Sunday, October 01, 2006
F-104 Starfighter
The Lockheed F-104 Starfighter is a high-performance supersonic interceptor aircraft, capable of high speeds and climb rates. The Starfighter entered service with the US Air Force in 1958 and was phased out by 1967 by the USAF and in the 70s by the ANG. However, an updated Starfighter sold well abroad, particularly in NATO among the air forces of Germany, Canada, and Italy, where high-speed fighter-bomber versions usually continued in service until the mid 1980s (and, in the case of the Italian Air Force, until 2004). The later model Starfighter versions also gained an unenviable reputation for being challenging to fly. Germany made further modifications to their aircraft, which proved fatal-they suffered much higher fatal accident rates, where it gained nicknames like "widowmaker" and "earth nail" for frequently driving itself into the ground. Many air forces that used F-104s eventually replaced them with the F-16 Fighting Falcon.
Design
In order to achieve the desired performance, Lockheed chose a minimalist approach: a design that would achieve high performance by wrapping the lightest, most aerodynamically efficient airframe possible around a single powerful engine. The emphasis was on minimizing drag and mass.
Wing and fuselage
The F-104 had a radical wing design. Most jet fighters of the period (and to this day) used a swept-wing or delta-wing planform. This allowed a reasonable balance between aerodynamic performance, lift, and internal space for fuel and equipment. Lockheed's tests, however, determined that the most efficient shape for high-speed, supersonic flight was a very small, straight, mid-mounted, trapezoidal wing. The wing was extremely thin, with a thickness-to-chord ratio of only 3.36%. Its aspect ratio was 2.45. The wing's leading edges were so thin (0.016 in / 0.41 mm) and so sharp that they presented a hazard to ground crews, and protective guards had to be installed during ground operations. The thinness of the wings meant that fuel tanks and landing gear had to be contained in the fuselage. Equally the motors to drive to the control surfaces had to be only one inch (25 mm) thick to fit.
The stabilator (horizontal tail surface) was mounted atop the fin to reduce inertia coupling. Because the vertical tailfin was only slightly shorter than the length of each wing and nearly as aerodynamically effective, it could act as a wing on rudder application (a phenomenon known as Dutch roll). To offset this effect, the wings were canted downward, given 10° anhedral. The wings had both leading- and trailing-edge flaps. Later Starfighter marks incorporated a system that allowed the flaps to be extended during combat maneuvering, reducing turn radius and generally improving sustained turn rate.
The combination provided extremely low drag except at high angle of attack (alpha), at which point induced drag became very high. As a result the Starfighter had superb acceleration, rate of climb, and potential top speed, but its sustained turn performance was very poor, described by some as more like a milk truck than a fighter. It was sensitive to control input, and extremely unforgiving of pilot error.
The small, highly-loaded wing resulted in an unacceptably high take-off and landing speed, so a boundary layer control system (BLCS) of blown flaps was incorporated, bleeding engine air over the trailing edge flaps to improve their lift. The system was a boon to safe landings, although it proved to be a maintenance problem in service, and landing without the BLCS could be harrowing.
NACA wind tunnel tested a model of the F-104, to evaluate its stability, and found it became increasingly unstable at higher angles of attack, to the point that it was recommended to limit the servo-control power to generate those higher angles and shake the stick to warn the pilot. In the same report, NACA stated that the wingtip tanks, possibly because of their stabilizing fins, reduced somewhat the model's instability problems at high angles of attack.
A research version called Lancer, fitted with a bigger, higher aspect ratio wing and a rocket engine, was employed to develop rocket controls for yaw, pitch and roll, to be used at extremely high altitudes, where conventional aerodynamic control surfaces lost much of their effectiveness. The few pilots to have flown the Lancer used to say that, due to its bigger wing, it was extremely nimble and a better dogfighter than any other plane. Later, those same rocket controls where installed on the X-15 rocket plane for use in its record-breaking high-altitude flights.
