Genesis and development of the Italo/Brazilian AMX; a new star is born in the strike aircraft firmament.
A New Star is Born in the Strike Aircraft Firmament
The widespread acceptance of the Douglas A-4 Skyhawk suggests that there is a market for a dedicated attack aircraft with no air-to-air capability, provided that the price is right. On the other hand, the general rejection of the BAe Harrier and Vought A-7 (both technically attractive aircraft) and the limited success of the Sepecat Jaguar, which is still being assembled in India, imply that there is a very rigid ceiling to the amount that most air forces are willing to pay for this class of aircraft.
In developing what may fairly be described as the only new Western attack aircraft in almost two decades (the Fairchild A-10 having flown in 1972), with the AMX the Aeritalia/Aermacchi/Embraer team has thus taken a calculated risk. It may be that potential customers will soldier on with old combat aircraft or with derivatives of advanced trainers, such as the Hawk and Alpha Jet. On the other hand it is also possible that, with the right kind of political backing, the marketing team of AMX International will sell (as they predict) around 350 aircraft on top of the domestic total of 317-331.
Requirements and Workshare
Although all three companies had made privately funded project studies of attack aircraft some years earlier, the AMX programme formally began with the issuing of an operational requirement by the Italian Air Force in 1977. In April 1978 Aeritalia and Aermacchi agreed to undertake joint design studies and market assessments. In 1979 the two companies were awarded a project definition contract with a view to developing an aircraft that would replace the service's remaining G.91s and F-104s. In the meantime the Brazilian Air Force had developed a requirement for a similar aircraft with only minor equipment differences. In April 1980 the development phase began, and two months later the Italian manufacturers signed an agreement with Embraer that allowed for Brazilian participation in the AMX programme. A formal Memorandum of Intent between the two governments was signed in March 1981.
It was established at the outset that Italy would have 187 aircraft and Brazil 79. At this stage only a single-seat AMX was planned by the two air forces, although the manufacturers may well have had other ideas. In order to eliminate the need for money to flow between the countries (and thus to avoid problems with varying exchange rates), it was decided that Italy would perform 70.3 per cent of the work and Brazil the remaining 29.7 per cent. Within Italy, Aeritalia would carry out two-thirds of the Italian share of the programme, i.e. 46.9 per cent, and Aermacchi one-third or 23.4 per cent.
The agreement included the construction and testing of six prototypes, of which four would be assembled in Italy and two in Brazil.
In order to provide the correct workshares, Aeritalia was given responsibility for the centre fuselage, tail surfaces, ailerons and spoilers, while Aermacchi was allocated the front fuselage and rear fuselage, and Embraer the wings, air intakes, pylons, drop-tanks, reconnaissance pallet and undercarriage. Embraer is also responsible for the twin DEFA 554 cannon installation of the Brazilian version, the Italian version having a single GE M61 Vulcan gun offset to the left.
Details of the operational requirement have not been published, but it is believed that AMX had to be able to deliver a 6000 lb (2720 kg) bombload over a LO-LO radius of 200 nm (370 km), using only internal fuel and carrying two AIM-9 Sidewinders for self-defence. Aside from the attack role, the AMX was to be suitable for the light reconnaissance role, in the Italian case acting as a complement to the much heavier Tornado.
The requirement also placed considerable emphasis on wartime survivability. This involved a high degree of systems redundancy, so that AMX could continue the mission despite considerable damage. Internal ECM equipment was also required, leaving the pylons free for weapons and fuel tanks. A reasonably short airfield performance was demanded, so that some degree of runway bombing could be survived. It was further specified that the powerplant should not use an afterburner, in order that the infrared signature should be as small as possible.
