37° Stormo

English translation

The F 16 Fighting Falcon is a combat aircraft developed by General Dynamics, which has now been absorbed by Lockheed Martin. The original concept was intended to be a light weight fighter, and subsequently came to be considered as a multi-role aircraft. Its versatility has led it to become without doubt the largest aeronautical project since the beginning of aviation history. The numbers speak for themselves: more than 4,400 aircraft constructed, sold to 25 different nations, and so effective and capable that in the 33 years since production commenced in 1976 it has been continually upgraded and developed, and still achieves market successes on a global level.
The origins of the programme can be traced back to the mid-sixties, initially in a concept known as ADF (Advanced Day Fighter), a light aircraft weighing around 11.300 kg intended to outclass the performance of the then feared Soviet-built MiG 21 Fishbed: this project was subsequently abandoned after the appearance of the powerful Mig 25 Foxbat. By the end of the sixties, however, the projects for a new medium dimension fighter returned to the forefront. The first funding, albeit limited, was divided between General Dynamics and Northrop, funds which were assigned to the two well-known manufacturers for the design of a combat aircraft which was small, light, low drag, and carried no bombs. The designations assigned to the projects were YF 16 for General Dynamics, and YF 17 for Northrop.
Despite the hostility of the backers of another project for a fighter of larger dimensions which was under full development, the FX (the basis of the future F 15 Eagle), the ADF programme, subsequently re-designated F-XX, gained the support of the then Secretary of Defence, David Packard.
In May 1971 the first six proposals materialised, and of these only two were accepted, and amongst the two judged as valid was that denominated Lightweight Fighter (LWF). At this point the RFP (Request For Proposals) were emanated, which were sent to the manufacturers in the sector in the January of the following year.
Five manufacturers responded to the request, and in March 1972 the winners of the prototype development contact were announced: these were Boeing with the 908-909 model, and General Dynamics with the model 401; unfortunately for Boeing, it was later relegated in favour of Northrop, who only at later stage delivered a project designated P 600 which was considered to be more responsive to the contract terms than the Boeing offering. Once the final requirements had been defined, the two manufacturers formalised the contracts for the production of the prototypes, with the first flights planned for the beginning of 1974.
The first flight of the YF 16 actually took place on 2 February 1974 at the Air Force Flight Test Center at the Edwards AFB in California, and lasted some 90 minutes. The first supersonic flight was completed three days later. The wheels of the second prototype left the runway on 9 May, while its direct rival, the YF 17, commenced flying after a few weeks’ delay. The YF 16 performed a total of 330 flights totalling 417 flying hours.
At this point the LWF project became a probable, but not certain, acquisition project for the United States Air Force, a factor that could have still heavily damaged the programme. In the meantime, other members of NATO (Belgium, Denmark, Holland and Norway) recognised the requirement to replace the by now outdated F 104G Starfighter with a new fighter. Moreover, there remained a strong desire amongst these nations to retain the possibility to manufacture the aircraft under licence, as had occurred with the previous aircraft. In 1974 an important compromise was achieved that kept the project alive: the four nations further pressed the United States to agree to the initiation of series production of the new fighter, but specifying as a primary clause that the USAF would have ordered the aircraft as winner of the LWF competition, thereby guaranteeing the purchase of a few hundreds of aircraft, despite the fact that the USAF was not particularly interested in a complementary combat aircraft. Another fundamental step made by the four nations was the creation of the "Multinational Fighter Program Group", which continued to put significant pressure on the United States to accelerate the decision planned for May 1975. Thanks to this pressure this decision was, however, brought forward to the December of the preceding year, and gave further impetus to the test phase. Another step which boosted the LWF programme was a plan conceived by the US Congress which sought to achieve a greater convergence in equipment supply to the Air Force and Navy, thereby bypassing minefield of controversy that had accompanied the lifetime of the LWF project and set it against the FX project, now no longer considered a competitor, but more as complementary.
Finally on 11 September 1974 the USAF confirmed its plan to acquire sufficient aircraft to equip five TFW (Tactical Fighter Wings), and subsequently, on 13 January 1975, the Secretary of the Air Force announced the victory of the YF 16. The principal advantages that opened the door to the future Fighting Falcon were the lower operational costs and better performance than those of the YF 17. A prime factor which gave additional value to the programme was the selection of the Pratt & Whitney F 100 engine, the same as fitted in the F 15, which notably reduced the costs of the programme.
The development phase was initially planned to involve 15 aircraft, but was subsequently reduced to 8, flying as “Full-Scale Development” aircraft for the test programme, while production commenced in late 1975 at the General Dynamics factory at Forth Worth in Texas. The first example, an F 16A, made its first flight on 8 December 1976, while the first two-seat (F 16B) flew on 8 August of the following year. The first production F 16A flew in 1878, and deliveries commenced in the following year, with operational service commencing at the start of October 1980, the nit involved being the 388°Tactical Fighter Wing at Hill AFB.
