Misplaced Pages

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96-504: The XV-3 was first flown on 11 August 1955. The first prototype use three blade rotors, and had issue with flutter crashing two months after its first flight. Tests were conducted on the second prototype with 2-blade rotors and flew successfully. Although it was limited in performance compared to later types, the aircraft successfully demonstrated the tiltrotor concept, accomplishing 110 transitions from helicopter to airplane mode between December 1958 and July 1962. The XV-3 program ended when

192-499: A GSU under AFRC's 920th Rescue Wing at Patrick Space Force Base is equipped with HH-60G Pave Hawk helicopters and Guardian Angel personnel. The 943 RQG is tasked to provide combat search and rescue (CSAR) and personnel recovery (PR) support worldwide. The 924th Fighter Group , originally a classic associate unt to the 355 FW, now 355 WG, flies the A-10 Thunderbolt II and is now equipped with its own aircraft. Perhaps

288-451: A clamped-free beam (i.e., a cantilever wing) are which yields the solution As can be seen, for λL = π /2 + nπ , with arbitrary integer number n , tan( λL ) is infinite. n = 0 corresponds to the point of torsional divergence. For given structural parameters, this will correspond to a single value of free-stream velocity U . This is the torsional divergence speed. Note that for some special boundary conditions that may be implemented in

384-433: A continuous stream of vortices known as a Kármán vortex street , which can induce structural oscillations. Strakes are typically wrapped around chimneys to stop the formation of these vortices. In complex structures where both the aerodynamics and the mechanical properties of the structure are not fully understood, flutter can be discounted only through detailed testing. Even changing the mass distribution of an aircraft or

480-554: A halt on 14 August 1945, when the Japanese surrendered. Davis–Monthan played a post-war role by housing German POWs from June 1945 to March 1946. It also served as a separation center, which brought the base populace to a high of 11,614 in September 1945. With the end of the war, operations at the base came to a virtual standstill. It was then that the base was selected as a storage site for hundreds of decommissioned aircraft, with

576-463: A military aircraft accident completing a training mission on December 28, 1921, while a passenger in a Curtiss JN-6HG at Carlstrom Field , near Arcadia, Florida . One other person, William C. Sinclair, was also killed. They were hunting ducks at the time; Sinclair was piloting and Davis was shooting. After a funeral at the home of his parents, Davis was buried at Evergreen Cemetery in Tucson. He

672-552: A move in 1927 to the site which is now Davis–Monthan Air Force Base. The City of Tucson acquired land southeast of town for a runway and dedicated the field in 1925. Charles Lindbergh , fresh from his nonstop crossing of the Atlantic Ocean, flew his Spirit of St. Louis to Tucson in 1927 to dedicate the airport at Davis–Monthan Field, then the largest municipal airport in the United States. Military presence at

768-529: A sudden impulse of load increasing. It is a random forced vibration. Generally it affects the tail unit of the aircraft structure due to air flow downstream of the wing. The methods for buffet detection are: In the period 1950–1970, AGARD developed the Manual on Aeroelasticity which details the processes used in solving and verifying aeroelastic problems along with standard examples that can be used to test numerical solutions. Aeroelasticity involves not just

864-497: A theory of wing divergence, leading to much further theoretical research on the subject. The term aeroelasticity itself was coined by Harold Roxbee Cox and Alfred Pugsley at the Royal Aircraft Establishment (RAE), Farnborough in the early 1930s. In the development of aeronautical engineering at Caltech , Theodore von Kármán started a course "Elasticity applied to Aeronautics". After teaching

960-547: A wind tunnel test of an airfoil (e.g., a torsional restraint positioned forward of the aerodynamic center) it is possible to eliminate the phenomenon of divergence altogether. Control surface reversal is the loss (or reversal) of the expected response of a control surface, due to deformation of the main lifting surface. For simple models (e.g. single aileron on an Euler-Bernoulli beam), control reversal speeds can be derived analytically as for torsional divergence. Control reversal can be used to aerodynamic advantage, and forms part of

1056-519: Is best known as the location of the Air Force Materiel Command 's 309th Aerospace Maintenance and Regeneration Group (309 AMARG), the aircraft boneyard for all excess military and U.S. government aircraft and aerospace vehicles. Davis–Monthan Air Force Base is a key ACC installation. The 355th Wing (355 WG) provides A-10 Thunderbolt II close air support and OA-10 forward air controllers to ground forces worldwide. The 355 WG

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1152-558: Is known as aerothermoelasticity , and its synthesis with control theory is known as aeroservoelasticity . The second failure of Samuel Langley 's prototype plane on the Potomac was attributed to aeroelastic effects (specifically, torsional divergence). An early scientific work on the subject was George Bryan 's Theory of the Stability of a Rigid Aeroplane published in 1906. Problems with torsional divergence plagued aircraft in

