The Dyna-Soar was developed by Boeing and resembled a small, winged aircraft with heat-resistant materials to withstand the intense heat of re-entry into Earth’s atmosphere. It was designed to be launched atop a powerful booster rocket, like the Titan III, and then maneuver in space before returning to Earth. Unlike traditional capsules of the time, the Dyna-Soar’s design allowed it to land on a runway, giving it unique versatility.

Despite its innovative design, the Dyna-Soar faced numerous challenges, including technical difficulties, high costs, and a lack of a clear mission as NASA’s focus shifted towards manned lunar exploration. In 1963, after spending over $660 million on the project, the U.S. government canceled the Dyna-Soar, favoring other space endeavors such as the Gemini program.

Though it never flew, the Dyna-Soar was an important step in aerospace development. Its concept influenced later spaceplane designs, including the Space Shuttle, highlighting the early vision of reusable spacecraft that would come to shape the future of human spaceflight.

Document Archive

Strangled Infant: The Boeing X-20A Dyna-Soar by Clarence Geiger, Date Unknown [214 Pages, 4MB]

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Introduced in the early 1950s, the Bell X-5 was instrumental in exploring the aerodynamic implications of variable-sweep wing designs. The primary aim was to assess how different wing configurations affected performance during various phases of flight, such as takeoff, cruise, and landing. The X-5 had a range of sweep from 20 degrees to 60 degrees. This adjustability showcased a significant advancement in aviation technology, suggesting that aircraft could be designed to perform optimally at both high speeds and slow speeds without compromising on stability or control.

The X-5 was powered by an Allison J35 turbojet engine, which provided the necessary thrust to explore high-speed performance. Measuring just over 33 feet in length and with a wingspan that varied depending on the sweep of its wings, the X-5 was relatively compact. Its design included a traditional tailplane and a bubble canopy that offered pilots excellent visibility.

During its operational lifetime, the Bell X-5 provided invaluable data that informed the development of several later aircraft with variable geometry wings, most notably the General Dynamics F-111 and the Grumman F-14 Tomcat. Both of these aircraft utilized technology that had been directly evolved from the experiments conducted with the X-5. The ability to alter wing sweep in flight allowed these aircraft to excel at high-speed intercepts and provide considerable fuel efficiency during longer, slower missions.

However, the X-5 was not without challenges. It demonstrated the complexity and potential dangers of variable-sweep wing technology. On several occasions, issues with the wing sweep mechanism led to accidents, including one fatal crash. These incidents underscored the importance of rigorous testing and refinement of the technology.

Despite these challenges, the Bell X-5 marks a significant chapter in aviation history. It was a critical step forward in the exploration of wing geometries and their effects on aircraft performance. The lessons learned from the X-5’s testing phase have echoed throughout aircraft design principles for decades, proving that its contributions to aerospace engineering and technology were both profound and enduring. The Bell X-5 not only tested the boundaries of aviation technology but also set the stage for future innovations that continue to influence the aerospace industry today.

Document Archive

 The Bell X-5 Research Plane, Date Unknown [65 Pages, 23MB] – My father, John Greenewald, Sr., got these documents from Edwards AFB. My grandfather, R.E. Greenewald, worked on the Bell X-5. Also included in this PDF is an article entitled “Swing Wing, The Bell X-5” from 1993.

 Flight Test, Research Airplane, Rocket Propelled, High Speed – Report No. 58-947-010 [67 Pages, 23MB] – My father, John Greenewald, Sr., got these documents (also included is a document on the Bell X-1) from Edwards AFB. My grandfather, R.E. Greenewald, worked on both aircraft.

 The Bell X-5 Research Aircraft, 27 July 1989 [67 Pages, 42MB]

The post Bell X-5 first appeared on The Black Vault.

Note: The following is a press release sent out by the  Defense Advanced Research Projects Agency (DARPA) on January 17, 2023, and is archived here for reference purposes.

DARPA has selected Aurora Flight Sciences to move into the detailed design phase of the Control of Revolutionary Aircraft with Novel Effectors (CRANE) program. This follows successful completion of the project’s Phase 1 preliminary design, which resulted in an innovative testbed aircraft that used active flow control (AFC) to generate control forces in a wind tunnel test. Phase 2 will focus on detailed design and development of flight software and controls, culminating in a critical design review of an X-plane demonstrator that can fly without traditional moving flight controls on the exterior of the wings and tail.

