Combat Aircraft Projects & Designs - Index in 2nd post

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PZL 230F Skorpion (POLAND)
After reviewing Soviet experiences in Afghanistan, the Polish air force desired a plane similar to the Soviet Su-25 Frogfoot and American A-10 Warthog. The Skorpion project started in 1988, and called for a heavily armoured, STOL-capable, fly-by-wire attack jet that was cheap enough to be offered for export as well.

The Skorpion overall was designed to present the smallest possible target to AA gunners. The initial design called for canards, however it was discovered that these were not needed and deleted from the mock-up. The armoured engine nacelles were placed aft near the fuselage (as in the A-10) making it difficult to target the plane with MANPADS. The engines exhausted well behind the end of the fuselage and wing trailing edges, minimizing damage if a SAM did hit. The nacelles were set at a slight down angle, partially obscuring the compressor blades from radar and giving a slight stealth quality. The landing gear was rugged and the plane needed only 1320 of runway to take off.

The armament was to be a 25mm gun, and 8824lbs of external ordnance.

The Polish air force was enthusiastic about the project and ignored Soviet concerns about one of its satellites producing a competitor to the Frogfoot. However, the overthrow of the communist regime in 1989 put the project on hiatus in 1990. In late 1992, the air force again reaffirmed its commitment to buying the plane; however by 1994 it was clear that Poland was on its way to NATO membership and the air force sought F-16 Falcons instead. The Skorpion was cancelled later that year.

 

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IAR 95 (ROMANIA)

The IAR 95 Spey was a Romanian project to produce a supersonic fighter jet for the Romanian Air Force. The project was started in the late 1970s and cancelled in 1981. Shortly after, the project was restarted again. The project was cancelled for good in 1988 due to lack of funds before a prototype could be built, although a full-scale mockup was being constructed.

The design was a high wing monoplane with lateral air intakes, a single fin, and a single engine. Designs with two fins and two engines were also considered but it was decided to go with the single engine single fin design. Other designations given to this project are IAR-101 and IAR-S and refer to different design layouts. The IAR-95 is similar in appearance and (projected) performance to the JF-17 Thunder, a joint Chinese-Pakistani fighter jet designed in the 1990s.

Romania considered a joint program with Yugoslavia, but the latter declined because it was designing its own supersonic fighter jet, the Novi Avion.

 

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ALR Piranha (SWITZERLAND)

In the early 1980s, Switzerland shortlisted two options for replacing its Hunter and Mirage aircraft: a small number of F/A-18 Hornets, or, abandoning jet fighters altogether and buying the MIM-104 Patriot SAM. The ALR company proposed a third route; a locally-built lightweight, extremely cheap fighter that could conceivably replace the Hunters and Mirages on a 1-for-1 basis; or (in smaller quantities) in addition to the Hornets or Patriots. Because it was intended solely for defense of small Switzerland, range was unimportant and the plane could be extremely small. The Piranha was a single-seat, single-engine delta design with canards. It was intended to be compatible with a number of off-the-shelf French, British, and American engines. Two versions were envisioned:

Piranha VI: A supersonic fighter with an afterburning turbojet (probably the General Electric F404), digital fly-by-wire controls, and radar.

Piranha I: An even more simple subsonic daylight interceptor and ground-support plane; with no radar, fixed inlets, a drag chute for landing, and up to 15,000lbs of small bombs. It was planned that this version could use small airstrips or even stretches of highway.

In addition to Switzerland, it was planned that as many as 2700 could be sold worldwide to third-world air forces. However, the Swiss eventually decided on the F/A-18 and the Piranha project died.

 

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EWR VJ-101 (WEST GERMANY)
This ambitious project was to be the successor to the F-104 Starfighter in Luftwaffe service. The designing firm, EWR, was a conglomeration between Heinkel and MBB formed in 1959 for the express purpose of building this airplane.

The VJ-101 had two tilting twin-engine pods on the wingtips plus another two engines in the fuselage for takeoff and landing lift. The four wing engines were equipped with afterburners and the VJ-101 would have been the first bisonic V/STOL plane ever. The sleek fuselage somewhat resembled the F-104 it would have replaced. The pressurized cockpit was equipped with a 0/0 ejection seat.

The first hovering flight was on 10 April 1963, and the first transition to level flight ten days later. On 14 September 1963, the second prototype achieved Mach 1.04 making it the first supersonic V/STOL plane ever.

