Pelikan tail

Last updated
Pelikan tail design Tail pelikan.svg
Pelikan tail design

The Pelikan tail is an experimental tail design for fighter jets. It was originally conceived by Ralph Pelikan, [1] who was hired by McDonnell Aircraft, later worked for McDonnell Douglas after the merger of McDonnell with Douglas and, after another merger, retired from Boeing. The concept was used in the Northrop YF-23 fighter. However, it has been considered or included in design specifications in the McDonnell Douglas BAE Joint Strike fighter (JSF) design which was eliminated before prototype stage [2] [3]

Contents

Advantages and disadvantages

The Pelikan design differs from the typical layout of flight control surfaces and empennage (incorporating ailerons on the wing, a horizontal stabilizer with elevators and a vertical stabilizer with a rudder), in that it uses only two moveable surfaces in order to achieve control of pitch, yaw and roll. When evaluated by Boeing engineers in October 1998 while designing what became the X-32, they found advantages of greater pitch control at high angles of attack and that two tail surfaces would have a lower radar signature than the four surfaces eventually adopted. [1] [2] However, they also found that using two larger control surfaces instead of four might actually make the aircraft heavier. The bigger hydraulic pumps and cylinders needed to operate the larger surfaces would add 800 to 900 pounds (360 to 410 kg) of weight to the design. [1] This and other factors made them use a four-surface tail instead. [1]

Tests by Virginia Tech students

Virginia Tech students built a model aircraft with a Pelikan tail and got positive results for its viability using a wind tunnel. [4] The analysis by the students found several advantages such as a lower vertical surface area, which aids in stealth; less drag due to skin friction; and a lower weight due to the need for two as opposed to the usual four hydraulic actuators.[ failed verification ] [5]

See also

Related Research Articles

<span class="mw-page-title-main">Tailplane</span> Small lifting surface of a fixed-wing aircraft

A tailplane, also known as a horizontal stabilizer, is a small lifting surface located on the tail (empennage) behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed-wing aircraft such as helicopters and gyroplanes. Not all fixed-wing aircraft have tailplanes. Canards, tailless and flying wing aircraft have no separate tailplane, while in V-tail aircraft the vertical stabilizer, rudder, and the tail-plane and elevator are combined to form two diagonal surfaces in a V layout.

<span class="mw-page-title-main">Flying wing</span> Tailless fixed-wing aircraft that has no definite fuselage

A flying wing is a tailless fixed-wing aircraft that has no definite fuselage, with its crew, payload, fuel, and equipment housed inside the main wing structure. A flying wing may have various small protuberances such as pods, nacelles, blisters, booms, or vertical stabilizers.

<span class="mw-page-title-main">T-tail</span> Aircraft empennage configuration

A T-tail is an empennage configuration in which the tailplane of an aircraft is mounted to the top of the fin. The arrangement looks like the capital letter T, hence the name. The T-tail differs from the standard configuration in which the tailplane is mounted to the fuselage at the base of the fin.

<span class="mw-page-title-main">V-tail</span> Aircraft tail that incorporates rudder and elevators in a V shape

The V-tail or vee-tail of an aircraft is an unconventional arrangement of the tail control surfaces that replaces the traditional vertical and horizontal surfaces with two surfaces set in a V-shaped configuration. It is not widely used in aircraft design. The aft edge of each twin surface is a hinged control surface called a ruddervator, which combines the functions of both a rudder and elevator.

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

The Northrop YF-17 was 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">Northrop YF-23</span> Prototype demonstrator aircraft for the U.S. Air Force Advanced Tactical Fighter program

The Northrop/McDonnell Douglas YF-23 is an American single-seat, twin-engine, stealth fighter technology demonstrator prototype designed for the United States Air Force (USAF). The design team, with Northrop as the prime contractor, was a finalist in the USAF's Advanced Tactical Fighter (ATF) demonstration/validation competition, battling the YF-22 team for full-scale development and production. Two YF-23 prototypes were built.