1248-692: Is now part of the Total Force Enterprise, and is the only unit-equipped both active and classic associate fighter group in Air Force Reserve Command's inventory. With oversight of the 47th Fighter Squadron, 924th MS, and 924th OSF, the group is charged with working with the Regular Air Force's 355th Fighter Wing to functionally integrate with the 355th Operations Group and 355th Maintenance Group to conduct A-10 pilot training at Davis–Monthan AFB. Davis–Monthan

1344-437: Is the elastic twist of the beam, GJ is the torsional stiffness of the beam, L is the beam length, and M ’ is the aerodynamic moment per unit length. Under a simple lift forcing theory the aerodynamic moment is of the form where C is a coefficient, U is the free-stream fluid velocity, and α 0 is the initial angle of attack. This yields an ordinary differential equation of the form where The boundary conditions for

1440-639: Is the host unit, providing medical, logistical, mission and operational support to assigned units. The 355 WG is the sole formal training unit for the A-10 aircraft, providing initial and recurrent training to all U.S. Air Force A-10 and OA-10 pilots, to include those in the Air Force Reserve Command (AFRC) and the Air National Guard (ANG). The 355th is ACC's executive agent for INF and START treaty compliance. In October 2018,

1536-399: Is the point at which the structure is undergoing simple harmonic motion —zero net damping —and so any further decrease in net damping will result in a self-oscillation and eventual failure. "Net damping" can be understood as the sum of the structure's natural positive damping and the negative damping of the aerodynamic force. Flutter can be classified into two types: hard flutter , in which

1632-549: The 390th Strategic Missile Wing on 30 June 1984. One site under the 390 SMW, known both as Titan II Site 571-7 and as Air Force Facility Missile Site 8, was initially decommissioned in 1982. Located approximately 12 miles (19 km) south of Tucson in Sahuarita, Arizona , it was saved from demolition and turned over to the Arizona Aerospace Foundation, a nonprofit organization which also administers

1728-564: The 563rd Rescue Group , previously a geographically separated unit of the 23rd Wing at Moody AFB , Georgia, was transferred to the 355th Wing, along with its HC-130J COMBAT KING II and HH-60G Pave Hawk aircraft. One of the wing's tenant units, the 55th Electronic Combat Group (55 ECG), is a geographically separated unit (GSU) of the 55th Wing (55 WG) at Offutt AFB , Nebraska. Tasked to provide offensive counter-information and electronic attack capabilities in support of U.S. and Coalition tactical air, surface, and special operations forces,

1824-451: The 868th Tactical Missile Training Group (866 TMTG). The 868th was the only U.S.-based Ground Launched Cruise Missile (GLCM) unit and the source of the crews that staffed the forward deployed GLCM wings in NATO in 1982. On 1 September 1982, the headquarters of the 602d Tactical Air Control Wing (TAIRCW) and its subordinate 23rd Tactical Air Support Squadron (TASS), a unit responsible for

1920-509: The A-7 Corsair II aircraft, was activated at the base and the previously assigned F-4s were moved to Luke AFB , near Phoenix, Arizona . On 1 October 1976, the base was transferred to Tactical Air Command (TAC) after 30 years under SAC, with SAC's 390th Strategic Missile Wing becoming a tenant command of the base. It was also that year the 355th Tactical Fighter Wing accepted the first A-10 Thunderbolt II . Since 1979, D–M has been

2016-490: The First World War and were solved largely by trial-and-error and ad hoc stiffening of the wing. The first recorded and documented case of flutter in an aircraft was that which occurred to a Handley Page O/400 bomber during a flight in 1916, when it suffered a violent tail oscillation, which caused extreme distortion of the rear fuselage and the elevators to move asymmetrically. Although the aircraft landed safely, in

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2112-451: The Kaman servo-flap rotor design. Dynamic aeroelasticity studies the interactions among aerodynamic, elastic, and inertial forces. Examples of dynamic aeroelastic phenomena are: Flutter is a dynamic instability of an elastic structure in a fluid flow, caused by positive feedback between the body's deflection and the force exerted by the fluid flow. In a linear system , "flutter point"

2208-679: The Lucky Lady II ' s crew received the Mackay Trophy , given annually by the National Aeronautic Association for the outstanding flight of the year, and the Air Age Trophy, an Air Force Association award, given each year in recognition of significant contributions to the public understanding of the air age. In 1953, the jet age came to Davis–Monthan when SAC units on the base converted to

2304-412: The Lucky Lady II , a B-50A of the 43d Bombardment Wing, completed the first nonstop round-the-world flight, having covered 23,452 miles (37,742 km) in 94 hours and 1 minute (249.45 mph). Lucky Lady II was refueled four times in the air by KB-29 tankers of the 43d Air Refueling Squadron, which had made only one operational air refueling contact before the mission. For this outstanding flight,

2400-691: The Pima Air and Space Museum immediately south of Davis–Monthan AFB. With a variety of items on loan from the National Museum of the United States Air Force , including an inert Titan II missile, Site 571-7 is now known as the Titan Missile Museum and is one of two remaining examples of a Titan II missile site in existence (the other being located at Vandenberg Space Force Base , California; site 395-C). In 1994,

