Misplaced Pages

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106-520: The idea of building VTOL aircraft using helicopter-like rotors at the wingtips originated in the 1930s. The first design resembling modern tiltrotors was patented by George Lehberger in May 1930, but he did not develop the concept further. In World War II , a German prototype called the Focke-Achgelis Fa 269 was developed starting in 1942, but it never flew. Two prototypes that made it to flight were

212-555: A turbofan in static or hovering conditions. Its efflux can be used for Upper Surface Blown architectures to boost the Lift Coefficient to values exceeding 8.0. United States Department of Defense The United States Department of Defense ( DoD , USDOD , or DOD ) is an executive branch department of the federal government of the United States charged with coordinating and supervising all agencies and functions of

318-626: A VTOL (helicopter) show up in Leonardo da Vinci 's sketch book. Manned VTOL aircraft, in the form of primitive helicopters, first flew in 1907, but would take until after World War Two to be perfected. In addition to helicopter development, many approaches have been tried to develop practical aircraft with vertical take-off and landing capabilities, including Henry Berliner 's 1922–1925 experimental horizontal rotor fixed wing aircraft, and Nikola Tesla 's 1928 patent, and George Lehberger's 1930 patent for relatively impractical VTOL fixed wing airplanes with

424-577: A bid for an enlarged version of the XV-15 in 1983. The Bell Boeing team received a preliminary design contract that year, which led to the Bell Boeing V-22 Osprey . Following wind tunnel and flight testing by Bell, the aircraft was then moved to NASA Dryden , which is at Edwards Air Force Base in the California High Desert. The XV-15 flight testing continued expanding its flight envelope. It

530-543: A conventional wing and tilts the whole assembly to transition between vertical and horizontal flight. A tail-sitter sits vertically on its tail for takeoff and landing, then tilts the whole aircraft forward for horizontal flight. Thrust vectoring is a technique used for jet and rocket engines, where the direction of the engine exhaust is varied. In VTOL, the exhaust can be varied between vertical and horizontal thrust. Similar to tiltrotor concept, but with turbojet or turbofan engines instead of ones with propellers. A lift jet

636-748: A followup story was part of the April 2006 issue that mentioned "the fuel-consumption and stability problems that plagued earlier plane/copter." Retired from the British Royal Navy in 2006, the Indian Navy continued to operate Sea Harriers until 2016, mainly from its aircraft carrier INS  Viraat . The latest version of the Harrier, the BAE Harrier II , was retired in December 2010 after being operated by

742-504: A helicopter, then transitions to fixed-wing lift in forward flight. Examples of this include the Bell Boeing V-22 Osprey A tiltrotor or proprotor tilts its propellers or rotors vertically for VTOL and then tilts them forwards for horizontal wing-borne flight, while the main wing remains fixed in place. Similar to tiltrotor concept, but with ducted fans . As it can be seen in the Bell X-22 . A tiltwing has its propellers or rotors fixed to

848-816: A helicopter-to-aircraft transition in flight to within ten degrees of true horizontal aircraft flight. The Model 2 was developed and flew shortly afterward, but it did not fly much beyond hover tests. The United States Air Force withdrew funding in favor of the Bell XV-3 . The Bell XV-3 was first flown in 1955. Like its predecessors, the XV-3 had the engines in the fuselage and driveshafts transferring power out to tilting wingtip rotor assemblies. Other rotor concepts, such as slowed rotors , stopped rotors, folding rotors, and variable-diameter rotors, were investigated for subsequent designs, but Bell engineers Kenneth Wernicke and Bob Lichten deemed them unfeasible compared to experience with

954-439: A helicopter. The rotors would become stationary in mid-flight, and function as wings, providing lift in addition to the static wings. Boeing X-50 is a Canard Rotor/Wing prototype that utilizes a similar concept. A different British VTOL project was the gyrodyne , where a rotor is powered during take-off and landing but which then freewheels during flight, with separate propulsion engines providing forward thrust. Starting with

1060-578: A major design concept advance: instead of engines in the fuselage, the XV-15 moved the engines out to the rotating wingtip pods, directly coupled to the rotors. The normal path for power was directly from the engine into a speed-reduction gearbox and into the rotor/propeller without any long shafts involved. There was still a driveshaft along the wings for emergency use to transfer power to the opposite rotor in case of engine failure, but that shaft did not normally carry any power loads, allowing it to be lighter. The tilting engine concept introduced complexities in

1166-457: A military defense force stagnated as they focused on other concerns relevant to setting up the new government. President George Washington went to Congress to remind them of their duty to establish a military twice during this time. Finally, on the last day of the session, September 29, 1789, Congress created the War Department . The War Department handled naval affairs until Congress created

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1272-479: A proposal in 1948 for an aircraft capable of vertical takeoff and landing (VTOL) aboard platforms mounted on the afterdecks of conventional ships. Both Convair and Lockheed competed for the contract but in 1950, the requirement was revised, with a call for a research aircraft capable of eventually evolving into a VTOL ship-based convoy escort fighter. At the end of 1958, the French SNECMA Coléoptère ,

1378-510: A short time later. The Harrier is usually flown in STOVL mode, which enables it to carry a higher fuel or weapon load over a given distance. In V/STOL the VTOL aircraft moves horizontally along the runway before taking off using vertical thrust. This gives aerodynamic lift as well as thrust lift and permits taking off with heavier loads and is more efficient. When landing the aircraft is much lighter due to