The Starfighter's fuselage had a high fineness ratio, i.e., tapering sharply towards the nose, and small frontal area. The fuselage was tightly packed, containing the radar, cockpit, cannon, all fuel, landing gear, and engine.
Several two-seat training versions of the Starfighter were produced. They were generally similar to the comparable single-seater, but the additional cockpit required removing the cannon and some internal fuel. Two-seaters are combat-capable, and, despite a slightly larger vertical fin and increased weight, have similar performance to the single-seater.
Engine
The F-104 was built around the General Electric J79 turbojet engine, fed by side-mounted intakes with fixed inlet scoops and a conical ramp optimized for supersonic speeds. (Unlike some supersonic aircraft, the F-104 does not have variable-geometry inlets.) Its thrust-to-drag ratio was superb, allowing a maximum speed well in excess of Mach 2: the top speed of the Starfighter is limited more by the aluminum structure and the temperature limits of the engine than by thrust or drag (which gives an aerodynamic maximum speed of Mach 2.2). Later models used uprated marks of the J79, improving thrust by almost 30%.
Basic armament of the F-104 was the M61 Vulcan 20 mm Gatling gun. The Starfighter was the first aircraft to carry the new weapon, which had a phenomenal rate of fire of 6,000 rounds per minute. The cannon, mounted in the lower part of the port fuselage, was fed by a 725-round drum behind the pilot's seat. It was deleted in two-seat models and some single-seat models, including reconnaissance versions and the early Italian F-104S models (the gun bay and ammunition tank could be replaced by an additional fuel tank). Two AIM-9 Sidewinder air-to-air missiles could be carried on the wingtip stations, which could also be used for fuel tanks or other stores. F-104C and later models added a centerline pylon and two underwing pylons under each wing for bombs, nuclear weapons, rocket pods, or tanks. The centerline pylon could carry a "catamaran" launcher for two additional Sidewinders, although the installation had minimal ground clearance and made the seeker heads of the missiles vulnerable to ground debris. The F-104S and some F-104G and F-104J models added a pair of fuselage pylons beneath the intakes, usually used for Sidewinders (providing better ground clearance than the catamaran launcher and leaving the centerline available for other stores). The Italian F-104S had still another pylon under each wing, for a maximum of nine. The F-104S was cleared for a higher maximum take-off weight, allowing it to carry up to 7,500 lb (3,400 kg) of stores; other Starfighters had a maximum external load of 4,000 lb (1,814 kg).
Service with Pakistan Air Force
Pakistan was the first country in Asia to get a supersonic aircraft when they acquired the F-104 Starfighter in 1961.
The Starfighter got its first kill on the dawn of 6 September 1965 when Flight Lieutenant Aftab Alam Khan in an F-104 destroyed a Dassault Mystère IV over West Pakistan skies and damaged another, to mark the start of aerial combat in the Indo-Pakistani War of 1965. The engagement was significant in many respects. It marked a new era in dogfighting at very low altitude. It was the first combat kill by any Mach 2 aircraft, and the first missile kill for the Pakistan Air Force. Though the F-86 was the mainstay of the PAF, the F-104 had a very special task.
The Starfighter is also believed to have been instrumental in intercepting an Indian Air Force (IAF) Folland Gnat earlier on 3 September 1965. The Gnat was flying over Pakistan, on its way to its home base, when a F-104 was vectored to intercept the aircraft. Closing in at supersonic speed, the F-104 crossed the Gnat. There was no chance of making a successful intercept. But the Gnat pilot, probably thinking that there were more aircraft in the area, promptly lowered his undercarriage, landed at a disused Pakistani airfield nearby and surrendered himself. The Gnat is now displayed at the PAF Museum, Karachi. Indians claim that contrary to this version of events that there was a navigation error that led to its pilot wrongly landing on a Pakistani airstrip. The IAF pilot, Sqn Ldr Brij Pal Singh (who later rose to be an Air Marshal in the IAF), was taken as a POW and later released. [1]
In the later Indo-Pakistani War of 1971, the F-104s were outfought and outgunned by the IAF's fighters and though Jordanian Starfighters were added to bolster the numbers, it did little to sway the air war in Pakistan's favour. It became the victim of the first supersonic dogfight in the subcontinent when an IAF MiG-21 shot down the starfighter. Up to 8 PAF Starfighters were shot down by IAF MiG-21s and even Pakistan admitted they didn't do so well, with up to seven losses and relatively few kills.