2496-640: The United States Air Force as independent service four months earlier, the facility was renamed Davis–Monthan Air Force Base . On 30 June 1948, the Air Force activated the 43rd Air Refueling Squadron, whose KB-29Ms were newly equipped with aerial refueling equipment purchased from the British firm FRL. The 43rd ARS, along with the 509th ARS at Walker AFB , New Mexico , was the first dedicated air refueling unit in history. On 2 March 1949,

2592-678: The University of Arizona in Tucson . After enlisting in the military in 1917, he was briefly assigned to Fort Hauchuca in Arizona before being transferred to College Station, Texas , to complete his academic studies. He returned to the military after graduation in 1918, assembling airplanes at Kelly Field in San Antonio, Texas . He trained pilots during the first World War , including some pilots who took down German planes. He reached

2688-532: The stiffness of one component can induce flutter in an apparently unrelated aerodynamic component. At its mildest, this can appear as a "buzz" in the aircraft structure, but at its most violent, it can develop uncontrollably with great speed and cause serious damage to the aircraft or lead to its destruction, as in Northwest Airlines Flight 2 in 1938, Braniff Flight 542 in 1959, or the prototypes for Finland's VL Myrsky fighter aircraft in

2784-423: The 355 FW, the 924 FG currently flies the same Fairchild Republic A-10 Thunderbolt II close air support aircraft. The 924 FG consists of the 47th Fighter Squadron (A-10C), 924th Maintenance Squadron, 924th Operational Support Flight. Between October 2013 and March 2014, the 924 FG transitioned from being a "classic" associate unit when it gained 28 A-10 aircraft of its own from Barksdale AFB , Louisiana. The 924th

2880-428: The 355 WG, equipped with HC-130 aircraft and HH-60 helicopters. At the same time, the 41st and 43d Electronic Combat Squadrons were realigned under the control of the 55th Electronic Combat Group (55 ECG). While personnel and aircraft remained on Davis–Monthan AFB, operational control of the 55 ECG was assumed by the 55th Wing at Offutt AFB , Nebraska . Another major wing realignment occurred on 1 October 2003, with

2976-979: The 355th Wing again realigned and now falls under the 15th Air Force Headquarters at Shaw AFB, SC . On 1 October 2021, the 418th Test and Evaluation Squadron was activated at David-Monthan to provide test and evaluation of new tactics, techniques and procedures for the EC-130H Compass Call and HC-130J Combat King II . The host wing at Davis–Monthan is the 355th Wing , which includes: The 355 OG consists of six squadrons and over 450 personnel employing A-10 aircraft and an AN/TPS-75 radar system. It provides war-fighters with forces for close air support (CAS), air interdiction (AI), forward air control (FAC), combat search and rescue (CSAR), ground-based tactical air control, and airbase operations. It also conducts all formal course directed aircraft initial qualification/ re-qualification training. All active duty aircraft assigned to Davis–Monthan Air Force Base carry

Bell XV-3 - Misplaced Pages Continue

3072-402: The 55 ECG unit employs its Lockheed EC-130H Compass Call aircraft worldwide in tactical air operations in war and other contingencies. It also provides initial and recurrent training to all EC-130H Compass Call pilots, navigators, electronic warfare officers, and aircrew. Two other major tenant units are assigned to the Air Force Reserve Command (AFRC). The 943rd Rescue Group (structured as

3168-704: The Afghan population as it struggled with its emergent democracy , and provided key support during national elections. While the 2003 deployment saw limited action, the Bulldogs employed over 22,000 rounds of 30 mm during 130 troops-in-contact situations during the 2005 deployment. Returning to Afghanistan in April 2007 for another six-month deployment, the 345th again provided 24-hour presence and Close Air Support expertise to coalition forces in support of Operation Enduring Freedom. During this period, insurgent activity level

3264-478: The Air Force's tactical air control system west of the Mississippi River transferred from Bergstrom Air Force Base , Texas, and stood up at D–M, bringing 16 OA-37B aircraft and numerous new personnel to the base. The 23rd TASS became the Air Force's first O/A-10 squadron in 1988, providing heavily armed airborne forward air control (FAC) capability for the first time. Unlike all other D–M aircraft at

3360-520: The Ames 40 × 80 wind tunnel. As the engineers were completing the last planned test, a wingtip failure caused both rotors to fail, resulting in severe damage of the XV-3 and damage to the wind tunnel. On 14 June 1966, NASA Ames Research Center announced the completion of XV-3 testing. The XV-3 had accomplished a total of 250 flights, accumulated 125 flight hours, and completed 110 full conversions. In late 1966,

3456-461: The Davis–Monthan until 1976, when the 100 SRW was inactivated, its DC-130s transferred to Tactical Air Command 's 432d Tactical Drone Group, and its U-2s transferred to SAC's 9th Strategic Reconnaissance Wing (9 SRW) at Beale Air Force Base , California , where U-2 Dragon Lady operations were consolidated with SR-71 Blackbird operations. On 15 June 1964, Davis–Monthan's 303d Bombardment Wing

