The Technical Evolution, Global Inventories and Logistical Anatomy of the F-104 Starfighter (Part 1)

Emerging during the escalation phase of the Cold War as a product of nuclear deterrence and high-altitude interception doctrines, the F-104 Starfighter represents a paradigm shift in military aviation. Developed by Lockheed, this platform not only redefined aerodynamic limits but also established one of the Cold War’s largest logistical and supply networks through licensed production models, consortium partnerships and intensive second-hand transfer traffic between allied nations. The efforts of countries in strategic theatres, such as Turkey and Taiwan, to maintain operational fleets comprising heterogeneous aircraft sourced from various origins have also made the aircraft’s logistical management history a unique case study. Our series aims to provide an in-depth perspective on the F-104 Starfighter.

PART 1: Historical Need and Design Philosophy

In the early years of the Cold War, the military aviation sector, driven by the high power potential offered by jet engines, steered aircraft design towards heavier, more complex and multi-role platforms. However, the aerial engagements during the Korean War (1950–1953) revealed that this design trend was at odds with operational realities. Pilots of the United States Air Force (USAF), flying the relatively heavy and complex North American F-86 Sabre, found themselves at a disadvantage against the Soviet-built Mikoyan-Gurevich MiG-15, which possessed superior climb rate, high-altitude performance and vertical manoeuvrability. In light of these developments, Lockheed’s legendary chief designer, Clarence L. “Kelly” Johnson, personally visited the American forward air bases in South Korea in November 1951 to conduct interviews with combat pilots. The pilots’ unanimous request was for the development of a simple fighter aircraft, free from complex systems, that was lightweight and combined climb rate and maximum altitude capability with speed. Upon his return to the US, Johnson established a dedicated design team within Skunk Works in March 1952. The team meticulously examined over 100 aircraft configurations, with weights ranging from 8,000 lb to 50,000 lb. As a result of this work, the L-246 (Lockheed Model 083) concept was selected, aiming to create the lightest and most aerodynamic fuselage possible built around the newly developed General Electric J79 turbojet engine. This minimalist approach formed the conceptual basis for the F-104 Starfighter, which would go down in aviation literature as the ‘manned missile’. The prototype development process was conducted under strict secrecy, and the first prototype, the XF-104, officially made its maiden flight on 4 March 1954 at Edwards Air Force Base, piloted by test pilot Tony LeVier. However, prior to this flight, a brief hop was recorded during high-speed taxi tests on 28 February 1954, during which the aircraft lifted off the ground by approximately 1.5 metres; this was not recognised as the official first flight. The first official flight was cut short of the planned duration, lasting just 21 minutes, as the landing gear could not be retracted due to insufficient hydraulic pressure. The secrecy surrounding the project was so strictly maintained that the first photographs of the aircraft were not released to the public until 1956, two years after its maiden flight. On 15 April 1955, the second XF-104 prototype was lost when excessive vibration during high-altitude gun-firing tests caused the cockpit ejection hatch to become dislodged. As cabin pressure dropped suddenly, pilot Herman ‘Fish’ Salmon’s pressure suit inflated excessively, completely obstructing his vision; believing he had lost control of the aircraft, Salmon was forced to eject as his seat shot downwards.

Chapter 2: Aerodynamic Design Philosophy

The F-104 Starfighter features a radical design that pushes the boundaries of conventional aeronautical principles, with the aim of exceeding the Mach 2 speed limit and sustaining this high speed. To minimise air resistance (drag) during supersonic flight, the aircraft’s fuselage cross-sectional area was kept as narrow as possible, with a sharp taper applied from the nose towards the tail.

Legendary aircraft designer Kelly Johnson took a different approach to the traditional swept-back or delta-wing configurations of the era. In wind tunnel tests, he opted for flat, extremely thin, short-span trapezoidal (trapezoid) wings, which were proven to produce the lowest wave drag in the supersonic regime.

Cover Photo: Test pilot Herman R. (“Fish”) Salmon with a Lockheed XF-104 prototype parked at Rogers Dry Lake. (Lockheed Martin)

Extreme Engineering in the Wing Profile

Supersonic wave drag is mathematically directly related to the square of the ratio of wing thickness (t) to chord length (c) (t/c²). Accordingly, the thickness-to-chord ratio (t/c) in the F-104’s wing profile was maintained at an extremely low minimum level of 3.36 per cent at both the wing root and the wingtip.

-Wings as Sharp as a Knife: The leading-edge thickness of the wing is just 0.41 mm, making it as sharp as a knife. As this sharpness poses a serious physical hazard to ground crew, special protective covers are fitted to the wings during hangar and apron operations.

-Systems Crammed into the Narrow Fuselage: Owing to the wing’s extremely thin structure, the fuel tanks, armament systems and landing gear could not be housed within the wing; all have been crammed into the aircraft’s narrow fuselage.