After the war the 12 PAF F-104s were grounded due to lack of spares resulting from the U.S. military embargo. They were replaced by French-made Dassault Mirage III fighters.
Land speed record car
A modified F-104A Starfighter airframe is being used for the North American Eagle land speed record jet car. The Eagle teams hopes to attain 800 mph (1,288 km/h) or Mach 1.05.
[edit]
Specifications (F-104G)
Data from Quest for Performance[5]
General characteristics
Crew: 1
Length: 54 ft 8 in (16.66 m)
Wingspan: 21 ft 9 in (6.36 m)
Height: 13 ft 6 in (4.09 m)
Wing area: 196.1 ft² (18.22 m²)
Airfoil: Biconvex 3.36% root and tip
Empty weight: 14,000 lb (6,350 kg)
Loaded weight: 20,640 lb (9,365 kg)
Max takeoff weight: 29,027 lb (13,170 kg)
Powerplant: 1× General Electric J79-GE-11A afterburning turbojet
Dry thrust: 10,000 lbf (48 kN)
Thrust with afterburner: 15,600 lbf (69 kN)
Zero-lift drag coefficient: 0.0172
Drag area: 3.37 ft² (0.31 m²)
Aspect ratio: 2.45
Performance
Maximum speed: 1,328 mph (2,125 km/h)
Range:
Combat: 420 mi (670 km)
Ferry: 1,630 mi (2,600 km)
Service ceiling: 50,000 ft (15,240 m)
Rate of climb: 48,000 ft/min (244 m/s)
Wing loading: 105 lb/ft² (514 kg/m²)
Thrust/weight: 0.76
Lift-to-drag ratio: 9.2
Armament
1x 20 mm M61 Vulcan with 725 rounds
4x AIM-9 Sidewinder
Up to 4,000 lb (1,815 kg) of bombs, rockets, or other stores on seven hardpoints
Design
In order to achieve the desired performance, Lockheed chose a minimalist approach: a design that would achieve high performance by wrapping the lightest, most aerodynamically efficient airframe possible around a single powerful engine. The emphasis was on minimizing drag and mass.
Wing and fuselage
The F-104 had a radical wing design. Most jet fighters of the period (and to this day) used a swept-wing or delta-wing planform. This allowed a reasonable balance between aerodynamic performance, lift, and internal space for fuel and equipment. Lockheed's tests, however, determined that the most efficient shape for high-speed, supersonic flight was a very small, straight, mid-mounted, trapezoidal wing. The wing was extremely thin, with a thickness-to-chord ratio of only 3.36%. Its aspect ratio was 2.45. The wing's leading edges were so thin (0.016 in / 0.41 mm) and so sharp that they presented a hazard to ground crews, and protective guards had to be installed during ground operations. The thinness of the wings meant that fuel tanks and landing gear had to be contained in the fuselage. Equally the motors to drive to the control surfaces had to be only one inch (25 mm) thick to fit.
The stabilator (horizontal tail surface) was mounted atop the fin to reduce inertia coupling. Because the vertical tailfin was only slightly shorter than the length of each wing and nearly as aerodynamically effective, it could act as a wing on rudder application (a phenomenon known as Dutch roll). To offset this effect, the wings were canted downward, given 10° anhedral. The wings had both leading- and trailing-edge flaps. Later Starfighter marks incorporated a system that allowed the flaps to be extended during combat maneuvering, reducing turn radius and generally improving sustained turn rate.