Despite the apparent bright future of the project, it was cancelled in 1968 due to high cost and also doubts as to its meager planned weapons loadout. The second prototype is today displayed at the Deutsches Museum in Munich.

 

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VFW VAK 191B (WEST GERMANY)
The VFW VAK 191B was an experimental German VTOL strike fighter of the early 1970s. Designed and built by the Vereinigte Flugtechnische Werke (VFW) it was intended to lead to a replacement for the Fiat G.91.

The VAK 191B was produced by the German company Vereinigte Flugtechnische Werke (VFW). Initially, Fiat of Italy was also involved but dropped out in 1967, though it remained as a major sub-contractor.

Propulsion was provided by a Rolls-Royce/MAN Turbo RB.193-12 vectored thrust engine for both lift and cruise which was augmented by two vertical lift engines.

The program was begun in 1962 to replace the Fiat G.91 ground attack fighter with a VTOL aircraft but NATO requirements changed and it became a technology demonstrator. Three VAK 191B aircraft were flown in the flight test program between 1970-1975 making 91 flights. The first hovering flight was made in Bremen on 20 September 1971. The first transition from vertical flight to horizontal and vice versa was achieved on 26 October 1972 in Munich. The prototypes were used to test some of the concepts in what was to become the Panavia Tornado programme, including 'fly-by-wire' technology.

The VAK 191B was similar in concept to the British Harrier, but was designed for a supersonic dash capability (Mach 1.2-1.4) at medium to high altitudes. It was judged that having a single engine would create too much drag, but the two lift engines were dead weight in cruise, and the small cruise engine gave a poor thrust to weight ratio. It also had very small highly loaded wings. By contrast, the Harrier had a much higher thrust to weight ratio, it was effective as a dogfighter, and had larger wings which were put to good use in rolling short takeoffs.

 

[Manticore]

mako lca

mako trainer

 

[DANGER-ZONE]

GREAT JOB antibody....thumbz up

 

[Manticore]

thanks bro! -- this thread has really grown and i came to know of quite a few forgotten fighters myself in the process

 

[Manticore]

--kifr- extra ecm space below vertical stabilizer?

 

[Manticore]

Airplanes are transportation devices which are designed to move people and cargo from one place to another. Airplanes come in many different shapes and sizes depending on the mission of the aircraft. The airplane shown on this slide is a turbine-powered airliner which has been chosen as a representative aircraft.

For any airplane to fly, one must lift the weight of the airplane itself, the fuel, the passengers, and the cargo. The wings generate most of the lift to hold the plane in the air. To generate lift, the airplane must be pushed through the air. The air resists the motion in the form of aerodynamic drag. Modern airliners use winglets on the tips of the wings to reduce drag. The turbine engines, which are located beneath the wings, provide the thrust to overcome drag and push the airplane forward through the air. Smaller, low-speed airplanes use propellers for the propulsion system instead of turbine engines.

To control and maneuver the aircraft, smaller wings are located at the tail of the plane. The tail usually has a fixed horizontal piece, called the horizontal stabilizer, and a fixed vertical piece, called the vertical stabilizer. The stabilizers' job is to provide stability for the aircraft, to keep it flying straight. The vertical stabilizer keeps the nose of the plane from swinging from side to side, which is called yaw. The horizontal stabilizer prevents an up-and-down motion of the nose, which is called pitch. (On the Wright brother's first aircraft, the horizontal stabilizer was placed in front of the wings. Such a configuration is called a canard after the French word for "duck").

At the rear of the wings and stabilizers are small moving sections that are attached to the fixed sections by hinges. In the figure, these moving sections are colored brown. Changing the rear portion of a wing will change the amount of force that the wing produces. The ability to change forces gives us a means of controlling and maneuvering the airplane. The hinged part of the vertical stabilizer is called the rudder; it is used to deflect the tail to the left and right as viewed from the front of the fuselage. The hinged part of the horizontal stabilizer is called the elevator; it is used to deflect the tail up and down. The outboard hinged part of the wing is called the aileron; it is used to roll the wings from side to side. Most airliners can also be rolled from side to side by using the spoilers. Spoilers are small plates that are used to disrupt the flow over the wing and to change the amount of force by decreasing the lift when the spoiler is deployed.