In the light of potential exports, the aircraft was also offered to the air forces of America’s NATO allies, and the first presentation of the aircraft outside the USA occurred during the Paris Air Salon of 1975. In accordance with the agreements, the MFPG consortium kept up the effort expended during the development phase by obtaining a signature on a purchase contract for 348 examples, also facilitating assembly of the aircraft in Belgium. This important contract additionally arranged for some components of the aircraft to be manufactured by companies on the old continent. Deliveries were scheduled to commence in 1979. The base A and B versions were replaced in the early eighties by the C and D developments, which offered improvements in both engine and avionics. Further and continuing developments have continued over the years, and are represented by an increasing number of variant “Block” numbering.
In 1993 General Dynamics ceased F 16 activities, and the project, now reaching its evolutionary apex, was passed to Lockheed Martin. Under this new brand the new E, F and I versions were developed, which today continue to achieve successes, but only on the export market.
The F 16A is a supersonic multi-role tactical single-engined aircraft, designed to be a relatively economical aircraft to be used for many types of mission, and to be easily maintained at readiness for operations. It is smaller and lighter than its predecessors but features aerodynamics and avionics systems that are more advanced. Amongst other factors, it was the first combat aircraft to utilise the fly-by-wire system, and thanks to which its performance has been capable of notably augmentation. Very agile, the F 16A can sustain load factors up to + 9 G and -3.5 G, and achieve a maximum speed greater than Mach 2.
The airframe of the F 16 has a fairly simple and traditional structure, and is very light. The air intake is simple, and does not feature any system to vary the entry of the airflow, while the wing is a delta with an elongated leading edge. These extensions, known as LEF, serve to augment the handling, while the tips feature launch rails on which air-to-air missiles can be installed.
There is a single fin of not particularly large dimensions, but which is supported by two rear ventral strakes which have a notable impact as surfaces, an unusual feature on fighters of Western manufacture, but a classic design element on Soviet aircraft.
The engine initially fitted in the early “16s” was the Pratt & Whitney F100-PW200 turbofan, a lightly modified version of the F100- PW100 model installed in the F 15. This version, utilised on the A and B models up to Block 25, delivered 106 KN thrust. Those examples of the Block 15 which have gone through the “Operational Capability Update” now feature the F100-PW220, delivering thrust similar to the preceding version. This latter version was also utilised in the Block 32 and 42, and features a component called DEEC (Digital Electronic Engine Control), which manages the engine and increases its efficiency.
As basic armament, the Falcon is equipped with an M 61 Vulcan 20 mm cannon, sited above the left wing root. The early models could carry up to six heat-seeking AIM 9 Sidewinder air-to-air missiles, attached to various under-wing pylons, while some variants can utilise the radar-guided AIM 7 Sparrow: the most recent versions can also be equipped with the AIM 120 AMRAAM. The ten under-wing and under-fuselage points can accept air-to-air missiles, a wide variety of air-surface missiles, rockets or bombs, electronic countermeasures pods, navigation pods, target identification pods, or armament containers.
The F 16 was designed to be less costly and far simpler to maintain than its predecessors. The fuselage is constructed from 80% aeronautical alloy, 8% in steel, 3% in composite materials, and 1.5% from titanium. The flying control surfaces, like the flaps, slats, and ventral strakes, and manufactured using aluminium honeycomb structures, and covered in epoxy resin skin reinforced with graphite. The F 16 possesses 228 access panels distributed around the aircraft, 80% of which can be reached by engineers without the use of steps. The number of lubrication points, external power couplings, and replaceable modules, has also been reduced in comparison with aircraft of preceding design generations.
This was, moreover, the first aircraft intentionally designed to be slightly aerodynamically unstable. This technique, known as relaxed static stability, was utilised to further improve the manoeuvring performance of the aircraft. The greater part of the aircraft was designed with positive static stability, which recovers the aircraft to its previous aspect in the event of a variation. However, positive stability obstructs manoeuvrability, as the tendency to maintain aspect opposes the input forces from the pilot, who wants to modify it. On the other hand, and aircraft with negative stability, in the absence of control departs quickly from controlled and level flight. For this reason, an aircraft with negative stability will always be more manoeuvrable. At supersonic speed, the aircraft offers greater stability through the aerodynamic forces, while at subsonic speed the aircraft is always on the brink of a loss of control.
To control the tendency of the aircraft to auto-depart from a stable aspect, and to relieve the pilot from the necessity to continually counterbalance this with the controls, the F 16A possesses a four channel fly-by-wire system. The flight controls computer, the key component in the system, detects the control inputs made by the pilot with the control column and rudder and transmits them to the control surfaces to produce the manoeuvre required by the pilot without losing control of the aircraft. Every second the computer performs thousands of evaluations of the aspect of the flight and effects automatic corrections to counterbalance the deviations from the aircraft course that have not been input by the pilot, delivering stable flight.
The computer incorporates a series of limiters which control the movement in the three principal axes on the basis of the aspect of the aircraft, the speed, and angle of attack, impeding the movement of the control surfaces which could generate instabilities such as a sideslip or tail slide, or an excessive increase in the angle of attack which could provoke a stall. The limiters, moreover, ensure that the pre-defined acceleration limits are not exceeded.
While in the A and B variants the system relies on analog electronic components, in the F 16C/D Block 40 and on subsequent versions this has been replaced by a digital system.