1484-543: A successful landing after boosting 11 commercial satellites to low Earth orbit on Falcon 9 Flight 20 . These demonstrations opened the way for substantial reductions in space flight costs. The helicopter's form of VTOL allows it to take off and land vertically, to hover, and to fly forwards, backwards, and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft would usually not be able to take off or land. The capability to efficiently hover for extended periods of time

1590-406: A tailsitter annular wing design, performed its maiden flight. However the sole prototype was destroyed on its ninth flight in 1959, and financing was never sourced for a second prototype. Another more influential early functional contribution to VTOL was Rolls-Royce 's Thrust Measuring Rig ("flying bedstead") of 1953. This led to the first VTOL engines as used in the first British VTOL aircraft,

1696-486: A tilting engines. In the late 1930s British aircraft designer Leslie Everett Baynes was issued a patent for the Baynes Heliplane , another tilt rotor aircraft. In 1941 German designer Heinrich Focke 's began work on the Focke-Achgelis Fa 269 , which had two rotors that tilted downward for vertical takeoff, but wartime bombing halted development. In May 1951, both Lockheed and Convair were awarded contracts in

1802-485: A vertical take-off research aircraft issued in September 1953. The design was accepted by the ministry and a contract was placed for two aircraft (XG900 and XG905) to meet Specification ER.143D dated 15 October 1954. The SC.1 was also equipped with the first "fly-by-wire" control system for a VTOL aircraft. This permitted three modes of control of the aerodynamic surfaces or the nozzle controls. The Republic Aviation AP-100

1908-524: Is an auxiliary jet engine used to provide lift for VTOL operation, but may be shut down for normal wing-borne flight. The Yak-38 is the only production aircraft to employ lift jets. Lift fan is an aircraft configuration in which lifting fans are located in large holes in an otherwise conventional fixed wing or fuselage. It is used for V/STOL operation. The aircraft takes off using the fans to provide lift, then transitions to fixed-wing lift in forward flight. Several experimental craft have been flown, but only

2014-668: Is designed to perform missions like a conventional helicopter with the long-range, high-speed cruise performance of a turboprop aircraft. The FAA classifies the Osprey as a model of powered lift aircraft. Attempts were made in the 1960s to develop a commercial passenger aircraft with VTOL capability. The Hawker Siddeley Inter-City Vertical-Lift proposal had two rows of lifting fans on either side. However, none of these aircraft made it to production after they were dismissed as too heavy and expensive to operate. In 2018 Opener Aero demonstrated an electrically powered fixed-wing VTOL aircraft,

2120-527: Is due to the helicopter's relatively long, and hence efficient rotor blades, and allows a helicopter to accomplish tasks that fixed-wing aircraft and other forms of vertical takeoff and landing aircraft could not perform at least as well until 2011 . On the other hand, the long rotor blades restrict the maximum speed to about 250 miles per hour (400 km/h) of at least conventional helicopters, as retreating blade stall causes lateral instability. Autogyros are also known as gyroplanes or gyrocopters. The rotor

2226-598: Is not military, such as the Department of Homeland Security, counter-terrorism spending by the FBI, and intelligence-gathering spending by the NSA. In the 2010 United States federal budget , the Department of Defense was allocated a base budget of $ 533.7 billion, with a further $ 75.5 billion adjustment in respect of 2009, and $ 130 billion for overseas contingencies. The subsequent 2010 Department of Defense Financial Report shows

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2332-535: Is the secretary and their deputies, including predominantly civilian staff. OSD is the principal staff element of the Secretary of Defense in the exercise of policy development, planning, resource management, fiscal and program evaluation and oversight, and interface and exchange with other U.S. federal government departments and agencies, foreign governments, and international organizations, through formal and informal processes. OSD also performs oversight and management of

2438-421: Is unpowered and rotates freely in the airflow as the craft travels forward, so the craft needs a conventional powerplant to provide thrust. An autogyro is not intrinsically capable of VTOL: for VTO the rotor must be spun up to speed by an auxiliary drive, and vertical landing requires precise control of rotor momentum and pitch. Gyrodynes are also known as compound helicopters or compound gyroplanes. A gyrodyne has

2544-501: The Blackfly , which the manufacturer claims is the world's first ultralight fixed-wing, all-electric, vertical take-off and landing aircraft. In the 21st century, unmanned drones are becoming increasingly commonplace. Many of these have VTOL capability, especially the quadcopter type. In 1947, Ryan X-13 Vertijet , a tailsitter design, was ordered by the US Navy, who then further issued

2650-724: The Central Intelligence Agency , the National Security Council , National Security Resources Board , United States Air Force , and the Joint Chiefs of Staff . The act placed the National Military Establishment under the control of a single secretary of defense . The National Military Establishment formally began operations on September 18, the day after the Senate confirmed James V. Forrestal as

2756-853: The Eisenhower School (ES) and the National War College (NWC). Faced with rising tensions between the Thirteen Colonies and the British government , one of the first actions taken by the First Continental Congress in September 1774 was to recommend that the colonies begin defensive military preparations. In mid-June 1775, after the outbreak of the Revolutionary War , the Second Continental Congress , recognizing