The contract includes a Phase 3 option in which DARPA intends to fly a 7,000-pound X-plane that addresses the two primary technical hurdles of incorporation of AFC into a full-scale aircraft and reliance on it for controlled flight. Unique features of the demonstrator aircraft will include modular wing configurations that enable future integration of advanced technologies for flight testing either by DARPA or potential transition partners.

“Over the past several decades, the active flow control community has made significant advancements that enable the integration of active flow control technologies into advanced aircraft. We are confident about completing the design and flight test of a demonstration aircraft with AFC as the primary design consideration,” said the CRANE Program Manager Richard Wlezien. “With a modular wing section and modular AFC effectors, the CRANE X-plane has the potential to live on as a national test asset long after the CRANE program has concluded.”

The AFC suite of technologies enables multiple opportunities for aircraft performance improvements, such as elimination of moving control surfaces, drag reduction and high angle of attack flight, thicker wings for structural efficiency and increased fuel capacity, and simplified high-lift systems.

“Thanks to a variety of innovative participants, the CRANE program has significantly advanced the state of the art of multiple active flow control technologies,” said Wlezien. “We are uniquely positioned to build on those achievements by evaluating a wide range of relevant technologies during our planned X-plane flight tests.”

The post DARPA Selects Aurora Flight Sciences for Phase 2 of Active Flow Control X-Plane first appeared on The Black Vault.

This sampling of newly released saucer-type aircraft documents contain detailed technical data and drawings related to the work undertaken by AVRO Aircraft Limited for the Air Force under Project 1794.

Project 1794 was interested in designing and testing a proposed supersonic vertical take-off and landing saucer type aircraft in 1957-58.

The Air Force Declassification Office declassified these documents in June 2001 and the National Declassification Center, National Archives, just recently approved them for public release.

Below are direct links to four documents.

Declassified Documents

Project Planning Report Project 1794, February 1957 [124 Pages, 22.6MB ]

Project Planning Report Project 1794 Final Development Report, 2 April – 30 May 1956 [116 Pages, 29.8MB]

Special Projects Group Technical Report No. 112, September 1957 [217 Pages, 15.3MB]

Untitled Project 1794 Report, Date Unknown [37 Pages, 4.75MB]

The post Project 1794 (Saucer-Type Aircraft) first appeared on The Black Vault.

Project Silver Bug was the American “Black” project version of the Avro Aircraft Canada Y-2 undertaken by the United States Air Force in 1953.

Declassified Documents

Project Silver Bug Technical Report

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Introduction

The NASA AD-1 was both an aircraft and an associated flight test program conducted between 1979 and 1982 at the NASA Dryden Flight Research Center, Edwards California, which successfully demonstrated an aircraft wing that could be pivoted obliquely from zero to 60 degrees during flight.

The unique oblique wing was demonstrated on a small, subsonic jet-powered research aircraft called the AD-1 (Ames Dryden -1). The aircraft was flown 79 times during the research program, which evaluated the basic pivot-wing concept and gathered information on handling qualities and aerodynamics at various speeds and degrees of pivot.

Thinking Obliquely: Robert T. Jones, the Oblique Wing, NASA’s AD-1 Demonstrator, and its Legacy

By Bruce I. Larrimer

On December 21, 1979, the National Aeronautics and Space Administration (NASA) AD-1 Oblique Wing Research Aircraft (OWRA) took off from the main runway at Edwards Air Force Base (AFB), CA, for a 45-minute checkout flight. It marked the world’s first flight of a piloted oblique-wing airplane. This historic flight, which was flown with the airplane’s wing at its “straight” (0-degree angle) position, was soon followed by flights at wing angles of 15 degrees, 20 degrees, 45 degrees, and finally on April 24, 1981, at the 60-degree-angle design goal, thus proving the aerodynamic concept of an airplane with an oblique-wing configuration. This initial oblique-wing program, which ran from 1976 through 1982, was a joint effort between NASA’s Ames Research Center and Dryden Flight Research Center, CA, thus giving rise to the aircraft’s name: Ames-Dryden AD-1 Oblique Wing Research Aircraft.