3552-417: The United States, England, and Korea . During this period, the 602nd Tactical Air Control Wing deployed Airborne Forward Air Controllers in their OA-10 aircraft to Operation Desert Storm , providing nearly 100 percent of this capability to the war. On 1 October 1991, the 355 TTW was redesignated as the 355th Fighter Wing (355 FW) in tune with the Air Force's Objective Wing philosophy. The 355th Fighter Wing

3648-421: The activation of the 4105th Army Air Force Unit . The 4105th oversaw the storage of excess B-29s and C-47 "Gooney Birds." Tucson's low humidity and alkali soil made it an ideal location for aircraft storage and preservation, awaiting cannibalization or possible reuse—a mission that has continued to this day. The Cold War era was ushered in at Davis–Monthan on 21 March 1946, with the installation placed under

3744-533: The activation of the 563rd Rescue Group (563 RQG) on Davis–Monthan AFB. Control of the 48th, 55th, and 79th Rescue Squadrons (RQS) was passed to the new group with the 23rd Wing (23 WG) at Moody Air Force Base , Georgia assuming operational command of the unit. In 2003 and 2005, the 354th Fighter Squadron (354 FS) "Bulldogs" deployed on five-month deployments to Bagram Airfield in Afghanistan. During these deployments, they provided 24-hour presence to reassure

3840-442: The aircraft crashed when the test pilot blacked out due to extremely high cockpit vibrations. The vibrations resulted when the rotor shafts were moved 17 degrees forward from vertical. The test pilot, Dick Stansbury, was seriously injured, and the aircraft was damaged beyond repair. Bell modified the second XV-3 (serial number 54-148 ) by replacing the three-bladed rotors with two-bladed rotors, and after taking extensive precautions,

3936-406: The aircraft experienced a hard landing when the rotor developed dynamic instability. Bell attempted to remedy the situation, and flight testing resumed on 29 March 1956 after additional ground runs. Bell continued to expand the flight envelope of the XV-3, but on 25 July 1956, the same rotor instability occurred again. Flight testing of the XV-3 resumed in late September 1956. Then, on 25 October 1956,

Bell XV-3 - Misplaced Pages Continue

4032-533: The aircraft was disassembled and placed into indoor storage. On 22 January 2004, the XV-3 was delivered to Bell Plant 6 in Arlington, Texas. In 2005, Bell Helicopter employees began work to restore 54-148 to museum display condition, this time led by former XV-3 engineer Charles Davis. Following a two-year restoration, the XV-3 was transferred to the National Museum of the United States Air Force in Dayton, Ohio . It

4128-462: The base and assumed responsibility for all U-2 operations, emphasizing long-range strategic reconnaissance and intelligence collection. As a Strategic Air Command (SAC) unit, the 4080th was later redesignated the 100th Strategic Reconnaissance Wing and also acquired Lockheed DC-130 Hercules aircraft for launch and control of Firebee reconnaissance drones that were the precursors of contemporary unmanned aerial systems. The DC-130s and U-2s remained at

4224-411: The base became known as Davis–Monthan Army Air Field on 3 December 1941. U.S. Army Air Forces leaders then utilized the airfield for heavy bomber operation, sending Douglas B-18 Bolo , Consolidated B-24 Liberator , and Boeing B-29 Superfortress bombers, for training and observation missions. Among the bombardment groups trained at the base during the war: Training at the airfield came to

4320-610: The base. The base was named in honor of World War I pilots Lieutenants Samuel H. Davis (1896–1921) and Chief Engineer Oscar Monthan (1885–1924), both Tucson natives. Monthan enlisted in the Army as a private in 1917, was commissioned as a ground officer in 1918, and later became a pilot; he was killed in the crash of a Martin B2 bomber in Hawaii on March 27, 1924. First Lieutenant Samuel Howard Davis (November 20, 1896 – December 28, 1921)

4416-454: The claimancy of the recently established Strategic Air Command (SAC). SAC's presence at the base began in the form of the 40th and 444th Bombardment Groups, both equipped with B-29s. As part of the postwar austerity, these groups were later inactivated, with the personnel and equipment being consolidated into the 43d Bombardment Group in October. On 11 January 1948, with the establishment of

4512-461: The completion of the joint service testing, the aircraft was returned to the Ames facility, where on 12 August 1959, Fred Drinkwater became the first NASA test pilot to complete the full conversion of a tiltrotor to airplane mode. On 8 August 1961, Army Major E. E. Kluever became the first Army pilot to fly a tiltrotor aircraft. Testing would continue through July 1962 as NASA and Bell completed wind tunnel testing to study pitch-flap coupling exhibited by

4608-467: The course for one term, Kármán passed it over to Ernest Edwin Sechler , who developed aeroelasticity in that course and in publication of textbooks on the subject. In 1947, Arthur Roderick Collar defined aeroelasticity as "the study of the mutual interaction that takes place within the triangle of the inertial, elastic, and aerodynamic forces acting on structural members exposed to an airstream, and