2862-508: The F-35 Lightning II entered into production. Aircraft in which VTOL is achieved by exploiting the Coandă effect are capable of redirecting air much like thrust vectoring , but rather than routing airflow through a duct, the airflow is simply routed along an existing surface, which is usually the body of the craft allowing less material and weight. The Avro Canada VZ-9 Avrocar , or simply

2968-469: The Fairey Gyrodyne , this type of aircraft later evolved into the much larger twin-engined Fairey Rotodyne , that used tipjets to power the rotor on take-off and landing but which then used two Napier Eland turboprops driving conventional propellers mounted on substantial wings to provide propulsion, the wings serving to unload the rotor during horizontal flight. The Rotodyne was developed to combine

3074-624: The Focke-Achgelis Fa 269 of the mid-1940s and the Centro Técnico Aeroespacial "Convertiplano" of the 1950s reached testing or mock-up stages, the Bell-Boeing V-22 Osprey is considered the world's first production tiltrotor aircraft. It has one three-bladed proprotor , turboprop engine, and transmission nacelle mounted on each wingtip. The Osprey is a multi-mission aircraft with both a vertical takeoff and landing (VTOL) and short takeoff and landing capability ( STOL ). It

3180-718: The Hawker P.1127 , which became subsequently the Kestrel and then entered production as the Hawker Siddeley Harrier , though the supersonic Hawker Siddeley P.1154 was canceled in 1965. The French in competition with the P.1154 had developed a version of the Dassault Mirage III capable of attaining Mach 1. The Dassault Mirage IIIV achieved transition from vertical to horizontal flight in March 1966, reaching Mach 1.3 in level flight

3286-511: The Navy Department in 1798. The secretaries of each department reported directly to the president as cabinet-level advisors until 1949, when all military departments became subordinate to the Secretary of Defense. After the end of World War II , President Harry Truman proposed the creation of a unified department of national defense. In a special message to the Congress on December 19, 1945,

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3392-658: The Office of the Director of National Intelligence . They fulfill the requirements of national policymakers and war planners, serve as Combat Support Agencies , and also assist and deploy alongside non-Department of Defense intelligence or law enforcement services such as the Central Intelligence Agency and the Federal Bureau of Investigation . The military services each have their intelligence elements that are distinct from but subject to coordination by national intelligence agencies under

3498-455: The Short SC.1 (1957), Short Brothers and Harland, Belfast which used four vertical lift engines with a horizontal one for forward thrust. The Short SC.1 was the first British fixed-wing VTOL aircraft. The SC.1 was designed to study the problems with VTOL flight and the transition to and from forward flight. The SC.1 was designed to meet a Ministry of Supply (MoS) request for tender (ER.143T) for

3604-688: The deputy secretary of defense . Secretaries of military departments, in turn, normally exercise authority over their forces by delegation through their respective service chiefs (i.e., Chief of Staff of the Army , Commandant of the Marine Corps , Chief of Naval Operations , Chief of Staff of the Air Force , and Chief of Space Operations ) over forces not assigned to a Combatant Command . Secretaries of Military Departments and service chiefs do not possess operational command authority over U.S. troops (this power

3710-511: The fiscal year 2024 (FY2024) presidential budget request was $ 842   billion. In January 2023 Treasury Secretary Janet Yellen announced the US government would hit its $ 31.4   trillion debt ceiling on 19 January 2023; the date on which the US government would no longer be able to use extraordinary measures such as issuance of Treasury securities is estimated to be in June 2023. On 3 June 2023,

3816-515: The lunar module (LEM), which had to rely on a reaction engine to land on the Moon. The idea of using the same engine for vertical and horizontal flight by altering the path of the thrust was conceived by Michel Wibault . It led to the Bristol Siddeley Pegasus engine which used four rotating nozzles to direct thrust over a range of angles. This was developed side by side with an airframe,

3922-566: The 1960s and early 1970s, Germany planned three different VTOL aircraft. One used the Lockheed F-104 Starfighter as a basis for research for a V/STOL aircraft. Although two models (X1 and X2) were built, the project was canceled due to high costs and political problems as well as changed needs in the German Air Force and NATO. The EWR VJ 101 C did perform free VTOL take-offs and landings, as well as test flights beyond mach 1 in

4028-492: The 3 km and 6 km time-to-climb. The first XV-15 prototype aircraft, N702NA, was transferred back to Bell for company development and demonstration use. On 20 August 1992, the aircraft crashed while being flown by a guest test pilot. He was lifting off for a final hover when a bolt slipped out of the collective control system on one pylon, causing that rotor to go to full pitch. The aircraft rolled upside down out of control and crashed inverted. While significantly damaged,

4134-625: The Army , Secretary of the Navy and Secretary of the Air Force ), appointed by the president, with the advice and consent of the Senate . They have the legal authority under Title 10 of the United States Code to conduct all the affairs of their respective departments within which the military services are organized. The secretaries of the Military Departments are (by law) subordinate to the secretary of defense and (by SecDef delegation) to