Chapter 1 reviews the life of NASA aerodynamicist Robert T. Jones and his path to the oblique wing. Chapter 2 covers the extensive wind tunnel, model, computer-code, and simulation testing, first at Langley and later at Ames, as well as a number of NASA industry design contracts undertaken by Boeing and Lockheed. Chapter 3 reviews the design and fabrication of the AD-1 Oblique Wing Research Aircraft and its subsequent proposed use as a joined-wing demonstrator. Chapter 4 describes the flight testing and flight evaluation of the AD-1. Chapter 5 reviews the supersonic F-8 followup oblique-wing program. And, finally, chapter 6 reviews the subsequent oblique-wing plans and proposals. Appendices present the physical characteristics of the AD-1 aircraft, a detailed description of it, and a summary flight log of its flight research program.

 Download Thinking Obliquely: Robert T. Jones, the Oblique Wing, NASA’s AD-1 Demonstrator, and its Legacy [278 Pages, 3.36MB]

NASA – NASA Dryden Fact Sheet – Ames-Dryden-1 (AD-1)

Ames-Dryden-1 (AD-1)

A program conducted between 1979 and 1982 at the NASA Dryden Flight Research Center, Edwards, CA, successfully demonstrated an aircraft wing that could be pivoted obliquely from zero to 60 degrees during flight.

The unique wing was demonstrated on a small, subsonic jet-powered research aircraft called the Ames Dryden -1 (AD-1). The aircraft was flown 79 times during the research program, which evaluated the basic pivot-wing concept and gathered information on handling qualities and aerodynamics at various speeds and degrees of pivot.

Program Background

The oblique wing concept originated with Robert T. Jones, an aeronautical engineer at NASA’s Ames Research Center, Moffett Field, CA. Analytical and wind tunnel studies Jones initiated at Ames indicated that a transport-size oblique-wing aircraft, flying at speeds up to Mach 1.4 (1.4 times the speed of sound), would have substantially better aerodynamic performance than aircraft with more conventional wings.

At high speeds, both subsonic and supersonic, the wing would be pivoted at up to 60 degrees to the aircraft’s fuselage for better high-speed performance. The studies showed these angles would decrease aerodynamic drag, permitting increased speed and longer range with the same fuel expenditure.

At lower speeds, during takeoffs and landings, the wing would be perpendicular to the fuselage like a conventional wing to provide maximum lift and control qualities. As the aircraft gained speed, the wing would be pivoted to increase the oblique angle, thereby reducing the drag and decreasing fuel consumption. The wing could only be swept in one direction, with the right wingtip moving forward.

The Aircraft

The AD-1 aircraft was delivered to Dryden in February 1979. The Ames Industrial Co., Bohemia, NY, constructed it, under a $240,000 fixed-price contract. NASA specified the overall vehicle design using a geometric configuration studied by the Boeing Commercial Airplane Company, Seattle, WA. The Rutan Aircraft Factory, Mojave, CA, provided the detailed design and load analysis for the intentionally low-speed, low-cost airplane. The low speed and cost of course limited the complexity of the vehicle and the scope of its technical objectives.

Piloting the aircraft on its first flight Dec. 21, 1979, was NASA research pilot Thomas C. McMurtry, who was also the pilot on the final flight Aug. 7, 1982. Powered by two small turbojet engines, each producing 220 pounds of static thrust at sea level, the aircraft was limited for reasons of safety to a speed of about 170 mph.

The AD-1 was 38.8 feet in length and had a wingspan of 32.3 feet unswept. It was constructed of plastic reinforced with fiberglass, in a sandwich with the skin separated by a rigid foam core. It had a gross weight of 2,145 lb, and an empty weight of 1,450 lb.

A fixed tricycle landing gear, mounted close to the fuselage to lessen aerodynamic drag, gave the aircraft a very “squatty” appearance on the ground. It was only 6.75 feet high. The wing was pivoted by an electrically driven gear mechanism located inside the fuselage, just forward of the engines.

Flight Research

The research project to validate the oblique wing concept was typical of any NASA high-risk project — to advance through each test element and expand the operating envelope, methodically and carefully. The basic purpose of the AD-1 project was to investigate the low-speed characteristics of an oblique-wing configuration.

The AD-1 made its first flight late in 1979. The wing was pivoted incrementally over the next 18 months until the full 60-degree angle was reached in mid-198l. The aircraft continued to be flown for another year, obtaining data at various speeds and wing-pivot angles until the final flight in August 1982. The final flight of the AD-1 did not occur at Dryden, however, but at the Experimental Aircraft Association’s (EAA) annual exhibition at Oshkosh, WI, where it was flown eight times to demonstrate its unique configuration.