-‘Piccolo’ (Flute) Actuators: The hydraulic actuators controlling the ailerons within the wing were designed to be just 2.5 cm thick. Owing to their slender, cylindrical shape, technicians have dubbed these components ‘Piccolo’ (Flute) actuators.

The T-Tail and the ‘Dutch Roll’ Problem

One of the greatest challenges in the aircraft’s flight dynamics was the vertical tail configuration. Wind tunnel tests had made it necessary to mount the stabiliser at the very top of the vertical tail (T-tail) to ensure optimum control along the pitch axis.

However, as the aerodynamic surface area of the vertical tail was almost as large as the main wing span, rudder movements triggered the “Dutch Roll” (yaw oscillation) effect, causing the aircraft to oscillate uncontrollably about its fuselage axis. To dampen this adverse effect, the engineers:

1. Gave the wings a downward-sloping negative dihedral (anhedral) angle.
2. They also added a longitudinal keel (ventral fin) beneath the fuselage to increase vertical stability and ensure supersonic stability.

High Wing Loading and the Solution: BLCS

The extremely narrow wing area has significantly increased the aircraft’s wing loading (W/S) value. In the formula below:

Wing Loading = (W)/(S)

-W: Represents the aircraft’s total weight,

-S: Represents the narrow wing area, approximately 18.22 m².

The high wing loading has dramatically reduced the aircraft’s lift at low speeds, pushing take-off and landing speeds to dangerous levels. To address this structural weakness, the Boundary Layer Control System (BLCS) was developed. This system prevents the airflow from separating from the wing by blowing high-pressure compressor air, drawn from the engine, onto the wing surface when the flaps are extended by more than 15 degrees. Thanks to the BLCS, the aircraft’s dangerous landing speed has been reduced by approximately 20 per cent.

The General Electric J79 turbojet engine powering the aircraft, with its variable compressor stator vanes, continuously optimised the airflow within the engine; this reduced the risk of compressor stall, enabling the aircraft to fly safely at Mach 2 for extended periods.

Chapter 3: The Power of the F-104 Starfighter: The Evolution of the J79 and Propulsion Systems

The Lockheed F-104 Starfighter owes its title of ‘manned missile’ not only to its aerodynamic design but also to its pairing with the General Electric J79, the most revolutionary jet engine of its era. This section of the article examines the F-104’s propulsion systems, from the initial engines used in the aircraft’s prototypes to the rocket boosters employed in astronaut training.

3.1. The Beginning: The Wright J65 and the XF-104

The two XF-104 prototypes, which marked the first steps of the Starfighter project, were not originally designed for the J79—the aircraft’s eventual engine. Due to delays in the J79’s development, these prototypes were fitted with the Wright J65-W-6 (7,800 lb dry thrust), the American version of the British Armstrong-Siddeley Sapphire engine. With the subsequent J65-W-7 variant, the aircraft was able to reach a speed of Mach 1.79 using the afterburner. However, this engine was insufficient to demonstrate the aircraft’s true potential of Mach 2 performance.

3.2. The J79 Revolution: Technical Innovation

The General Electric J79 was the key factor that changed the F-104’s destiny. Compared to its contemporaries, the Allison J71 and the Pratt & Whitney J75, the J79 offered better fuel efficiency and a lower dry weight. The engine’s most notable feature was its automatically variable-angle stator vanes, which prevented stall problems at low speeds and ensured maximum efficiency at high speeds. Weighing approximately 3,500 lb, the J79 could generate over 15,000 lb of thrust with the afterburner engaged, representing a unique power-to-weight ratio for that era.

Lockheed F-104A-5-LO Starfighter 56-742, fitted with a General Electric J79 turbojet engine, circa 1957–59. (US Air Force)

3.3. Engine Variants and Performance

Different variants of the aircraft utilised various versions of the J79 engine to accommodate increasing weight and changing mission requirements:

-J79-GE-3/3A/3B: Used in the YF-104A and F-104A models. Stall problems experienced in the early models were addressed in 1958 with the introduction of the more reliable -3B version.

-J79-GE-7: Powered the F-104C and D models. The turbine diameter was increased by 2 inches, raising the thrust to 15,800 lb.

-J79-GE-11A: Developed for the F-104G, NATO’s standard model. Production of this engine in Europe was carried out under licence by BMW (Germany), Fabrique Nationale (Belgium) and Fiat (Italy).

-J79-GE-19: Used in the F-104S and the modernised ASA models, which were the most advanced versions of the Starfighter. With a dry thrust of 11,870 lb and an afterburner thrust of 17,900 lb, it enabled the aircraft to reach a speed of Mach 2.2.