From a pilot’s point of view, one of the most evident characteristics of the F 16 is the exceptional visibility from the cockpit, a vital factor during air to air combat. The bird-strike resistant polycarbonate canopy provides 360° vision, with 40° lower vision to the sides and 15° below the nose (in comparison with the 12-13° of its predecessors). The pilot’s seat is installed in a higher position. Moreover, the canopy is constructed as a single piece, without joints or rims that could obstruct the view of the pilot. Only in the two-seat version is a reinforcement rim present to create an obstruction, designed in due to the length of the canopy.
The pilot controls the aircraft principally through a joystick mounted on the right hand arm rest (instead of the more common central position), and uses an engine throttle control on the opposite side; conventional pedals are fitted for rudder control. To improve handling in high-G manoeuvres, many controls are brought together, and made available on two control groups positioned on either side. This system is known as HOTAS (Hands on Throttle and Stick). Light pressure by hand on the controls provokes the transmission of electric signals through the fly-by-wire system to the various control surfaces. Initially the joystick was fixed, but this solution was quickly revealed to be uncomfortable and difficult for the pilot to manage, and so a certainly level of "play" was inserted into the handle. Since their introduction with the F 16, HOTAS controls have become standard in modern combat aircraft. The cockpit possesses a Head up display (HUD), which displays the flight and combat information through icons and symbols in front of the pilot without obstructing the visibility. Being able to keep the head above the line of the cockpit combing, this system improves the awareness of the pilot of the situation developing around him.
A further evolution which provides the pilot with better situational awareness is delivered by the multifunction display. The left hand display is the primary display, and generally shows maps and radar-derived data, while the right-hand screen presents system information, providing fundamental engine, undercarriage, flap and slats, fuel quantity, and armament state information.
Another particular of the Fighting Falcon is the ACES II seat, an ejector seat reclined at an angle of 30° to improve the pilot’s tolerance of high acceleration forces, reducing the probability of a loss of consciousness. This configuration has to be associated with a head support which assists in avoiding neck pain. Subsequent aircraft designers have reduced this angle to 20°.
In terms of the F 16’s radar equipment, the original A and B versions were fitted with the AN/APG-66 manufactured by Westinghouse (today Northrop Grumman). The antenna array is compact enough to be housed in the relatively small radome of the aircraft. It possessed four operational frequencies in the X band (8-12 GHZ), offering four air-air combat modes and seven air-surface combat modes, also usable by night or in bad weather.
Subsequent versions, beginning from the Block 15, use the AN/APG-66(V)2 radar, featuring a new and more powerful processor, greater reliability, and increased range in a disturbed radar environment or in the presence of radar countermeasures. Another upgraded version is the AN/APG-66(V) 2A offering a further increase in speed and memory.
Remaining on the theme of avionics, the fighter’s equipment includes an ALR radar alarm, a radar altimeter, UHF/VHF radios, IFF, while the aircraft can also be fitted with ECM pods such as the ALQ 119, ALQ 131 and the ALQ 184. For active defence, the aircraft carries radar “Decoy” launchers sited on the exterior of the rear fuselage.
The version acquired through the leasing accord by the Aeronautica Militare is that designated ADF (Air Defence Fighter). From 2003, the Aeronautica Militare received 34 aircraft, 30 in single seat version, and four in two-seat configuration, and they were issued to three Gruppi di Volo, the 23° Gruppo of the 5° Stormo at Cervia, and the 10° and 18° Gruppo of the 37° Stormo at Trapani Birgi. The single seat aircraft serving at the Trapani base, and at Cervia, are configured to standard “Block 15 Falcon Up”, and the operational conversion versions are “Block 10”: all had previously served with units of the ANG.
The ADF version was ordered by the USAF to re-equip the Air National Guard air defence units in the Northern sector. In 1986 more than 270 examples of the F-16A and B from Blocks 15 and 10 were upgraded and modified with avionics optimised for this specific role, and were, furthermore, configured to carry the semi-active radar-guided AIM 7 Sparrow missile. This modification was carried out at the Ogden Air Logistics Center at Hill AFB in Utah.
The modification which differ the ADF version from the original model are fairly evident, commencing with the antennae positioned on the upper surfaces just ahead of the canopy and on the under surfaces just below the air intake: these antennae, known as “bird-slicers”, are part of the advanced AZ/APX-109 Mk.XII AIFF (Advanced Identification Friend or Foe) system supplied by Teledyne/E-System. The other feature that characterises the ADF variant is the two “bulbs” which protrude from either side of the base of the fin. This modification was made necessary by the requirement to install the single band Bendix King AN/ARC-200HF/SSB single band HF (High Frequency) radio. In actual fact, the protuberance had been created to house the two actuators of the rudder, which have been moved to give accommodate the antennae. These characteristics are specific to the ADF version, while the B ADF version houses only the identification system, and not the HF antenna.
Moreover, the ADF carries the Westinghouse AN/APG-66(V) 1 radar, with “Look-down/shoot-down” capability, an upgraded version which possesses the capability to illuminate a target at which to aim the semi-active guided AIM-7 Sparrow missile.