The aircraft

5175-665: Was essential to defeating the U-boats in the Battle of the Atlantic , and to the British naval victories in the Battle of Cape Matapan and the Battle of North Cape . In 1941, Ultra exerted a powerful effect on the North African desert campaign against German forces under General Erwin Rommel . General Sir Claude Auchinleck wrote that were it not for Ultra, "Rommel would have certainly got through to Cairo". Ultra decrypts featured prominently in

5250-480: Was forced to expand rapidly in order to comply with the nation's defense needs. By the war's end, the bureau had developed an administrative structure that oversaw thousands of personnel, and the procurement and maintenance of tens of thousands of aircraft. In 1943, the Navy established the position of Deputy Chief of Naval Operations for Air, or DCNO(Air), a move which relieved some of BuAer's responsibility for Fleet operations. RADM McCain , now promoted to vice admiral,

5325-683: Was in decrypting the Zimmermann Telegram , a telegram from the German Foreign Office sent via Washington to its ambassador Heinrich von Eckardt in Mexico. With the importance of interception and decryption firmly established by the wartime experience, countries established permanent agencies dedicated to this task in the interwar period. In 1919, the British Cabinet's Secret Service Committee, chaired by Lord Curzon , recommended that

5400-747: Was proposed to the Army but not built. Model 134R was a tandem cockpit version offered to meet the Light Armed Reconnaissance Aircraft (LARA) requirement, but the NA300 was chosen instead becoming the OV-10 . The U.S. Army flew the OV-1 operationally in the Vietnam War , with sixty-five lost to accidents and ground fire, and one shot down by a North Vietnamese fighter. In early 1968, while flying an OV-1 over South Vietnam, U.S. Army Captain Ken Lee shot down

5475-472: Was the OV-1D with more powerful T53-L-701 engines, improved avionics, and interchangeable mission pallets that made it possible to switch the aircraft from infrared to SLAR configuration in about an hour. The first four OV-1Ds were prototypes converted from earlier production airframes, and the first flew in 1969. These were followed by 37 new-build aircraft, the last of which was delivered in December 1970. Over

5550-419: Was the first to fill the position. BuAer downsized after the war, but continued its focus on aeronautical research and development. But as naval technology became increasingly complex, it became clear that the Navy's material organization was insufficient. In particular, the Navy needed better integration of aerial weapons with naval aircraft. There was also the question of "pilotless aircraft" (the ancestors of

5625-661: Was working on the diplomatic codes and ciphers of 26 countries, tackling over 150 diplomatic cryptosystems. The US Cipher Bureau was established in 1919 and achieved some success at the Washington Naval Conference in 1921, through cryptanalysis by Herbert Yardley . Secretary of War Henry L. Stimson closed the US Cipher Bureau in 1929 with the words "Gentlemen do not read each other's mail." The use of SIGINT had even greater implications during World War II . The combined effort of intercepts and cryptanalysis for

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