4240-1162: The British Royal Air Force and Royal Navy. The United States Marine Corps and the Italian and Spanish navies all continue to use the AV-8B Harrier II , an American-British variant. Replacing the Harrier II/AV-8B in the air arms of the US and UK is the STOVL variant of the Lockheed Martin F-35 Lightning II , the F-35B. SpaceX developed several prototypes of Falcon 9 to validate various low-altitude, low-velocity engineering aspects of its reusable launch system development program . The first prototype, Grasshopper, made eight successful test flights in 2012–2013. It made its eighth, and final, test flight on October 7, 2013, flying to an altitude of 744 metres (2,441 ft) before making its eighth successful VTVL landing. This

4346-582: The CIA's human intelligence efforts while also focusing on military human intelligence priorities. These agencies are directly overseen by the Under Secretary of Defense for Intelligence and Security . The Joint Chiefs of Staff (JCS) is a body of senior uniformed leaders in the Department of Defense who advise the secretary of defense, the Homeland Security Council , the National Security Council and

Bell XV-15 - Misplaced Pages Continue

4452-754: The Chairman of the Joint Chiefs of Staff (CJCS) as the "principal military adviser to the President, the National Security Council, the Homeland Security Council, and the Secretary of Defense". The remaining Joint Chiefs of Staff may only have their advice relayed to the President, National Security Council, the Homeland Security Council , or the Secretary of Defense after submitting it to the CJCS. By law,

4558-540: The Defense Agencies, Department of Defense Field Activities, and specialized Cross Functional Teams . OSD is a parent agency of the following defense agencies: Several defense agencies are members of the United States Intelligence Community . These are national-level intelligence services that operate under the Department of Defense jurisdiction but simultaneously fall under the authorities of

4664-514: The Department of Defense budget, such as nuclear weapons research, maintenance, cleanup, and production, which is in the Department of Energy budget, Veterans Affairs, the Treasury Department's payments in pensions to military retirees and widows and their families, interest on debt incurred in past wars, or State Department financing of foreign arms sales and militarily-related development assistance. Neither does it include defense spending that

4770-464: The Department of Defense. Department of Defense manages the nation's coordinating authorities and assets in disciplines of signals intelligence , geospatial intelligence , and measurement and signature intelligence , and also builds, launches, and operates the Intelligence Community's satellite assets. Department of Defense also has its own human intelligence service , which contributes to

4876-597: The FY 2019 budget: "The overall number you often hear is $ 716 billion. That is the amount of funding for national defense, the accounting code is 050 and includes more than simply the Department of Defense. It includes, for example, the Department of Energy and others. That large a number, if you back out the $ 30 billion for non-defense agencies, you get to $ 686 billion. That is the funding for the Department of Defense, split between $ 617 billion in base and $ 69 billion in overseas contingency ". The Department of Defense budget encompasses

4982-509: The FY2018 Budget expired and the FY2019 budget came into effect. The FY2019 Budget for the Department of Defense is approximately $ 686,074,048,000 (Including Base + Overseas Contingency Operations + Emergency Funds) in discretionary spending and $ 8,992,000,000 in mandatory spending totaling $ 695,066,000,000 Undersecretary of Defense (Comptroller) David L. Norquist said in a hearing regarding

5088-773: The Joint Chiefs of Staff ( JCS ) and the Joint Staff ( JS ), Office of the Inspector General ( DODIG ), the Combatant Commands , the Military Departments ( Department of the Army (DA), Department of the Navy (DON) & Department of the Air Force (DAF)), the Defense Agencies and Department of Defense Field Activities , the National Guard Bureau (NGB), and such other offices, agencies, activities, organizations, and commands established or designated by law, or by

5194-584: The NDAA on 14 December 2023. The Senate will next undertake negotiations on supplemental spending for 2024. A government shutdown was averted on 23 March 2024 with the signing of a $ 1.2 trillion bill to cover FY2024. A 2013 Reuters investigation concluded that Defense Finance & Accounting Service , the Department of Defense's primary financial management arm, implements monthly "unsubstantiated change actions"—illegal, inaccurate "plugs"—that forcibly make DoD's books match Treasury's books. Reuters reported that

5300-1013: The National Security Agency ( NSA ), the National Geospatial-Intelligence Agency ( NGA ), and the National Reconnaissance Office ( NRO ). Other Defense agencies include the Defense Advanced Research Projects Agency ( DARPA ), the Defense Logistics Agency ( DLA ), the Missile Defense Agency ( MDA ), the Defense Health Agency ( DHA ), Defense Threat Reduction Agency ( DTRA ), the Defense Counterintelligence and Security Agency ( DCSA ),

5406-416: The Pentagon was the only federal agency that had not released annual audits as required by a 1992 law. According to Reuters, the Pentagon "annually reports to Congress that its books are in such disarray that an audit is impossible". In 2015, a Pentagon consulting firm performed an audit on the Department of Defense's budget. It found that there was $ 125 billion in wasteful spending that could be saved over

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5512-442: The President to the Secretary of Defense, the service chief of the Unified Combatant Commander(s), and then to the unified combatant commander(s). Also provided in this legislation was a centralized research authority, the Advanced Research Projects Agency , eventually known as DARPA . The act was written and promoted by the Eisenhower administration and was signed into law on August 6, 1958. The Secretary of Defense , appointed by

5618-458: The Space Development Agency ( SDA ) and the Pentagon Force Protection Agency ( PFPA ), all of which are subordinate to the secretary of defense. Additionally, the Defense Contract Management Agency ( DCMA ) is responsible for administering contracts for the Department of Defense. Military operations are managed by eleven regional or functional unified combatant commands . The Department of Defense also operates several joint services schools, including