4704-445: The early 1940s, when military requirements began to require the relocation of civil aviation activities. Davis–Monthan Airport became Tucson Army Air Field in 1940, as the United States prepared for World War II . The first assigned U.S. Army Air Corps units were the 1st Bomb Wing, 41st Bomb Group and 31st Air Base Group, activating on 30 April 1941 with Lieutenant Colonel Ames S. Albro Sr. as commanding officer. In its military role,

4800-508: The early 1940s. Famously, the original Tacoma Narrows Bridge was destroyed as a result of aeroelastic fluttering. In some cases, automatic control systems have been demonstrated to help prevent or limit flutter-related structural vibration. Propeller whirl flutter is a special case of flutter involving the aerodynamic and inertial effects of a rotating propeller and the stiffness of the supporting nacelle structure. Dynamic instability can occur involving pitch and yaw degrees of freedom of

4896-452: The external aerodynamic loads and the way they change but also the structural, damping and mass characteristics of the aircraft. Prediction involves making a mathematical model of the aircraft as a series of masses connected by springs and dampers which are tuned to represent the dynamic characteristics of the aircraft structure. The model also includes details of applied aerodynamic forces and how they vary. The model can be used to predict

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4992-552: The field began when Sergeant Simpson relocated his fuel and service operation to the site on 6 October 1927. He kept a log containing names of the field's customers, including Lindbergh, Amelia Earhart , Benjamin Foulois , and Jimmy Doolittle . Doolittle, awarded the Medal of Honor for his 1942 Tokyo raid , was the first military customer at the field on 9 October 1927. The combination of civil and military operations worked well until

5088-437: The flutter margin and, if necessary, test fixes to potential problems. Small carefully chosen changes to mass distribution and local structural stiffness can be very effective in solving aeroelastic problems. Methods of predicting flutter in linear structures include the p-method , the k-method and the p-k method . For nonlinear systems , flutter is usually interpreted as a limit cycle oscillation (LCO), and methods from

5184-417: The following aeroelastic problems: Aeroelasticity problems can be prevented by adjusting the mass, stiffness or aerodynamics of structures which can be determined and verified through the use of calculations, ground vibration tests and flight flutter trials . Flutter of control surfaces is usually eliminated by the careful placement of mass balances . The synthesis of aeroelasticity with thermodynamics

5280-426: The forward battle area and behind enemy lines. This capability added yet more strength to the wing's combat capability. The 43rd Electronic Combat Squadron "Bats" are part of the 55th Wing at Offutt AFB , Nebraska , but operate out of Davis–Monthan. In addition, the 42d Airborne Command and Control Squadron arrived from Keesler AFB , Mississippi on 19 July 1994. On 1 May 1992, senior Air Force leaders implemented

5376-433: The influence of this study on design". In an aeroplane, two significant static aeroelastic effects may occur. Divergence is a phenomenon in which the elastic twist of the wing suddenly becomes theoretically infinite, typically causing the wing to fail. Control reversal is a phenomenon occurring only in wings with ailerons or other control surfaces, in which these control surfaces reverse their usual functionality (e.g.,

5472-439: The initiation of three ongoing missions: Operation Enduring Freedom (OEF), Operation Iraqi Freedom (OIF), and Operation Noble Eagle (ONE). After Operation Enduring Freedom, eight A-10s from the 355 WG were called to Bagram Airfield , Afghanistan , to fly close air support missions supporting multinational ground forces. In September 2002, the 48th , 55th , and the 79th Rescue Squadron 's (RQS) transferred under control of

5568-571: The interactions between the inertial , elastic , and aerodynamic forces occurring while an elastic body is exposed to a fluid flow. The study of aeroelasticity may be broadly classified into two fields: static aeroelasticity dealing with the static or steady state response of an elastic body to a fluid flow, and dynamic aeroelasticity dealing with the body's dynamic (typically vibrational ) response. Aircraft are prone to aeroelastic effects because they need to be lightweight while enduring large aerodynamic loads. Aircraft are designed to avoid

5664-405: The lifting surface to move in the same direction and when it comes to point of divergence the structure deforms. Divergence can be understood as a simple property of the differential equation (s) governing the wing deflection . For example, modelling the airplane wing as an isotropic Euler–Bernoulli beam , the uncoupled torsional equation of motion is where y is the spanwise dimension, θ

5760-482: The most prominent tenant is the 309th Aerospace Maintenance and Regeneration Group (309 AMARG) of the Air Force Materiel Command (AFMC). As the main location for the 309 AMARG, Davis–Monthan AFB is the sole aircraft boneyard for excess military and U.S. government aircraft and other aerospace vehicles such as ballistic missiles. Tucson's dry climate and alkali soil make it an ideal location to store and preserve aircraft; more than 4,000 military aircraft are parked on