<span class="mw-page-title-main">Boeing X-32</span> Multirole combat aircraft prototype by Boeing

The Boeing X-32 is a concept demonstrator aircraft that was designed for the Joint Strike Fighter competition. It lost to the Lockheed Martin X-35 demonstrator, which was further developed into the Lockheed Martin F-35 Lightning II.

<span class="mw-page-title-main">Lockheed YF-22</span> Prototype demonstrator aircraft for the U.S. Air Force Advanced Tactical Fighter program

The Lockheed/Boeing/General Dynamics YF-22 is an American single-seat, twin-engine, stealth fighter technology demonstrator prototype designed for the United States Air Force (USAF). The design team, with Lockheed as the prime contractor, was a finalist in the USAF's Advanced Tactical Fighter (ATF) competition, and two prototypes were built for the demonstration/validation phase. The YF-22 team won the contest against the YF-23 team for full-scale development and the design was developed into the Lockheed Martin F-22. The YF-22 has a similar aerodynamic layout and configuration as the F-22, but with notable differences in the overall shaping such as the position and design of the cockpit, tail fins and wings, and in internal structural layout.

<span class="mw-page-title-main">Elevator (aeronautics)</span> Aircraft control surface used to control pitch

Elevators are flight control surfaces, usually at the rear of an aircraft, which control the aircraft's pitch, and therefore the angle of attack and the lift of the wing. The elevators are usually hinged to the tailplane or horizontal stabilizer. They may be the only pitch control surface present, and are sometimes located at the front of the aircraft or integrated into a rear "all-moving tailplane", also called a slab elevator or stabilator.

<span class="mw-page-title-main">Stabilator</span> Fully movable aircraft stabilizer

A stabilator is a fully movable aircraft horizontal stabilizer. It serves the usual functions of longitudinal stability, control and stick force requirements otherwise performed by the separate parts of a conventional horizontal stabilizer and elevator. Apart from reduced drag, particularly at high Mach numbers, it is a useful device for changing the aircraft balance within wide limits, and for reducing stick forces.

<span class="mw-page-title-main">Boeing Bird of Prey</span> Experimental aircraft in the US

The Boeing Bird of Prey is an American black project aircraft, intended to demonstrate stealth technology. It was developed by McDonnell Douglas and Boeing in the 1990s. The company provided $67 million of funding for the project; it was a low-cost program compared to many other programs of similar scale. It developed technology and materials which would later be used on Boeing's X-45 unmanned combat air vehicle. As an internal project, this aircraft was not given an X-plane designation. There are no public plans to make this a production aircraft. It is characterized as a technology demonstrator.

Lockheed <i>Have Blue</i> Experimental stealth aircraft

Lockheed Have Blue was the code name for Lockheed's proof of concept demonstrator for a stealth fighter. Have Blue was designed by Lockheed's Skunk Works division, and tested at Groom Lake, Nevada. The Have Blue was the first fixed-wing aircraft whose external shape was defined by radar engineering rather than by aerospace engineering. The aircraft's faceted shape was designed to deflect electromagnetic waves in directions other than that of the originating radar emitter, greatly reducing its radar cross-section.

<span class="mw-page-title-main">Empennage</span> Tail section of an aircraft containing stabilizers

The empennage, also known as the tail or tail assembly, is a structure at the rear of an aircraft that provides stability during flight, in a way similar to the feathers on an arrow. The term derives from the French language verb empenner which means "to feather an arrow". Most aircraft feature an empennage incorporating vertical and horizontal stabilising surfaces which stabilise the flight dynamics of yaw and pitch, as well as housing control surfaces.

<span class="mw-page-title-main">Vertical stabilizer</span> Aircraft component

A vertical stabilizer or tail fin is the static part of the vertical tail of an aircraft. The term is commonly applied to the assembly of both this fixed surface and one or more movable rudders hinged to it. Their role is to provide control, stability and trim in yaw. It is part of the aircraft empennage, specifically of its stabilizers.