5724-521: The U.S. government directly related to national security and the United States Armed Forces . As of November 2022, the U.S. Department of Defense is the second largest employer in the world after India (and potentially China, if including the Central Military Commission), with over 1.4  million active-duty service personnel, including soldiers, marines, sailors, airmen, and guardians. The Department of Defense also maintains over 778,000 National Guard and reservists, and over 747,000 civilians, bringing

5830-425: The Unified Combatant Commands are responsible for military forces' actual operational command. Almost all operational U.S. forces are under the authority of a Unified Command. The Unified Commands are governed by a Unified Command Plan —a frequently updated document (produced by the DoD), which lays out the Command's mission, geographical/functional responsibilities, and force structure. During military operations,

5936-422: The United States , the latter of which is also the commander-in-chief of the United States Armed Forces . Beneath the Department of Defense are three subordinate military departments: the Department of the Army , the Department of the Navy , and the Department of the Air Force . In addition, four national intelligence services are subordinate to the Department of Defense: the Defense Intelligence Agency ( DIA ),

6042-417: The VZ-9, was a Canadian VTOL aircraft developed by Avro Aircraft Ltd. which utilizes this phenomenon by blowing air into a central area, then it is directed down over the top surface, which is parabolic and resembles a bowed flying saucer . Due to the Coandă effect, the airflow is attracted to the nearest surface and continues to move along that surface despite the change in the surface's direction away from

6148-834: The World's Aircraft 1988-89 General characteristics Performance Related development Aircraft of comparable role, configuration, and era Related lists VTOL A vertical take-off and landing ( VTOL ) aircraft is one that can take off and land vertically without relying on a runway . This classification can include a variety of types of aircraft including helicopters as well as thrust-vectoring fixed-wing aircraft and other hybrid aircraft with powered rotors such as cyclogyros/cyclocopters and gyrodynes . Some VTOL aircraft can operate in other modes as well, such as CTOL (conventional take-off & landing), STOL (short take-off & landing), or STOVL (short take-off & vertical landing). Others, such as some helicopters, can only operate as VTOL, due to

6254-452: The XV-3 project. One of the major problems with the early tiltrotor aircraft designs was that the driveshafts carrying power from the fuselage out to the wingtip rotors, along with the gearbox and tilting mechanisms at the wingtips, had substantial loads placed upon them and were heavy. They were transferring large amounts of power and torque long distances for an aircraft power transmission system. The XV-15 experimental aircraft introduced

6360-627: The aircraft lacking landing gear that can handle taxiing . VTOL is a subset of V/STOL (vertical or short take-off & landing). Some lighter-than-air aircraft also qualify as VTOL aircraft, as they can hover, takeoff and land with vertical approach/departure profiles. Electric vertical takeoff and landing aircraft, or eVTOLs , are being developed along with more autonomous flight control technologies and mobility-as-a-service (MaaS) to enable advanced air mobility (AAM), that could include on-demand air taxi services, regional air mobility, freight delivery, and personal air vehicles (PAVs). Besides

6466-518: The aircraft was largely structurally intact and both the pilot and copilot escaped with only minor injuries from the crash. The cockpit of the aircraft was salvaged and converted for use as a flight simulator . The second XV-15 prototype, N703NA, was used for tests supporting the military V-22 Osprey program and Bell/Agusta BA609 civilian transport (still under development in 2023 as the AgustaWestland AW609). It continued in primarily NASA test operations until September 2003. The shortest takeoff distance

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6572-563: The airflow. The craft is designed to direct the airflow downward to provide lift. Jetoptera announced a proposed line of aircraft based on what it called fluidic propulsion that employs the Coandă effect. The company claims an Oswald efficiency number of 1.45 for its boxwing design. Other claims include increased efficiency, 30% lower weight, reduced complexity, as much as 25 dBA lower (and atonal) noise, shorter wings, and scalability. Jetoptera says its approach yields thrust augmentation ratios exceeding 2.0 and 50% fuel savings when compared to

6678-521: The allocation for the Department of Defense was $ 585  billion, the highest level of budgetary resources among all federal agencies, and this amounts to more than one-half of the annual federal expenditures in the United States federal budget discretionary budget . On September 28, 2018, President Donald Trump signed the Department of Defense and Labor, Health and Human Services, and Education Appropriations Act, 2019, and Continuing Appropriations Act, 2019 (H.R.6157) into law. On September 30, 2018,

6784-445: The attempt to design, construct, and test two experimental VTOL fighters. Lockheed produced the XFV , and Convair producing the Convair XFY Pogo . Both experimental programs proceeded to flight status and completed test flights 1954–1955, when the contracts were cancelled. Similarly, the Ryan X-13 Vertijet flew a series of test flights between 1955 and 1957, but also suffered the same fate. The use of vertical fans driven by engines

6890-438: The budgeted global military spending – more than the next 7 largest militaries combined. By 2019, the 27th secretary of defense had begun a line-by-line review of the defense budget; in 2020 the secretary identified items amounting to $ 5.7 billion, out of a $ 106 billion subtotal (the so-called "fourth estate" agencies such as missile defense, and defense intelligence, amounting to 16% of the defense budget), He will re-deploy to