5856-615: The net damping decreases very suddenly, very close to the flutter point; and soft flutter , in which the net damping decreases gradually. In water the mass ratio of the pitch inertia of the foil to that of the circumscribing cylinder of fluid is generally too low for binary flutter to occur, as shown by explicit solution of the simplest pitch and heave flutter stability determinant. Structures exposed to aerodynamic forces—including wings and aerofoils, but also chimneys and bridges—are generally designed carefully within known parameters to avoid flutter. Blunt shapes, such as chimneys, can give off

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5952-486: The new Boeing B-47 Stratojet . The 303d Bombardment Wing , Medium, was initially established on 27 August 1951, and activated at Davis–Monthan AFB on 4 September 1951. The wing operated B-29s until January 1952, when it was equipped with KB-29s. On 20 January 1953, the 303d transitioned to the Boeing B-47 Stratojet for its three bomb squadrons, while an additional air refueling squadron equipped with KC-97s

6048-568: The newly established Air Combat Command (ACC) on the same date. Following Operation Desert Storm, the 355 WG supported Operation Southern Watch during deployments to Al Jaber, Kuwait, in 1997 by deploying 24 A-10s, in 1998 by deploying 16 A-10s, and in 1999 by deploying 14 A-10s—all to ensure compliance of the 33rd parallel southern no-fly zone. The flight and mysterious crash of Captain Craig D. Button took off from Davis–Monthan Air Force Base on 12 April 1997. The attacks on 11 September 2001, led to

6144-414: The policy of one base, one wing, one boss. The 836 AD and 602 TAIRCW inactivated (the later on 15 June 1992) while the 41 ECS and 43 ECS came under control of the 355 FW. With the mission diversified, the 355th Fighter Wing was re-designated as the 355th Wing (355 WG). On 1 June 1992, Tactical Air Command was inactivated and all aircraft, personnel and installations previously under TAC were transferred to

6240-489: The propeller and the engine supports leading to an unstable precession of the propeller. Failure of the engine supports led to whirl flutter occurring on two Lockheed L-188 Electra aircraft, in 1959 on Braniff Flight 542 and again in 1960 on Northwest Orient Airlines Flight 710 . Flow is highly non-linear in the transonic regime, dominated by moving shock waves. Avoiding flutter is mission-critical for aircraft that fly through transonic Mach numbers. The role of shock waves

6336-633: The rank of Second Lieutenant . Davis was honorably discharged from the military about 1919 with the rank of First Lieutenant in the reserve corps . For a time he worked commercial aviation as a manager with the Arizona Aviation Company, where he piloted Orioles and standard manufacture airplanes. Davis married Marjorie Cameron of San Antonio in 1920. Davis returned to the Army Air Service in August 1921. He died in

6432-538: The remaining aircraft was severely damaged in a wind tunnel accident on 20 May 1966. The data and experience from the XV-3 program were key elements used to successfully develop the Bell XV-15 , which later paved the way for the V-22 Osprey . The remaining prototype survived to the 21st century when it was restored by Bell, with a two-year restoration that included engineers that worked on the XV-3 originally. It

6528-446: The rolling direction associated with a given aileron moment is reversed). Divergence occurs when a lifting surface deflects under aerodynamic load in a direction which further increases lift in a positive feedback loop. The increased lift deflects the structure further, which eventually brings the structure to the point of divergence. Unlike flutter, which is another aeroelastic problem, instead of irregular oscillations, divergence causes

6624-523: The rotor controls were stiffened. The XV-3 resumed flight testing at Bell's facility on 12 December 1958. On 18 December 1958, Bell test pilot Bill Quinlan accomplished the first dynamically stable full conversion to airplane mode, and on 6 January 1959, Air Force Captain Robert Ferry became the first military pilot to complete a tiltrotor conversion to airplane mode. Flight testing at the Bell facilities

6720-415: The rotor pylons. On 6 May 1958, another instance of rotor instability occurred when the pylons were advanced to 40-degrees forward pylon angle, and the XV-3 was grounded once more. The XV-3 returned to the Ames wind tunnel in October 1958 to collect more data before it could be flown again. As a result of the wind tunnel testing, the rotor diameter was reduced, wing structure was increased and strengthened, and

6816-501: The second XV-3 began testing at the National Advisory Committee for Aeronautics ' (NACA) Ames Aeronautical Laboratory wind tunnel facility on 18 July 1957. Flight testing for aircraft #2 began on 21 January 1958 at Bell's facility. By April, the aircraft had expanded the flight envelope to 127 miles per hour (204 km/h) as well as demonstrating full autorotation landings and 30-degrees forward transitions with

6912-550: The site was declared a National Historic Landmark . In 1987, the 71st Special Operations Squadron , an Air Force Reserve unit flying HH-3 Jolly Green Giants, was activated at the base. While it served after the invasion of Kuwait in Desert Shield/Storm, it did not survive the end of the Cold War drawdown, and disbanded in 1992. In the 1990s, the 355 TTW continued to train A-10 crews for assignments to units in