The combination provided extremely low drag except at high angle of attack (alpha), at which point induced drag became very high. As a result the Starfighter had superb acceleration, rate of climb, and potential top speed, but its sustained turn performance was very poor, described by some as more like a milk truck than a fighter. It was sensitive to control input, and extremely unforgiving of pilot error.
The small, highly-loaded wing resulted in an unacceptably high take-off and landing speed, so a boundary layer control system (BLCS) of blown flaps was incorporated, bleeding engine air over the trailing edge flaps to improve their lift. The system was a boon to safe landings, although it proved to be a maintenance problem in service, and landing without the BLCS could be harrowing.
NACA wind tunnel tested a model of the F-104, to evaluate its stability, and found it became increasingly unstable at higher angles of attack, to the point that it was recommended to limit the servo-control power to generate those higher angles and shake the stick to warn the pilot. In the same report, NACA stated that the wingtip tanks, possibly because of their stabilizing fins, reduced somewhat the model's instability problems at high angles of attack.
A research version called Lancer, fitted with a bigger, higher aspect ratio wing and a rocket engine, was employed to develop rocket controls for yaw, pitch and roll, to be used at extremely high altitudes, where conventional aerodynamic control surfaces lost much of their effectiveness. The few pilots to have flown the Lancer used to say that, due to its bigger wing, it was extremely nimble and a better dogfighter than any other plane. Later, those same rocket controls where installed on the X-15 rocket plane for use in its record-breaking high-altitude flights.
The Starfighter's fuselage had a high fineness ratio, i.e., tapering sharply towards the nose, and small frontal area. The fuselage was tightly packed, containing the radar, cockpit, cannon, all fuel, landing gear, and engine.
Several two-seat training versions of the Starfighter were produced. They were generally similar to the comparable single-seater, but the additional cockpit required removing the cannon and some internal fuel. Two-seaters are combat-capable, and, despite a slightly larger vertical fin and increased weight, have similar performance to the single-seater.
Engine
The F-104 was built around the General Electric J79 turbojet engine, fed by side-mounted intakes with fixed inlet scoops and a conical ramp optimized for supersonic speeds. (Unlike some supersonic aircraft, the F-104 does not have variable-geometry inlets.) Its thrust-to-drag ratio was superb, allowing a maximum speed well in excess of Mach 2: the top speed of the Starfighter is limited more by the aluminum structure and the temperature limits of the engine than by thrust or drag (which gives an aerodynamic maximum speed of Mach 2.2). Later models used uprated marks of the J79, improving thrust by almost 30%.
Basic armament of the F-104 was the M61 Vulcan 20 mm Gatling gun. The Starfighter was the first aircraft to carry the new weapon, which had a phenomenal rate of fire of 6,000 rounds per minute. The cannon, mounted in the lower part of the port fuselage, was fed by a 725-round drum behind the pilot's seat. It was deleted in two-seat models and some single-seat models, including reconnaissance versions and the early Italian F-104S models (the gun bay and ammunition tank could be replaced by an additional fuel tank). Two AIM-9 Sidewinder air-to-air missiles could be carried on the wingtip stations, which could also be used for fuel tanks or other stores. F-104C and later models added a centerline pylon and two underwing pylons under each wing for bombs, nuclear weapons, rocket pods, or tanks. The centerline pylon could carry a "catamaran" launcher for two additional Sidewinders, although the installation had minimal ground clearance and made the seeker heads of the missiles vulnerable to ground debris. The F-104S and some F-104G and F-104J models added a pair of fuselage pylons beneath the intakes, usually used for Sidewinders (providing better ground clearance than the catamaran launcher and leaving the centerline available for other stores). The Italian F-104S had still another pylon under each wing, for a maximum of nine. The F-104S was cleared for a higher maximum take-off weight, allowing it to carry up to 7,500 lb (3,400 kg) of stores; other Starfighters had a maximum external load of 4,000 lb (1,814 kg).
