High Alpha Research Vehicle

Last updated
F-18 High Alpha Research Vehicle (HARV)
FA18 LEX.jpg
F-18 HARV in high alpha maneuver
RoleTest aircraft
Manufacturer McDonnell Douglas
StatusPrototype from military service
Primary user NASA
Number built1
Developed from McDonnell Douglas F/A-18 Hornet

The High Alpha Research Vehicle was a modified American McDonnell Douglas F/A-18 Hornet used by NASA in a three-phase program investigating controlled flight at high alpha (angle of attack) using thrust vectoring, modifications to the flight controls, and with actuated forebody strakes. The program lasted from April 1987 to September 1996. [1] [2]

Contents

NASA reported that in one phase of the project, Armstrong Flight Research Center "research pilots William H. "Bill" Dana and Ed Schneider completed the envelope expansion flights in February 1992. Demonstrated capabilities included stable flight at approximately 70 degrees angle of attack (previous maximum was 55 degrees) and rolling at high rates at 65 degrees angle of attack. Controlled rolling would have been nearly impossible above 35 degrees without vectoring." [3] Performance figures were not listed for other phases.

The aircraft is now on display at the Virginia Air and Space Center in Hampton, Virginia. [4]

See also

Related Research Articles

<span class="mw-page-title-main">McDonnell Douglas F/A-18 Hornet</span> Carrier-capable multirole strike aircraft

The McDonnell Douglas F/A-18 Hornet is an all-weather supersonic, twin-engine, carrier-capable, multirole combat aircraft, designed as both a fighter and attack aircraft. Designed by McDonnell Douglas and Northrop, the F/A-18 was derived from the latter's YF-17 in the 1970s for use by the United States Navy and Marine Corps. The Hornet is also used by the air forces of several other nations, and formerly by the U.S. Navy's Flight Demonstration Squadron, the Blue Angels.

For fixed-wing aircraft, ground effect is the reduced aerodynamic drag that an aircraft's wings generate when they are close to a fixed surface. Reduced drag when in ground effect during takeoff can cause the aircraft to "float" while below the recommended climb speed. The pilot can then fly just above the runway while the aircraft accelerates in ground effect until a safe climb speed is reached.

<span class="mw-page-title-main">Stall (fluid dynamics)</span> Abrupt reduction in lift due to flow separation

In fluid dynamics, a stall is a reduction in the lift coefficient generated by a foil as angle of attack increases. This occurs when the critical angle of attack of the foil is exceeded. The critical angle of attack is typically about 15°, but it may vary significantly depending on the fluid, foil, and Reynolds number.

<span class="mw-page-title-main">Angle of attack</span> Angle between the chord of a wing and the undisturbed airflow

In fluid dynamics, angle of attack is the angle between a reference line on a body and the vector representing the relative motion between the body and the fluid through which it is moving. Angle of attack is the angle between the body's reference line and the oncoming flow. This article focuses on the most common application, the angle of attack of a wing or airfoil moving through air.

<span class="mw-page-title-main">Leading-edge extension</span> Anti-stall control surface on aircraft

A leading-edge extension (LEX) is a small extension to an aircraft wing surface, forward of the leading edge. The primary reason for adding an extension is to improve the airflow at high angles of attack and low airspeeds, to improve handling and delay the stall. A dog tooth can also improve airflow and reduce drag at higher speeds.

<span class="mw-page-title-main">Northrop YF-17</span> Prototype fighter aircraft for the US military

The Northrop YF-17 is a prototype lightweight fighter aircraft designed by Northrop aviation for the United States Air Force's Lightweight Fighter (LWF) technology evaluation program. The LWF was initiated because many in the fighter community believed that aircraft like the F-15 Eagle were too large and expensive for many combat roles. The YF-17 was the culmination of a long line of Northrop designs, beginning with the N-102 Fang in 1956, continuing through the F-5 family.

<span class="mw-page-title-main">Grumman X-29</span> 1984 experimental aircraft family by Grumman

The Grumman X-29 was an American experimental aircraft that tested a forward-swept wing, canard control surfaces, and other novel aircraft technologies. The X-29 was developed by Grumman, and the two built were flown by NASA and the United States Air Force. The aerodynamic instability of the X-29's airframe required the use of computerized fly-by-wire control. Composite materials were used to control the aeroelastic divergent twisting experienced by forward-swept wings, and to reduce weight. The aircraft first flew in 1984, and two X-29s were flight tested through 1991.

<span class="mw-page-title-main">Rockwell-MBB X-31</span> Type of aircraft

The Rockwell-Messerschmitt-Bölkow-Blohm X-31 is an experimental jet fighter designed to test fighter thrust vectoring technology.