7008-614: The sole remaining XV-3, serial number 54-148 , was moved to outside storage at Davis–Monthan Air Force Base in Tucson, Arizona. In 1984, the Bell XV-15 flight test team discovered the aircraft stored outside the Army's Aviation Museum during the XV-15 visit to Fort Rucker , Alabama, as part of a demonstration tour. 54-148 was repaired by December 1986, with Army support and the leadership of former Bell XV-3 engineer Claude Leibensberger, but

7104-485: The strategic modernization program, Titan II systems were to be retired by 1 October 1987. Deactivation began at Davis–Monthan on 1 October 1982. During the operation, titled "Rivet Cap", the missiles were removed and shipped to Norton AFB , California for refurbishment and storage. Explosive demolition began at the headworks of missile complex 570–7 on 30 November 1983. In May 1984, the 390 SMW's last Titan II at Davis–Monthan came off alert status. SAC subsequently inactivated

7200-534: The study of dynamical systems can be used to determine the speed at which flutter will occur. These videos detail the Active Aeroelastic Wing two-phase NASA - Air Force flight research program to investigate the potential of aerodynamically twisting flexible wings to improve maneuverability of high-performance aircraft at transonic and supersonic speeds, with traditional control surfaces such as ailerons and leading-edge flaps used to induce

7296-529: The subsequent investigation F. W. Lanchester was consulted. One of his recommendations was that left and right elevators should be rigidly connected by a stiff shaft, which was to subsequently become a design requirement. In addition, the National Physical Laboratory (NPL) was asked to investigate the phenomenon theoretically, which was subsequently carried out by Leonard Bairstow and Arthur Fage . In 1926, Hans Reissner published

7392-456: The tail code "DM". The 563rd Rescue Group is part of the 355th Wing. It includes the following squadrons: The 924 FG of the Air Force Reserve Command (AFRC) was reactivated in 2011 and initially assigned to Davis–Monthan AFB as an "associate" unit to the 355 FW flying the A-10 aircraft. As part of the Air Force Reserve Command, it is also a geographically separated unit (GSU) of AFRC's 944th Fighter Wing (944 FW) at Luke AFB , Arizona. Like

7488-462: The tiltrotor in an effort to predict and eliminate the aeroelastic dynamic rotor instability (referred to simply as pylon whirl ) that had caused problems throughout the program. In April 1966, Bell Helicopter aerodynamicist Dr. Earl Hall published an analysis of the XV-3 program data explaining the tiltrotor aircraft pylon whirl instability. In order to establish Hall's findings and develop a computer model, NASA agreed to conduct wind tunnel testing at

7584-566: The time, the 23rd TASS fleet's tail flash read "NF", for "Nail FAC"; the squadron's radio call sign was "Nail". In 1984, as a result of the first series of Strategic Arms Reduction Treaties START I between the United States and the Soviet Union, SAC began to decommission its Titan II missile system. In 1982, the 390 SMW began removing its 18 missiles and inactivating the associated sites in preparation for eventual demolition. In October 1981, President Ronald Reagan announced that, as part of

7680-430: The training location for pilots in the A-10; the base was redesignated the 355th Tactical Training Wing on 1 September 1979. The organization was later redesignated the 355th Fighter Wing since it includes operational, deployable A-10 squadrons in addition to its CONUS training mission The 1980s brought several diverse missions to D–M. The headquarters charged with overseeing them was now the 836th Air Division , which

7776-475: The twist. Davis%E2%80%93Monthan Air Force Base Davis–Monthan Air Force Base ( DM AFB ) ( IATA : DMA , ICAO : KDMA , FAA LID : DMA ) is a United States Air Force base 5 miles (4 nmi; 8 km) southeast of downtown Tucson, Arizona . It was established in 1925 as Davis–Monthan Landing Field . The host unit for Davis–Monthan AFB is the 355th Wing (355 WG) assigned to Twelfth Air Force (12AF), part of Air Combat Command (ACC). The base

7872-518: The unit transitioned into F-86Ds followed by a transition to F-86Ls in the fall of 1957. In the spring of 1959 the unit received Northrop F-89J interceptors which it flew for only a year when it transitioned into McDonnell F-101Bs . On 24 December 1964, the 15th FIS was inactivated. In 1962, the Strategic Air Command 's 390th Strategic Missile Wing (390 SMW) and its 18 Titan II ICBM sites around Tucson were activated. The 390 SMW

7968-484: Was XH-33 , classifying it as a helicopter , but its designation was changed to XV-3 in the convertiplane series. The designation was changed once again in 1962 to XV-3A when the V-prefix was changed to mean VTOL . The leading designers were Bob Lichten and Kenneth Wernicke . The first XV-3 (serial number 54-147 ) flew on 11 August 1955 with Bell Chief Test Pilot Floyd Carlson at the controls. On 18 August 1955,

8064-483: Was a pilot and United States Army Air Service officer. Born to Sam and Effie Davis in 1896 in Dyer County, Tennessee , Davis was known by his middle name, Howard. He attended public schools in Tucson. As a young man, his hobbies included horseback riding and shooting; he was a good marksman. Davis enrolled at Texas A&M College in 1915 as a student of mechanical engineering, having previously attended