6996-404: The chain of command runs from the president to the secretary of defense to the combatant commanders of the Combatant Commands. As of 2019 , the United States has eleven Combatant Commands, organized either on a geographical basis (known as " area of responsibility ", AOR) or on a global, functional basis: Department of Defense spending in 2017 was 3.15% of GDP and accounted for about 38% of

7102-430: The chairman has to present that advice whenever he is presenting his own. The chain of command goes from the president to the secretary of defense to the commanders of the Combatant Commands . Goldwater–Nichols also created the office of vice-chairman, and the chairman is now designated as the principal military adviser to the secretary of defense, the Homeland Security Council, the National Security Council and to

7208-413: The co-located Moffett Field Naval Air Station for several years during the 1980s. Both XV-15s were flown actively throughout the 1980s testing aerodynamics and tiltrotor applications for civilian and military aircraft types that might follow. The Fédération Aéronautique Internationale classifies the XV-15 as a Rotodyne, and as such it holds the speed record of 456 kilometres per hour (283 mph), and

7314-440: The debt ceiling was suspended until 2025. The $ 886   billion National Defense Authorization Act is facing reconciliation of the House and Senate bills after passing both houses 27 July 2023; the conferees have to be chosen, next. As of September 2023, a Continuing resolution is needed to prevent a Government shutdown . A shutdown was avoided on 30 September for 45 days (until 17 November 2023), with passage of

7420-438: The department were streamlined while still maintaining the ordinary jurisdiction of the Military Departments to organize, train, and equip their associated forces. The Act clarified the overall decision-making authority of the secretary of defense concerning these subordinate Military Departments. It more clearly defined the operational chain of command over U.S. military forces (created by the military departments) as running from

7526-438: The design of the engines and engine pods to be able to shift from operating horizontally to operating vertically. Those problems were addressed fairly early in the XV-15 program. In the late 1960s and early 1970s, NASA and other researchers worked extensively on theoretical and wind tunnel tests of various rotor pods. Two companies were involved in the research and proposing designs: Bell Helicopter and Boeing Vertol . The focus

7632-680: The development of the Panavia Tornado . The Yakovlev Yak-38 was a Soviet Navy VTOL aircraft intended for use aboard their light carriers, cargoships, and capital ships. It was developed from the Yakovlev Yak-36 experimental aircraft in the 1970s. Before the Soviet Union broke up, a supersonic VTOL aircraft was developed as the Yak-38's successor, the Yak-141 , which never went into production. In

7738-490: The efficiency of a fixed-wing aircraft at cruise with the VTOL capability of a helicopter to provide short haul airliner service from city centres to airports. The CL-84 Dynavert was a Canadian V/STOL turbine tilt-wing monoplane designed and manufactured by Canadair between 1964 and 1972. The Canadian government ordered three updated CL-84s for military evaluation in 1968, designated the CL-84-1. From 1972 to 1974, this version

7844-509: The engine and rotor assembly fixed together within the pod. This simplified the power transmission, but it had more complicated requirements for the engine design and was probably slightly heavier than the Boeing proposal. After a review of both proposals, NASA selected the Bell 301 for further development, and a contract for further R&D was issued on 31 July 1973. Extensive engineering and testing took

7950-564: The first secretary of defense. The National Military Establishment was renamed the "Department of Defense" on August 10, 1949, and absorbed the three cabinet-level military departments, in an amendment to the original 1947 law. The renaming is alleged to be due to the Establishment's abbreviation, NME, being pronounced "enemy". Under the Department of Defense Reorganization Act of 1958 ( Pub. L.   85–599 ), channels of authority within

8056-404: The jurisdiction of other congressional committees. The Department of Defense is unique because it is one of the few federal entities where the majority of its funding falls into the discretionary category. The majority of the entire federal budget is mandatory, and much of the discretionary funding in the budget consists of DoD dollars. * Numbers may not add due to rounding As of 10 March 2023

8162-446: The later Bell 222 conventional helicopter), in which the engines were in fixed pods at the end of each wing, and a small, rotating pod with the rotor was slightly closer to the fuselage on the wing. This design simplified the engine design by keeping it horizontal at all times without having very long driveshafts to the tilting rotors. In the Bell design, Bell Model 301, the whole wingtip pod rotated between horizontal and vertical, with

8268-493: The latest Center for Effective Government analysis of 15 federal agencies which receive the most Freedom of Information Act requests, published in 2015 (using 2012 and 2013 data, the most recent years available), the DoD earned 61 out of a possible 100 points, a D− grade. While it had improved from a failing grade in 2013, it still had low scores in processing requests (55%) and disclosure rules (42%). The organization and functions of

8374-418: The loss of propellant weight and a controlled vertical landing is possible. An important aspect of Harrier STOL operations aboard naval carriers is the "ski jump" raised forward deck, which gives the craft additional vertical momentum at takeoff. The March 1981 cover of Popular Science showed three illustrations for its "Tilt-engine V/STOL - speeds like a plane, lands like a copter" front-page feature story.;

8480-561: The majority of the National Defense Budget of approximately $ 716.0 billion in discretionary spending and $ 10.8 billion in mandatory spending for a $ 726.8 billion total. Of the total, $ 708.1 billion falls under the jurisdiction of the House Committee on Armed Services and Senate Armed Services Committee and is subject to authorization by the annual National Defense Authorization Act (NDAA). The remaining $ 7.9 billion falls under