<span class="mw-page-title-main">Twin tail</span> Type of vertical stabilizers on aircraft

A twin tail is a type of vertical stabilizer arrangement found on the empennage of some aircraft. Two vertical stabilizers—often smaller on their own than a single conventional tail would be—are mounted at the outside of the aircraft's horizontal stabilizer. This arrangement is also known as an H-tail, as it resembles a capital "H" when viewed from the rear. The twin tail was used on a wide variety of World War II multi-engine designs that saw mass production, especially on the American B-24 Liberator and B-25 Mitchell bombers, the British Avro Lancaster and Handley Page Halifax heavy bombers, and the Soviet Union's Petlyakov Pe-2 attack bomber.

<span class="mw-page-title-main">Stabilizer (aeronautics)</span> Aircraft component

An aircraft stabilizer is an aerodynamic surface, typically including one or more movable control surfaces, that provides longitudinal (pitch) and/or directional (yaw) stability and control. A stabilizer can feature a fixed or adjustable structure on which any movable control surfaces are hinged, or it can itself be a fully movable surface such as a stabilator. Depending on the context, "stabilizer" may sometimes describe only the front part of the overall surface.

<span class="mw-page-title-main">Joint Strike Fighter program</span> Joint aircraft development and acquisition program for the U.S. Air Force, Marine Corps, and Navy

Joint Strike Fighter (JSF) is a development and acquisition program intended to replace a wide range of existing fighter, strike, and ground attack aircraft for the United States, the United Kingdom, Italy, Canada, Australia, the Netherlands, Denmark, Norway, and formerly Turkey. After a competition between the Boeing X-32 and the Lockheed Martin X-35, the latter aircraft was selected for a contract award and developed into the F-35 Lightning II, which will replace various tactical aircraft, including the US F-16, A-10, F/A-18A-D, AV-8B, EA-6B and British Harrier GR7, GR9s and Tornado GR4. The projected average annual cost of the program is $12.5 billion in 2012 with an estimated cost in 2024 of $2 trillion over its lifespan.

<span class="mw-page-title-main">Tailless aircraft</span> Aircraft whose only horizontal aerodynamic surface is its main wing

In aeronautics, a tailless aircraft is a fixed-wing aircraft with no other horizontal aerodynamic surface besides its main wing. It may still have a fuselage, vertical tail fin, and/or vertical rudder.

<span class="mw-page-title-main">Rolls-Royce LiftSystem</span> Aircraft propulsion system

The Rolls-Royce LiftSystem, together with the F135 engine, is an aircraft propulsion system designed for use in the STOVL variant of the F-35 Lightning II. The complete system, known as the Integrated Lift Fan Propulsion System (ILFPS), was awarded the Collier Trophy in 2001.

Throughout a normal flight, a pilot controls an aircraft through the use of flight controls including maintaining straight and level flight, as well as turns, climbing, and descending. Some controls, such as a "yoke" or "stick" move and adjust the control surfaces which affects the aircraft's attitude in the three axes of pitch, roll, and yaw. Other controls include those for adjusting wing characteristics and those that control the power or thrust of the propulsion systems. The loss of primary control systems in any phase of flight is an emergency. Aircraft are not designed to be flown under such circumstances; however, some pilots faced with such an emergency have had limited success flying and landing aircraft with disabled controls.

References

  1. 1 2 3 4 Evan Hadingham (2003-01-01). "Winner Take All (All the nail biting, second guessing, and sheer engineering brilliance in the battle to build the better Joint Strike Fighter.)". Air & Space Magazine: 2&3. Retrieved 2008-05-05.
  2. 1 2 "Nova Transcript: Battle of the X-Planes". PBS. 2003-02-02. Retrieved 2008-05-21.
  3. "McDD/Northrop/BAe ASTOVL/MRF/JAST/JSF studies". Secret Projects Forum. Retrieved 2021-07-19.
  4. Paper on the 42nd AIAA Aerospace Sciences Meeting and Exhibit explaining the construction of a Pelikan tail model Archived 2006-10-14 at the Wayback Machine
  5. Virginia Tech on building An Unmanned Combat Air Vehicle for the Navy Archived 2013-03-17 at the Wayback Machine (explains technical details of the Pelikan tail)