The wings have additional hinged, rear sections near the body that are called flaps. Flaps are deployed downward on takeoff and landing to increase the amount of force produced by the wing. On some aircraft, the front part of the wing will also deflect. Slats are used at takeoff and landing to produce additional force. The spoilers are also used during landing to slow the plane down and to counteract the flaps when the aircraft is on the ground. The next time you fly on an airplane, notice how the wing shape changes during takeoff and landing.

The fuselage or body of the airplane, holds all the pieces together. The pilots sit in the cockpit at the front of the fuselage. Passengers and cargo are carried in the rear of the fuselage. Some aircraft carry fuel in the fuselage; others carry the fuel in the wings.
As mentioned above, the aircraft configuration in the figure was chosen only as an example. Individual aircraft may be configured quite differently from this airliner. The Wright Brothers 1903 Flyer had pusher propellers and the elevators at the front of the aircraft. Fighter aircraft often have the jet engines buried inside the fuselage instead of in pods hung beneath the wings. Many fighter aircraft also combine the horizontal stabilizer and elevator into a single stabilator surface. There are many possible aircraft configurations, but any configuration must provide for the four forces needed for flight.http://www.grc.nasa.gov/WWW/K-12/airplane/airplane.html

 

[Manticore]

the aerodynamics of the fighter also play an important role, other than the thrust to wt ratio..

Delta aircrafts have lower wingloading thus higher ITR.Swept winged have higher wingloading thus lower ITR.
Delta aircrafts are less aerodynamic so bleed more energy on turns, hence lower STR whereas swept winged planes have a higher STR since they bleed less energy.

The disadvantages, especially marked in the older tailless delta designs,[interceptors] are a loss of total available lift caused by turning up the wing trailing edge or the control surfaces (as required to achieve a sufficient stability) and the high induced drag of this low-aspect ratio type of wing. This causes delta-winged aircraft to 'bleed off' energy very rapidly in turns, a disadvantage in aerial maneuver combat and dogfighting.-- modern delta winged, also use canards aswell

http://dc201.*******.com/img/VAU1iZDQ/0.028808484240299914/Delta_wing_-_Wikipedia_the_fre.png

 

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http://dc192.*******.com/img/QzvuBwoG/85940main_FS-002-DFRC_popup5.jpg

 

[Manticore]

Aircraft Design: Fluid and Mechatronic Systems: IEI: LiU

Aircraft Design and Aircraft Systems

 

[Manticore]

The F-16 can use the the leading edge flap at different angle inflections including negative ones to reduce drag, in fact the F-16 has its leading edge flap at -2 deg to improve the airfoil`s supersonic lift/drag ratio

Wing lift can be increased by using these techniques:1.

Increasing the wing area.2.Increasing the wing camber.3.Delaying the flow separation.Various combinations of these techniques are employed to produce the high lift coefficients required for takeoff and landing tasks. Typical lift augmentation designs employ leading and trailing edge flaps and a variety of BLC schemes including slots, slats, suction and blowing, and the use of vortices.


The relative benefit of each particular technique depends upon the lift characteristics of the wing on which it's used. For example, a trailing edge flap on a propeller airplane with a straight wing might increase CL max three times as much as the same flap on a jet with a swept wing.

TRAILING EDGE FLAPS Trailing edge flaps are employed to change the effective wing camber. They normally affect the aft 15% to 20% of the chord. The most common types of trailing edge flaps are shown in figure 3.6.

FIXED WING PERFORMANCE3.12 Basic sectio Plain Split Slotted Fowler Figure 3.6
COMMON TRAILING EDGE FLAPSThe wing-flap combination behaves like a different wing, with characteristics dependent upon the design of the flap system. The plain flap is simply a hinged aft portion of the cross section of the wing, as used in the T-38. The split flap is a flat plate deflected from the lower surface of the wing, as in the TA-4. Slotted flaps direct high energy air over the upper flap surfaces to delay separation, as in the F-18 and U-21. Fowler flaps are slotted flaps which translate aft as they deflect to increase both the area of the wing and the camber, as in the T-2 and P-3. The relative effectiveness of the various types of trailingedge flaps is shown in figure 3.7.