Service with Pakistan Air Force
Pakistan was the first country in Asia to get a supersonic aircraft when they acquired the F-104 Starfighter in 1961.
The Starfighter got its first kill on the dawn of 6 September 1965 when Flight Lieutenant Aftab Alam Khan in an F-104 destroyed a Dassault Mystère IV over West Pakistan skies and damaged another, to mark the start of aerial combat in the Indo-Pakistani War of 1965. The engagement was significant in many respects. It marked a new era in dogfighting at very low altitude. It was the first combat kill by any Mach 2 aircraft, and the first missile kill for the Pakistan Air Force. Though the F-86 was the mainstay of the PAF, the F-104 had a very special task.
The Starfighter is also believed to have been instrumental in intercepting an Indian Air Force (IAF) Folland Gnat earlier on 3 September 1965. The Gnat was flying over Pakistan, on its way to its home base, when a F-104 was vectored to intercept the aircraft. Closing in at supersonic speed, the F-104 crossed the Gnat. There was no chance of making a successful intercept. But the Gnat pilot, probably thinking that there were more aircraft in the area, promptly lowered his undercarriage, landed at a disused Pakistani airfield nearby and surrendered himself. The Gnat is now displayed at the PAF Museum, Karachi. Indians claim that contrary to this version of events that there was a navigation error that led to its pilot wrongly landing on a Pakistani airstrip. The IAF pilot, Sqn Ldr Brij Pal Singh (who later rose to be an Air Marshal in the IAF), was taken as a POW and later released. [1]
In the later Indo-Pakistani War of 1971, the F-104s were outfought and outgunned by the IAF's fighters and though Jordanian Starfighters were added to bolster the numbers, it did little to sway the air war in Pakistan's favour. It became the victim of the first supersonic dogfight in the subcontinent when an IAF MiG-21 shot down the starfighter. Up to 8 PAF Starfighters were shot down by IAF MiG-21s and even Pakistan admitted they didn't do so well, with up to seven losses and relatively few kills.
After the war the 12 PAF F-104s were grounded due to lack of spares resulting from the U.S. military embargo. They were replaced by French-made Dassault Mirage III fighters.
Land speed record car
A modified F-104A Starfighter airframe is being used for the North American Eagle land speed record jet car. The Eagle teams hopes to attain 800 mph (1,288 km/h) or Mach 1.05.
[edit]
Specifications (F-104G)
Data from Quest for Performance[5]
General characteristics
Crew: 1
Length: 54 ft 8 in (16.66 m)
Wingspan: 21 ft 9 in (6.36 m)
Height: 13 ft 6 in (4.09 m)
Wing area: 196.1 ft² (18.22 m²)
Airfoil: Biconvex 3.36% root and tip
Empty weight: 14,000 lb (6,350 kg)
Loaded weight: 20,640 lb (9,365 kg)
Max takeoff weight: 29,027 lb (13,170 kg)
Powerplant: 1× General Electric J79-GE-11A afterburning turbojet
Dry thrust: 10,000 lbf (48 kN)
Thrust with afterburner: 15,600 lbf (69 kN)
Zero-lift drag coefficient: 0.0172
Drag area: 3.37 ft² (0.31 m²)
Aspect ratio: 2.45
Performance
Maximum speed: 1,328 mph (2,125 km/h)
Range:
Combat: 420 mi (670 km)
Ferry: 1,630 mi (2,600 km)
Service ceiling: 50,000 ft (15,240 m)
Rate of climb: 48,000 ft/min (244 m/s)
Wing loading: 105 lb/ft² (514 kg/m²)
Thrust/weight: 0.76
Lift-to-drag ratio: 9.2
Armament
1x 20 mm M61 Vulcan with 725 rounds
4x AIM-9 Sidewinder
Up to 4,000 lb (1,815 kg) of bombs, rockets, or other stores on seven hardpoints
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U've launched ur blog too early, but info is good. Try to add more to it as quickly as possible
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