3.4. Characteristic Sound: ‘Moose Call’

One feature of the F-104 engine that became legendary amongst pilots and technicians was the sound it produced. The sound, caused by the rapid repositioning of the engine’s inlet guide vanes, was likened by Canadian pilots to the bellow of a moose during the rutting season and dubbed the “Moose Call”. When the engine speed was reduced for landing, the airflow passing through the air bleed valves produced an otherworldly whine.

3.5. Pushing the Limits

The NF-104A and Rocket Engines The Starfighter’s propulsion system was not limited to just the jet engine. The NF-104A models used by NASA and the USAF for astronaut training featured a Rocketdyne AR-2 liquid-fuelled auxiliary rocket engine mounted at the root of the vertical tail. Providing an additional 6,000 lb of thrust, this system enabled the aircraft to climb to record altitudes of 120,800 feet (approximately 36,800 metres), where the atmosphere is extremely thin.

3.6. Operational Challenges and Safety

Despite its power, the early days of the J79 were fraught with difficulties. In particular, the afterburner’s instantaneous activation—rather than a gradual one—propelled the aircraft directly from Mach 1 to Mach 2.2, making it difficult for pilots to maintain stability at these speeds. Furthermore, bird strikes during low-altitude flight caused the engine to stall completely; for the single-engined Starfighter, this situation almost invariably resulted in a fatal crash. Consequently, the F-104’s engines have taken their place in aviation history as an engineering marvel that pushed the boundaries of jet technology, making Mach 2 speeds routine, whilst simultaneously demanding a high degree of discipline and expertise.

F-104 Variants Engine Configuration Table

Variant Engine Model Notes and Performance Details

XF-104 (Prototype) Wright J65-W-6 This was the initial engine used in the aircraft’s first two prototypes.

YF-104A / F-104A / B General Electric J79-GE-3 / 3A / 3B These are the first production-series engines; with an afterburner, they provide approximately 14,800 lb/st of thrust.

F-104C / D General Electric J79-GE-7 A more powerful version, optimised for multi-role missions.

F-104G / RF-104G / TF-104G: The General Electric J79-GE-11A is the standard engine for the ‘Super Starfighter’. It produces 15,800 lb/st (7,173 kgp) of thrust.

CF-104 / CF-104D Orenda J79-OEL-7: An engine similar to the J79-GE-7 variant, manufactured under licence by Orenda in Canada.

F-104J / DJ J79-IHI-11A: A J79-GE-11A equivalent engine, manufactured under licence by Ishikawajima-Harima in Japan.

F-104S / ASA / ASA-M J79-GE-19 or J79-GE-J1Q: The most powerful J79 variant. Manufactured in Italy by Fiat and Alfa Romeo; it provides 7,900 lb/st (8,120 kgp) of thrust.

NF-104A (Flight Training) J79-GE-3B + Rocketdyne LR121-NA-1 Hybrid configuration; in addition to the standard jet engine, it features a rocket motor in the tail providing an additional 6,000 lb of thrust.

Notable Engine Modernisations:-Pakistani F-104As: Pakistan’s F-104As were subsequently modernised with the more powerful J79-GE-11 engines. -Special Mission A’s: Some F-104A’s were fitted with J79-GE-19 engines (17,900 lb/st) for high-altitude interception missions. -The Importance of the J79: This highlights the vital role played by the J79 engine in enabling the F-104 to reach Mach 2 speeds and in giving the aircraft its ‘human missile’ character.

E-5071J F-104A (Serial No: 56-0749), on the runway at the NASA Flight Research Centre (now the Dryden Flight Research Centre) at Edwards Air Force Base. The aircraft is shown with an Air-Launched Sonic Rocket (ALSOR) attached to its underside. NASA test pilot Milton O. Thompson was ejected from this aircraft on 20 December 1962 after the jet became uncontrollable due to the asymmetrical deployment of the ailerons. 16 December 1959 NASA Photograph  
Technical Revolution, Aerodynamic Limits and Boundary Layer Control

The key driving force behind the F-104 Starfighter’s ability to achieve sustained flight beyond the Mach 2 speed limit is the General Electric J79 axial-flow turbojet engine.

