|
F-104 Starfighter
The Lockheed F-104 Starfighter was the last of the day fighters, a high-performance supersonic interceptor aircraft capable of high speeds and climb rates. In this role the Starfighter served for only a short time and was generally
disliked by the US Air Force which found its range, load-carrying ability, and equipment inadequate for the service's needs. The Starfighter gained a second lease on life in the 1960s, when it was selected as the basis for a high-speed
fighter-bomber by a European commission. Many served in this role into the 1980s. In some countries the Starfighter gained the reputation of being an extremely unsafe aircraft.
History
In 1951, "Kelly" Johnson, chief engineer at Lockheed's Skunk Works, visited Korea and talked to fighter pilots about what sort of plane they wanted. At the time the US pilots were meeting the MiG-15 in their F-86s and many of the American pilots
felt that the MiGs were superior to the larger and more complex American design. The pilots requested a small and simple aircraft with excellent performance.
On his return to the US, Johnson immediately started the design of just such an aircraft. In March his team was assembled and they studied several aircraft designs ranging from small designs at 8,000 lb (3.6 t), to fairly large ones at 50,000 lb
(23 t). In November, 1952, a follow-on study started, the lessons learned from the earlier designs being used to eventually result in the Lockheed L-246, of about 12,000 lb (5.4 t). The 246 remained essentially identical to the Starfighter as
eventually delivered.
The design was presented to the Air Force in November, 1952, and they were interested enough to create a new proposal and to invite several companies to participate. Three additional designs were received: the Republic AP-55, an improved version of
its prototype XF-91 Thunderceptor, the North American NA-212 which would eventually evolve into the F-107, and the Northrop N-102 Fang, a new General Electric J-79-powered design. Although all were interesting, Lockheed had an insurmountable lead
and was granted a development contract in March, 1953.
Work progressed quickly with a mock-up ready for inspection at the end of April, and work starting on two prototypes late in May. At the time, the J-79 engine was not ready so both prototypes were designed to use the Wright J-65 engine instead, a
licensed version of the Armstrong Siddeley Sapphire. The first prototype was completed by early 1954, and started flying in March. The total time from design to flying was about two years, unheard of even then, let alone today when ten to fifteen
years is more typical.
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 wing design was radical. Most jet fighters of the period (and to this day) used a swept-wing or delta-wing
platform. 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. The wings contained no fuel, necessitating the tanks and landing gear be contained in the fuselage.
The stabalizator (horizontal tail surface) was mounted atop the fin to reduce inertial 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 manoeuvring, 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 but extremely unforgiving of pilot error.
The small, highly-loaded wing resulted in an unacceptably high takeoff 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.
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 the deletion of 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
aluminium 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 updated marks of the J79, improving thrust by almost 20%.
Equipment and armament
Early Starfighter's used a downward-firing ejection seat (the Lockheed C-1), out of concern over the ability of an upward-firing seat to clear the
tail plane. This presented obvious problems in low-altitude escapes, and some 21 USAF pilots failed to
escape their stricken aircraft in low-level emergencies because of it. The downward-firing seat was soon replaced by a Lockheed C-2 upward-firing seat which was capable of clearing the tail, although it still had a minimum speed limitation of 90
knots (170 km/h). Most export Starfighter's were fitted with Martin-Baker ejection seats with zero/zero (zero altitude, zero airspeed) capability which, no doubt, was comforting to pilots.
The initial USAF Starfighter's had basic AN/ASG-14T ranging radar, TACAN, and radio. The later international fighter-bomber aircraft had much more advanced
Aeronautics NASARR radar, a simple infrared sight, Litton LN-3 inertial navigation system,
and an air data computer. In the late 1960s, the Italian Air Force developed a more advanced version of the Starfighter, the F-104S, for use as an all-weather interceptor. The F-104S received a NASAAR R21-G with moving-target indicator (for some
ability against low-level targets) and a continuous-wave illuminator for semi-active radar homing missiles, including AIM-7 Sparrow and Selenia Aspide. The missile-guidance avionics forced the deletion of the Starfighter's internal cannon. In the
mid-1980s surviving F-104S aircraft were updated to ASA (Aggiornamento Sistema d'Arma, or Updated Weapons System) standard with a much improved, more compact Fiat R21G/M1 radar that also provided enough space to restore the gun.