<span class="mw-page-title-main">Thrust vectoring</span> Facet of ballistics and aeronautics


Thrust vectoring, also known as thrust vector control (TVC), is the ability of an aircraft, rocket, or other vehicle to manipulate the direction of the thrust from its engine(s) or motor(s) to control the attitude or angular velocity of the vehicle.

<span class="mw-page-title-main">William H. Dana</span> NASA research pilot and astronaut

William Harvey Dana was an American aeronautical engineer, U.S. Air Force pilot, NASA test pilot, and astronaut. He was one of twelve pilots who flew the North American X-15, an experimental spaceplane jointly operated by the Air Force and NASA. He was also selected for participation in the X-20 Dyna-Soar program.

<span class="mw-page-title-main">Scaled Composites ARES</span> Type of aircraft

The Scaled Composites ARES is a demonstrator aircraft built by Scaled Composites. ARES is an acronym for Agile Responsive Effective Support.

<span class="mw-page-title-main">Vortex lift</span> Lift from highly sweptback aircraft wings

Vortex lift is that portion of lift due to the action of leading edge vortices. It is generated by wings with highly sweptback, sharp, leading edges or highly-swept wing-root extensions added to a wing of moderate sweep. It is sometimes known as non-linear lift due to its rapid increase with angle of attack. and controlled separation lift, to distinguish it from conventional lift which occurs with attached flow.

<span class="mw-page-title-main">McDonnell Douglas F-15 STOL/MTD</span> USAF/NASA R&D aircraft

The McDonnell Douglas F-15 STOL/MTD is a modified F-15 Eagle. Developed as a technology demonstrator, the F-15 STOL/MTD carried out research for studying the effects of thrust vectoring and enhanced maneuverability. The aircraft used for the project was pre-production TF-15A (F-15B) No. 1, the first two-seat F-15 Eagle built by McDonnell Douglas, the sixth F-15 off the assembly line, and was the oldest F-15 flying up to its retirement. It was also used as the avionics testbed for the F-15E Strike Eagle program. The plane was on loan to NASA from the United States Air Force.

<span class="mw-page-title-main">Boeing X-53 Active Aeroelastic Wing</span> Experimental aircraft

The X-53 Active Aeroelastic Wing (AAW) development program is a completed American research project that was undertaken jointly by the Air Force Research Laboratory (AFRL), Boeing Phantom Works and NASA's Dryden Flight Research Center, where the technology was flight tested on a modified McDonnell Douglas F/A-18 Hornet. Active Aeroelastic Wing Technology is a technology that integrates wing aerodynamics, controls, and structure to harness and control wing aeroelastic twist at high speeds and dynamic pressures. By using multiple leading and trailing edge controls like "aerodynamic tabs", subtle amounts of aeroelastic twist can be controlled to provide large amounts of wing control power, while minimizing maneuver air loads at high wing strain conditions or aerodynamic drag at low wing strain conditions. This program was the first full-scale proof of AAW technology.

<span class="mw-page-title-main">Christopher Loria</span>

Christopher Joseph "Gus" Loria is a retired United States Marine Corps Colonel and a medically retired NASA astronaut. He was originally scheduled to fly on STS-113 as pilot; however, he was grounded from spaceflight due to a severe back injury.

<span class="mw-page-title-main">Mercedes Reaves</span> Puerto Rican electronics engineer

Mercedes Reaves is a Puerto Rican research engineer and scientist. She is responsible for the design of a viable full-scale solar sail and the development and testing of a scale model solar sail at NASA Langley Research Center in Virginia.

Supermaneuverability is the capability of fighter aircraft to execute tactical maneuvers that are not possible with purely aerodynamic techniques. Such maneuvers can involve controlled side-slipping or angles of attack beyond maximum lift.

The propulsive wing is a patented UAV design concept developed in the 2000s with extremely high lift and internal volume. The propulsive wing could be used to develop a new class of aircraft based on an embedded, distributed cross-flow fan propulsion system within a thick wing. The fan, partially embedded within the airfoil section, draws the flow in from the suction surface and exhausts at the trailing edge. In cruise, the combination of distributed boundary-layer ingestion and wake filling increase propulsive efficiency, while distributed vectored thrust provides substantial improvements in pressure drag.

Flight dynamics in aviation and spacecraft, is the study of the performance, stability, and control of vehicles flying through the air or in outer space. It is concerned with how forces acting on the vehicle determine its velocity and attitude with respect to time.

References

  1. Jenkins, Dennis R. (2000). F/A-18 Hornet: A Navy Success Story . New York: McGraw-Hill. ISBN   0-07-134696-1.
  2. F-18 High Alpha Research Vehicle (HARV) fact sheet, NASA/Dryden Flight Research Center.
  3. NASA Past Projects: F-18 High Alpha Research Vehicle, NASA
  4. "Virginia Air and Space Center to Dedicate NASA F-18 Research Jet" . Retrieved 12 October 2018.

Further reading