The first XF-104 prototypes were flown with Wright J65-B-3 engines without afterburners, as the J79 engine was not yet ready; this limited the aircraft’s maximum speed to Mach 1.79. However, the integration of the J79 engine completely transformed the technical parameters. General Electric engineers developed an innovative solution to prevent the compressor vanes from stalling at high compression ratios (12.2:1 to 13.5:1). This solution involved the use of automatically adjustable stator vanes (variable stator vanes) in the first seven stages of the compressor. Consequently, the engine was able to operate with extremely high efficiency and low weight via a single shaft, without the need for complex twin-shaft designs. The J79-GE-11A variant used in the F-104G model produced a thrust of 45 kN (4,535 kg) in dry power mode and 70.28 kN (7,165 kg or approximately 15,600 lbf) with the afterburner engaged. With a take-off weight, including fuel, of approximately 20,000 pounds (9,070 kg), the aircraft possessed climb and acceleration capabilities that were unique for its era, justifying its nickname ‘The Missile with a Man in It’. However, this high engine performance also brought with it systemic issues; indeed, in February 1958, the first production models—the F-104A aircraft—were temporarily grounded due to technical faults in their J79 engines and were only granted flight clearance following the J79-GE-3B engine overhaul. The aircraft’s extremely small wing area, whilst minimising drag at high speeds, resulted in a serious lack of lift during low-speed manoeuvres such as take-off and landing 5.
 To overcome this chronic weakness, a ‘Blown Flap’ system, known as Boundary Layer Control (BLC), was introduced on the aircraft. Operating on the principle of a “Bleed Air Supply System”, this mechanism drew high-pressure, high-temperature air from the compressor stage of the J79 engine. This hot air was first passed through a primary heat exchanger, where it was cooled to a nominal temperature of 2880 C for in-cabin air conditioning and cockpit pressurisation, and to 177 0 C for fuel tank pressurisation and transfer.

When the flaps were extended beyond a certain point, this hot, high-pressure air drawn from the engine compressor was blown out at high speed through millimetre-wide slots (whose widths ranged from 0.5 per cent to 2 per cent of the wing chord) located on the upper surface of the flaps, via titanium plenum tubes within the wing. Thanks to the Coandă effect, this layer of air adhering to the flap surface re-energised the boundary layer, thereby preventing flow separation and artificially increasing the lift coefficient. Thanks to this system, the F-104 was able to land at speeds that could be considered reasonable, despite its small wings. However, as this hot airflow caused severe erosion of the wing metal, the upper surfaces of the wings were coated with a special white epoxy protective paint. The systemic risk was that, in the event of a drop or stoppage in engine speed during the landing approach, the BLC system would fail instantly; in such a scenario, the aircraft’s lift would be reduced to zero and it would crash to the ground like a stone.

The Pitch-Up Phenomenon and Automatic Control Systems

The F-104 Starfighter’s most controversial major structural issue—and the direct cause of many fatal accidents—is the ‘Pitch-Up’ (uncontrolled sudden nose-up) phenomenon. The aircraft’s wing loading reached an extremely high value of 150 lbs ft² at maximum weight, which was even higher than that of a massive Airbus A380 passenger aircraft. During manoeuvres carried out at high angles of attack (alpha 150 C), the turbulent, low-energy airflow (wake) separating from the aircraft’s slender wings and fuselage completely enveloped the horizontal stabiliser located at the very top of the high T-tail configuration.

Exposed to this turbulent flow, the horizontal stabiliser was unable to generate the aerodynamic downforce required to keep the aircraft’s nose down. Having lost its stability, the aircraft, with its aerodynamic moment balance disrupted, would jerk its nose upwards within a fraction of a second, raising its angle of attack to as high as alpha 600 C. From this stage onwards, the aircraft would completely lose its directional stability and begin to oscillate laterally and vertically (lateral/directional oscillation), before entering a ‘flat spin’ characterised by uncontrolled oscillation and deviation. In this position, a Starfighter would become an uncontrolled mass, with its aerodynamic controls rendered completely ineffective, losing altitude at a rate of 12,000 to 15,000 feet (3,700–4,600 metres) per minute. To counter this fatal flaw, the aircraft was fitted with an Automatic Pitch Control (APC) system. The APC system continuously monitored data from the angle-of-attack sensors during flight. When the critical pitch angle was approached, the system would initially warn the pilot by activating a mechanical vibrator on the control stick, known as a ‘stick shaker’. If the pilot ignored this warning and continued to push the angle of attack, the ‘stick pusher’ mechanism would engage, using hydraulic and mechanical force to push the control stick forward with a force exceeding the pilot’s muscle strength, thereby forcibly lowering the aircraft’s nose to a safe angle. However, during combat manoeuvres or low-altitude flights, the manual deactivation or override of this system by pilots—despite explicit prohibitions in the flight manuals—became a widespread practice and paved the way for numerous fatal accidents.

Second-generation design project

An F-104 derivative; featuring wider wings and a high-wing configuration. Never entered production.    CL-704 VTOL    Vertical take-off and landing (VTOL) attack aircraft    A project that remained on the drawing board, featuring engine pods at the wing tips.In summary: The Starfighter began its career as a simple daytime interceptor (A); it evolved into NATO’s multi-role standard fighter (G), then into an Italian defence platform (S/ASA) with radar and missile capabilities maximised, and even into astronaut training vehicles (NF) capable of flying at the edge of space. 47 This brings us to the end of the first part of our series. See you in the second part. The bibliography will be provided in the final part of the series.