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, is fed by a 725-round drum behind the pilot's seat. It was deleted in two-seat models and some single-seaters (the gun bay and ammunition tank could be replaced by an additional fuel tank). Two AIM-9 Sidewinder air-to-air missiles can be
carried on the wingtip stations which can alternately be used for fuel tanks or other stores. F-104C and later models added a
centreline pylon and two underwing pylons under each wing for bombs, nuclear weapons, rocket pods, or tanks. The
centreline 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
centreline available for other stores). The Italian F-104S also added an
additional pylon under each wing, for a maximum of nine. The F-104S was cleared for a higher maximum takeoff 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).
Pilot impressions
The Starfighter is generally considered a rewarding, if very demanding, "sports car" of a fighter. It was the first combat aircraft capable of sustained Mach 2 flight (not just a brief dash), and its speed and climb performance remain impressive by
modern standards. If used appropriately, with high-speed slashing attacks and good use of its exceptional thrust-to-weight ratio, it can be a formidable opponent, although being lured into a turning contest with a slower, more
manoeuvrable opponent
(as Pakistani pilots were with Indian Hunters in 1965) is perilous. The F-104's turn radius and high-alpha
behaviour have always been tricky, however, and the Starfighter has a well-deserved reputation for unforgiving
behaviour. Some users lost
nearly half their aircraft through accidents, although the accident rate varied widely depending on the user and operating conditions; the Spanish Air Force, for example, lost none. The Starfighter has been a particular
favourite of the Italian Air
Force, although the AMI's accident rate was far from the lowest of Starfighter users.
Service
The initial F-104A served briefly with the USAF Air Defence Command as an interceptor, although neither its range or armament were well-suited for that role. Its status was nonetheless enhanced when, on May 18, 1958, an F-104A set a world speed
record of 1,404.19 mph (2,260 km/h), and on December 14, 1959, an F-104C set a world altitude record of 103,395 ft (31.5 km). The Starfighter was the first aircraft to hold simultaneous official world records for speed, altitude, and time-to-climb.
The subsequent F-104C entered service with Tactical Air Command as a multi-role fighter and fighter-bomber. It saw service in the Vietnam War both in the air-superiority role (although it saw little aerial combat and scored no air-to-air kills) and
in the air support mission.
The USAF procured only 296 Starfighter's in one and two seat versions. The USAF was less than satisfied with the Starfighter. At the time USAF doctrine placed little importance on air superiority (the "pure" fighter mission), and the Starfighter was
deemed inadequate for either the interceptor or tactical fighter-bomber role, lacking both payload and endurance compared to other USAF aircraft. Its U.S. service quickly wound down after 1965.
Nevertheless, the F-104 found a new market with other NATO countries and 2,578 F-104s were built in the U.S. and abroad under the military aid program for various nations including Canada, West Germany, Italy, Norway, the Netherlands, Belgium,
Denmark, Greece, Turkey, Spain, Pakistan, the Republic of China (Taiwan), and Japan.
The so-called "Deal of the Century" produced considerable income for Lockheed, but considerable political controversy in Europe, particularly in Germany, where minister of defence Franz Josef Strauss was almost forced to resign over the issue.
Prince Bernhard of the Netherlands was also connected to being bribed by Lockheed, and he later confessed having received more than 1 mill. USD. Many considered the Starfighter program a politically motivated enterprise, with governments browbeaten
into accepting a USAF cast-off out of U.S. political pressure. This debate was exacerbated by the F-104's alarming accident rate (in German service alone 292 of the 916
Starfighter's crashed, claiming the lives of 115 pilots), leading to cries that
the Starfighter was fundamentally unsafe. In the 1970s it was revealed that Lockheed had engaged in an extensive campaign of bribery of foreign officials to obtain sales, a scandal that nearly led to the ailing corporation's downfall. Although that
scandal was not specifically connected with the Starfighter, some have speculated that Lockheed's aggressive, sometimes bribery-based sales tactics stretched back to the "Deal of the Century" as well.
The F-104 in international service began to wind down in the late 1970s, replaced in many cases by the F-16, but it remained in service with some air forces for another two decades. The last frontline
Starfighter's were with the Italian AMI, which
retired in summer 2004.
|
|