8586-671: The mid- and late 60s. One of the test-aircraft is preserved in the Deutsches Museum in Munich, Germany, another outside Friedrichshafen Airport. The others were the VFW-Fokker VAK 191B light fighter and reconnaissance aircraft, and the Dornier Do 31 E-3 (troop) transport. The LLRV was a spacecraft simulator for the Apollo lunar lander. It was designed to mimic the flight characteristics of

8692-589: The modernization of hypersonics, artificial intelligence, and missile defense. Beyond 2021 the 27th secretary of defense is projecting the need for yearly budget increases of 3 to 5 percent to modernize. The Department of Defense accounts for the majority of federal discretionary spending. In FY 2017, the Department of Defense budgeted spending accounted for 15% of the U.S. federal budget, and 49% of federal discretionary spending , which represents funds not accounted for by pre-existing obligations. However, this does not include many military-related items that are outside

8798-633: The necessity of having a national army that could move about and fight beyond the boundaries of any particular colony, organized the Continental Army on June 14, 1775. This momentous event is commemorated in the U.S. annually as Flag Day . Later that year, Congress would charter the Continental Navy on October 13, and the Continental Marines on November 10. Upon the seating of the 1st U.S. Congress on March 4, 1789, legislation to create

8904-579: The next five years without layoffs or reduction in military personnel. In 2016, The Washington Post uncovered that rather than taking the advice of the auditing firm, senior defense officials suppressed and hid the report from the public to avoid political scrutiny. In June 2016, the Office of the Inspector General released a report stating that the Army made $ 6.5 trillion in wrongful adjustments to its accounting entries in 2015. The Department of Defense failed its fifth audit in 2022, and could not account for more than 60% of its $ 3.5 trillion in assets. In

9010-609: The next four years to complete the development of the aircraft. The first of two Bell XV-15s, tail number N702NA , first flew on 3 May 1977. After minimal flight tests at the Bell test facility, the aircraft was moved to Ames Research Center in Sunnyvale, California, where it was then mounted in the large Ames wind tunnel and tested extensively in various simulated flight environments. For the U.S. Department of Defense Joint-service Vertical take-off/landing Experimental (JVX) aircraft program, Bell Helicopter and Boeing Vertol teamed to submit

9116-534: The one-seat Transcendental Model 1-G and two-seat Transcendental Model 2, both powered by single reciprocating engines. Development started on the Model 1-G in 1947, and it flew in 1954. The Model 1-G flew until a crash in Chesapeake Bay on 20 July 1955, destroying the prototype aircraft but not seriously injuring the pilot. The Transcendental 1-G was the first tiltrotor aircraft to have flown, and it accomplished most of

9222-590: The powered rotor of a helicopter with a separate forward thrust system of an autogyro. Apart from take-off and landing the rotor may be unpowered and autorotate. Designs may also include stub wings for added lift. A cyclogyro or cyclocopter has a rotary wing whose axis and surfaces remain sideways across the airflow, as with a conventional wing. There are number of designs for achieving power lift, and some designs may use more than one. There are many experimental designs that have unique design features to achieve powered lift. A convertiplane takes off under rotor lift like

9328-530: The president cited wasteful military spending and interdepartmental conflicts. Deliberations in Congress went on for months focusing heavily on the role of the military in society and the threat of granting too much military power to the executive. On July 26, 1947, Truman signed the National Security Act of 1947 , which set up a unified military command known as the National Military Establishment and created

9434-603: The president following U.S. Senate confirmation. Each of the individual Military Service Chiefs, outside their Joint Chiefs of Staff obligations, works directly for the secretary of the military department concerned: the Secretary of the Army , Secretary of the Navy , and Secretary of the Air Force . Following the Goldwater–Nichols Act in 1986, the Joint Chiefs of Staff no longer maintained operational command authority individually or collectively. The act designated

9540-547: The president on military matters. The composition of the Joint Chiefs of Staff is defined by statute and consists of the chairman of the Joint Chiefs of Staff (CJCS), vice chairman of the Joint Chiefs of Staff (VCJCS), senior enlisted advisor to the chairman (SEAC), the Military Service chiefs from the Army , Marine Corps , Navy , Air Force , and Space Force , in addition to the chief of National Guard Bureau , all appointed by

9646-422: The president or by the secretary of defense. Department of Defense Directive 5100.01 describes the organizational relationships within the department and is the foundational issuance for delineating the major functions of the department. The latest version, signed by former Secretary of Defense Robert Gates in December 2010, is the first major re-write since 1987. The Office of the Secretary of Defense ( OSD )

9752-464: The president with the advice and consent of the Senate , is by federal law ( 10 U.S.C.   § 113 ) the head of the Department of Defense, "the principal assistant to the President in all matters relating to Department of Defense", and has "authority, direction, and control over the Department of Defense". Because the Constitution vests all military authority in Congress and the president,

9858-560: The president. The Joint Staff (JS) is a headquarters staff at the Pentagon made up of personnel from all five services that assist the chairman and vice chairman in discharging their duties. It is managed by the Director of the Joint Staff (DJS) who is a lieutenant general or vice admiral . There are three military departments within the Department of Defense: The Military Departments are each headed by their secretary (i.e., Secretary of