8160-435: Was activated 1 January 1981. The AD advised Air Force component commanders and land forces on A-10 aircraft tactics, training, employment and readiness, and subordinate units participated in exercises such as Red Flag and Celtic Echo. The 41st Electronic Combat Squadron equipped with the EC-130H Compass Call aircraft, arrived on 1 July 1980, and reported to the 552d Airborne Warning and Control Wing . In 1981 D–M welcomed

8256-445: Was activated. As of October 2020, the 355 FW is composed of four groups: the 355th Operations Group (355 OG), the 355th Maintenance Group (355 MG), the 355th Mission Support Group (355 MSG), and the 355th Medical Group (355 MDG). Along with their tenant organizations, they make up the 6,100 airmen and 1,700 civilian personnel at Davis–Monthan AFB. The 355th Fighter Wing was re-designated 355th Wing on January 2, 2019. On 20 August 2020,

8352-547: Was assigned to the wing between 18 February 1953, and 1 February 1956. A standard SAC Alert Area ramp was constructed in the southeast corner of the base adjacent to the runway and the 303d assumed nuclear alert responsibilities when final conversion and checkout in the B-47 was complete. In April 1953, the Air Defense Command 's (ADC) 15th Fighter-Interceptor Squadron was activated with F-86A Sabres . A year later,

8448-438: Was completed on 24 April 1959, and the aircraft was shipped to Edwards Air Force Base. The military flight testing of the XV-3 began on 14 May 1959. Promoted to the rank of Major, Robert Ferry would coauthor the report on the military flight evaluations, conducted from May to July 1959, noting that despite the deficiencies of the design, the "fixed-wing tilt-prop," or tiltrotor, was a practical application for rotorcraft. Following

8544-428: Was composed of the 355th Operations Group (355 OG), the 355th Maintenance Group (355 MG), the 355th Medical Group (355 MDG), and the 355th Mission Support Group (355 MSG). In May 1992, the 41st and 43d Electronic Combat Squadrons , flying EC-130H Hercules Compass Call arrived. The aircraft carried an airborne battlefield command and control center capsule that provides continuous control of tactical air operations in

8640-527: Was first analyzed by Holt Ashley . A phenomenon that impacts stability of aircraft known as "transonic dip", in which the flutter speed can get close to flight speed, was reported in May 1976 by Farmer and Hanson of the Langley Research Center . Buffeting is a high-frequency instability, caused by airflow separation or shock wave oscillations from one object striking another. It is caused by

8736-693: Was inactivated as part of the retirement of the B-47 Stratojet from active service. The year 1964 brought back the combat crew training mission of the World War II years with the 4453d Combat Crew Training Wing of the Tactical Air Command equipped with the Air Force's newest and most sophisticated fighter, the McDonnell Douglas F-4 Phantom II . In July 1971, the 355th Tactical Fighter Wing , flying

8832-647: Was one of only three Titan II missile wings in SAC and represented the heaviest land-based missile and the largest single warhead ever fielded by U.S. strategic deterrent forces. In July 1963, the 4028th Strategic Reconnaissance Weather Wing , equipped with U-2 strategic reconnaissance aircraft, began flying global missions from Davis–Monthan. Following the Cuban Missile Crisis in 1963, the 4080th Strategic Reconnaissance Wing at Laughlin AFB , Texas, relocated to

8928-510: Was placed on display in the museum's Post-Cold War Gallery in June 2007, and as of 2011 is on display in the Research & Development Gallery. Data from NASA Monograph 17 and Aerophile, Vol. 2, No. 1. General characteristics Performance Related development Related lists Aeroelastic flutter Aeroelasticity is the branch of physics and engineering studying

9024-549: Was survived by his widow, his parents, and a brother, Wilton. Davis's father was in attendance at the 1925 dedication of the base, as was Governor G.W.P. Hunt , who spoke at the dedication. In 1919, the Tucson Chamber of Commerce aviation committee established the nation's first municipally owned airfield at the current site of the Tucson Rodeo Grounds. The rapid increase in aviation activities meant

9120-481: Was the highest recorded to date in OEF. The Bulldogs employed an unprecedented number of munitions during this deployment—over 150,000 rounds of 30 mm in support of over 400 troops-in-contact situations. On 26 April 2007, the 355th Wing was re-designated as the 355th Fighter Wing (355 FW) with only A-10 fighter aircraft assigned. Also in 2007, the 214th Reconnaissance Group (214 RG), an Arizona Air National Guard unit,

9216-581: Was then transferred to the National Museum of the United States Air Force in Dayton, Ohio , where it was put on display. In 1951, the Army and Air Force announced the Convertible Aircraft Program and released the Request for Proposals (RFP) to solicit designs from the aircraft industry. In October 1953, Bell Helicopter was awarded a development contract to produce two aircraft for testing purposes. The original military designation

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