STALL SPEED DETERMINATION 3.13 Basic section Plain Split Slotted Fowler Lift Coefficient CL Angle of Attack - degα Figure 3.7
LIFT CHARACTERISTICS OF TRAILING EDGE FLAPS
All types provide a significant increase in CL max, without altering the lift curve slope. An added benefit is the reduction in the α for CL max, which helps the field of view over the nose at high lift conditions and reduces the potential for geometric limitations due to excessive α during takeoff and landing.3.3.5.3 BOUNDARY LAYER CONTROL Lift enhancement can be achieved by delaying the airflow separation over the wing surface. The boundary layer can be manipulated by airfoils or other surfaces installed alongthe wing leading edge. In addition, suction or blowing techniques can be employed at various locations on the wing to control or energize the boundary layer. Vortices are also employed to energize the boundary layer and delay airflow separation until a higher α. Different types of BLC are discussed in the following sections.
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FIXED WING PERFORMANCE3.143.3.5.3.1

LEADING EDGE DEVICES

Leading edge devices are designed primarily to delay the flow separation until a higher α is reached. Some common leading edge devices are shown in figure 3.8. Drooped leading edge Movable slat Krüger flap Figure 3.8 SAMPLE LEADING EDGE DEVICES The lift provided from the leading edge surface is negligible; however, by helping the flow stay attached to the wing, flight at higher α is possible. An increase in CL max is realized, corresponding to the lift resulting from the additional α available as shown infigure 3.9.



STALL SPEED DETERMINATION 3.15 Basic section Droop, slat, or Krüger flap Angle of Attack - deg α Lift Coefficient CL Figure 3.9 LEADING EDGE DEVICE EFFECTS Since the α for CL max may be excessively high, leading edge devices and slots are invariably used in conjunction with trailing edge flaps (except in delta wings) in order to reduce the α to values acceptable for take off and landing tasks

.3.3.5.3.2 BLOWING AND SUCTION BLC can also involve various blowing or suction techniques. The concept is to prevent the stagnation of the boundary layer by either sucking it from the upper surface or energizing it, usually with engine bleed air. If BLC is employed on the leading edge, the effect is similar to a leading edge device. The energized flow keeps the boundary layer attached, allowing flight at higher α. If the high energy air is directed over the main part ofthe wing or a trailing edge flap (a blown wing or flap), the effect is similar to adding a trailing edge device. In either application if engine bleed air is used, the increase in lift is proportional to thrust .3.3.5.3.3 VORTEX LIFT Vortices can be used to keep the flow attached at extremely high α. Strakes in the F-16 and leading edge extensions in the F-18 are used to generate powerful vortices at high α. These vortices maintain high energy flow over the wing and make dramatic lift

FIXED WING PERFORMANCE 3.16 improvements.
Canard surfaces can be used to produce powerful vortices for lift as well as pitching moments for control, as in the Gripen, Rafale, European fighter aircraft, and X-31 designs.3.3.6 FACTORS AFFECTING CL MAX3.3.6.1 LIFT FORCES To specify the airplane’s maximum lift coefficient, it is necessary to examine the forces which contribute to lift. Consider the airplane in a glide as depicted in figure 3.10.Horizon Relative wind WαjD LaeroγTG ατTG sin αj Figure 3.10 AIRPLANE IN STEADY GLIDE Where: α Angle of attack deg α jThrust angle deg D Drag l bγFlight path angle deg Laero Aerodynamic lift lb τInclination of the thrust axis with respect to the chord line deg TGGross thrustlbWWeightlb. http://www.aviation.org.uk/docs/flighttest.navair.navy.milunrestricted-FTM108/c3.pdf

 

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In the airplane’s normal range of flight attitudes, if the angle of attack is increased, the center of pressure moves forward; and if decreased, it moves rearward. Since the center of gravity is fixed at one point, it is evident that as the angle of attack increases, the center of lift (CL) moves ahead of the center of gravity, creating a force which tends to raise the nose of the airplane or tends to increase the angle of attack still more. On the other hand, if the angle of attack is decreased, the center of lift (CL) moves aft and tends to decrease the angle a greater amount. It is seen then, that the ordinary airfoil is inherently unstable, and that an auxiliary device, such as the horizontal tail surface, must be added to make the airplane balance longitudinally.

The balance of an airplane in flight depends, therefore, on the relative position of the center of gravity (CG) and the center of pressure (CP) of the airfoil. Experience has shown that an airplane with the centerof gravity in the vicinity of 20 percent of the wing chord can be made to balance and fly satisfactorily.
That is the reason the F-16XL and LCA have leading edge notches to reduce pitch up momentum and probably the LEVCON also dampens the pitch up momentum

Pilot's Handbook of Aeronautical Knowledge Chapter 2 - American Flyers