Following the flight research, Jones still considered the oblique wing as a viable lift concept for large transoceanic or transcontinental transports. This particular low-speed, low-cost research vehicle, however—, as expected, —exhibited aeroelastic and pitch-roll-coupling effects that contributed to poor handling qualities at sweep angles above 45 degrees. The fiberglass structure limited wing stiffness that would have improved the aircraft’s handling qualities, as an improved (and thus more expensive) control system would also have done.

Thus, although the AD-1 structure allowed completion of the project’s technical objectives, there was still a need for a transonic oblique-wing research airplane to assess the effects of compressibility, evaluate a more representative structure, and analyze flight performance at transonic speeds (those on either side of the speed of sound).

Sources

“AD-1 Construction Completed,” Dryden X-Press, Feb. 23, 1979, p. 2.

Robert E. Curry and Alex G. Sim, “In-Flight Total Forces, Moments, and Static Aeroelastic Characteristics of an Oblique-Wing Research Airplane” (Edwards, CA: NASA TP-2224, 1984).

Robert E. Curry and Alexander G. Sim, “The Unique Aerodynamic Characteristics of the AD-1 Oblique-Wing Research Airplane,” AIAA paper 82-1329 presented at the AIAA 9th Atmospheric Flight Mechanics Conference, Aug. 9-11, 1982, San Diego, CA.

Flight logs for the AD-1 in the NASA Dryden Historical Reference Collection.

Thomas C. McMurtry, A. G. Sim, and W. H. Andrews, “AD-1 Oblique Wing Aircraft Program,” AIAA paper 81-2354 presented at the AIAA/SETP/SFTE/ASE/ITEA/IEEE 1st Flight Testing Conference, Nov. 11-13, 1981, Las Vegas, NV.

Alex G. Sim and Robert E. Curry, “Flight Characteristics of the AD-1 Oblique-Wing Research Aircraft,” (Edwards, CA: NASA TP-2223, 1985).

Alex G. Sim and Robert E. Curry, “Flight-Determined Aerodynamic Derivatives of the AD-1 Oblique-Wing Research Airplane” (Edwards, CA: NASA TP-2222, 1984).

The post NASA’s AD-1 Demonstrator first appeared on The Black Vault.

The VZ-9-AV Avrocar (official designation but often listed as VZ-9) was a Canadian VTOL aircraft developed by Avro Aircraft Ltd. as part of a secret U.S. military project carried out in the early years of the Cold War.

The Avrocar intended to exploit the Coandă effect to provide lift and thrust from a single “turborotor” blowing exhaust out the rim of the disk-shaped aircraft to provide anticipated VTOL-like performance. In the air, it would have resembled a flying saucer.

Two prototypes were built as “proof-of-concept” test vehicles for a more advanced USAF fighter and also for a U.S. Army tactical combat aircraft requirement. In flight testing, the Avrocar proved to have unresolved thrust and stability problems that limited it to a degraded, low-performance flight envelope; subsequently, the project was cancelled in 1961.

Declassified Documents

The Avrocar Flight Test Plan, 15 July 1959 [14 Pages, 1mb]

 Analysis of Tests of the Avrocar in the NASA 40 x 80ft Wind Tunnel, Ames Research Center, February 1961 [298 Pages, 187MB] – An analysis is presented of some aspects of the full scale wind tunnel tests of the Avrocar vehicle. Methods used to analyze force and pressure data are formulated and results are compared with theory and small scale model tests. Aerodynamically, the performance demonstrated by the first Avrocar vehicle in its initial configuration was disappointing in that a low lift curve slop, a large nose-up pitching moment and insufficient jet vectoring capability precluded flight in free air and in the ground cushion above about 35 mph. Modifications to the aircraft based on these and other test results have been made, the major change being in the redesign of the trailing edge region where a rearwardfacing nozzle, containing a pitch control vane to provide adequate jet vectoring control, has been incorporated. The jet flap effect thus obtained is expected to allow flight in free-air as well as at higher speeds in the ground cushion.

History of the Air Force Flight Test Center, Edwards Air Force Base, California, 1 January – 30 June 1961 [4 Pages, 1.69mb] – This is a partial release of this document, which includes only the portion on the Avrocar and the title page.

The post Avrocar first appeared on The Black Vault.