9964-470: The statutory authority of the secretary of defense is derived from their constitutional authority. Since it is impractical for either Congress or the president to participate in every piece of Department of Defense affairs, the secretary of defense and the secretary's subordinate officials generally exercise military authority. The Department of Defense is composed of the Office of the Secretary of Defense ( OSD ),

10070-456: The total budgetary resources for fiscal year 2010 were $ 1.2 trillion. Of these resources, $ 1.1 trillion were obligated and $ 994 billion were disbursed, with the remaining resources relating to multi-year modernization projects requiring additional time to procure. After over a decade of non-compliance , Congress has established a deadline of Fiscal year 2017 for the Department of Defense to achieve audit readiness . In 2015

10176-522: The total to over 2.91  million employees. Headquartered at the Pentagon in Arlington County, Virginia , just outside Washington, D.C. , the Department of Defense's stated mission is "to provide the military forces needed to deter war and ensure our nation's security". The Department of Defense is headed by the secretary of defense , a cabinet-level head who reports directly to the president of

10282-763: The ubiquitous helicopters, there are currently two types of VTOL aircraft in military service: tiltrotor aircraft, such as the Bell Boeing V-22 Osprey , and thrust-vectoring airplanes, such as the Harrier family and new F-35B Lightning II Joint Strike Fighter (JSF). In the civilian sector currently only helicopters are in general use (some other types of commercial VTOL aircraft have been proposed and are under development as of 2017 ). Generally speaking, VTOL aircraft capable of STOVL use it wherever possible, since it typically significantly increases takeoff weight, range or payload compared to pure VTOL. The idea of vertical flight has been around for thousands of years, and sketches for

10388-460: Was a lovable plane, it is the Bell XV-15... The machine, the hit of the show, performed a series of maneuvers including bowing to the crowd." Over the next year, Senator Barry Goldwater, Navy Secretary John Lehman, and other officials were offered guest co-piloting flights to promote tiltrotor technology for military development. The XV-15s were a standard demonstration in the annual summer airshow at

10494-564: Was a prototype VTOL 6x General Electric J85 Turbojet engined nuclear capable strike fighter concept designed by Alexander Kartveli that had 3x ducted fans in the centre of its fuselage and tail as a possible contender for the TFX Program . Another design was the A400 AVS that used variable geometry wings but was found too complicated, however it led to the development of the AFVG which in turn helped

10600-436: Was able to successfully operate in both helicopter and normal aircraft flight modes and smoothly transition between the two. Once the aircraft was considered sufficiently tested, it was returned to Ames Research Center for further testing. The XV-15s were deemed sufficiently tested, and one aircraft was taken to the 1981 Paris Air Show for demonstration flights. The New York Times praised its performance. "And if ever there

10706-597: Was achieved with the nacelles at 75 degrees angle. After N703NA was retired from test operations, it was donated to the Smithsonian National Air and Space Museum in Washington, D.C. The XV-15 was flown cross-country from Fort Worth, Texas to the museum before being decommissioned for display. It is now on display at the Steven F. Udvar-Hazy Center at Washington Dulles International Airport . Data from Jane's All

10812-540: Was demonstrated and evaluated in the United States aboard the aircraft carriers USS Guam and USS Guadalcanal , and at various other centres. These trials involved military pilots from the United States, the United Kingdom and Canada. During testing, two of the CL-84s crashed due to mechanical failures, but no loss of life occurred as a result of these accidents. No production contracts resulted. Although tiltrotors such as

10918-558: Was investigated in the 1950s. The US built an aircraft where the jet exhaust drove the fans , while British projects not built included fans driven by mechanical drives from the jet engines. NASA has flown other VTOL craft such as the Bell XV-15 research craft (1977), as have the Soviet Navy and Luftwaffe . Sikorsky tested an aircraft dubbed the X-Wing , which took off in the manner of

11024-780: Was on tilt-rotor pods, integration of the tilting rotors with the wings and fuselage of the aircraft, and studying the airflow as the rotors tilted. Tilt rotors with fixed rotors and with folding rotors were investigated. What was to become the XV-15 program was launched in 1971 at NASA Ames Research Center . After preliminary work, a competition was held to award two $ 0.5 million research and development contracts for prototype designs. Companies that responded included Sikorsky Aircraft , Grumman Aircraft , Boeing Vertol, and Bell Helicopter. R&D contracts were issued to Bell Helicopter and Boeing Vertol on 20 October 1972. The two companies' design proposals were delivered on 22 January 1973. Boeing Vertol proposed its Model 222 (not to be confused with

11130-525: Was stripped from them in the Defense Reorganization Act of 1958 ), and instead, Military Departments are tasked solely with "the training, provision of equipment, and administration of troops." A unified combatant command is a military command composed of personnel/equipment from at least two Military Departments, which has a broad/continuing mission. These military departments are responsible for equipping and training troops to fight, while

11236-635: Was the last scheduled test for the Grasshopper rig; next up will be low altitude tests of the Falcon 9 Reusable (F9R) development vehicle in Texas followed by high altitude testing in New Mexico. On November 23, 2015, Blue Origin 's New Shepard booster rocket made the first successful vertical landing following an uncrewed suborbital test flight that reached space. On December 21, 2015, SpaceX Falcon 9 first stage made

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