The aircraft that was designed to meet this requirement is externally quite conventional, rather like a small A-7, but with two lateral intakes instead of the single chin inlet of the Vought design, which is more prone to ingesting debris and groundcrew. In size it is half-way between the A-4 and A-7, with an empty weight of 14770 lb (6700 kg) and a clean take-off weight of 20750 lb (9410 kg). These figures are approximate, and vary with the equipment fit. The AMX has already flown at a take-off weight very close to 28665 lb (13000 kg), implying an external load of around 8000 lb (3600 kg) with full internal fuel. Wing area is 226 sq ft (21 [m.sup.3]).
The AMX is powered by a single Rolls-Royce Spey RB.168-807 turbofan of 11030 lb (5000 kg) thrust. The Spey is a moderate-bypass engine, providing an attractive combination of low cost, high reliability and export potential. The first of 5500 Speys entered service in 1964, and total running time is now approaching 40 million hours. The Mk. 807 began testbed running in June 1980, and was certificated in 1982. The manufacture of these engines for AMX is gradually being transferred from Rolls-Royce to Fiat and Piaggio in Italy and CELMA in Brazil.
The first prototype aircraft (A.01, serial MM X594), had its maiden flight on 15 may 1984, but was written off as the result of an engine surge while approaching to land at the end of its fifth flight, on 1st June. The pilot (Manlio Quarantelli, Aeritalia chief test pilot) ejected, but died as a result of his injuries. The engine was subsequently modified to increase the surge margin, and no further problems have been experienced, though the aircraft has been flown to an angle of attack of 45 degrees. The first prototype was replaced by a substitute designated A.11. First flight dates for the prototypes are listed below:
First Flights of Prototypes
A.01 MM X594 15. 5.84 A.02 MM X595 19.11.84 A.03 MM X596 28. 1.85 A.11 MM X597 24. 5.85 A.04 4200 16.10.85 A.05 MM X599 26. 7.86 A.06 4201 16.12.86
As indicated by their serial numbers, prototypes A.04 and A.06 were assembled and flown in Sao Jose dos Campos. Aermacchi was responsible for A.02 and A.05. In the context of development flying, it may be noted that Quarantelli was replaced by Egidio Nappi and later by Napoleone Bragagnolo. Aermacchi's CTP is Riccardo Durione, and Embraer's CTP is G.P. Schittini, replacing L. Cabral.
Aside from the minor engine changes referred to earlier, few modifications have been made to the aircraft as a result of flight development. Lateral control at high Mach numbers required some improvement, which was obtained by adding five vortex generators to the leading edge slats on either side. It was also found that there was a reduction in longitudinal stability over a small angle of attack band at speeds around Mach 0.90, but this was eliminated by an automatic spoiler extension to 10 degrees.
In 1986 it was decided to go ahead with a two-seater version. The first prototype is due to fly at Caselle (Turin) around October, with the second following at Venegono (Milan) later in the year, and the third at Sao Jose in May 1990. It is anticipated that only 30-35 flights will be required to clear the two-seater, since it differs very little from the single-seater in external shape.
In effect the addition of a second crew member displaces the air conditioning system to the reconnaissance equipment bay in the lower fuselage, and deletes the front fuel tank. Maximum fuel load for the AMX is 6150 lb (2790 kg) internally, but this is more than enough for the Italian mission, hence the two rear fuel tanks of the single-seater are deleted. In the case of the Italian two-seater the loss of the forward tank can thus almost be offset by reinstating the two small rear tanks.
One result of minimising the external change is that the rear pilot cannot see over the front Martin-Baker/SICAMB ejection seat. To compensate for this, the rear pilot will have a Ferranti multi-function display acting as a repeater from a video camera on the front OMI/Selenia HUD. It is expected that it will be possible to land the aircraft from the rear cockpit. Full operational clearance is expected to be obtained on the same time-scale as the single-seater, i.e. at the end of 1990.
The two-seater will naturally be more expensive, and this has caused some problems in restructuring the programme. As matters stand Italy is to have 51 two-seaters in addition to its 187 single-seaters, and Brazil will have 14 two-seaters while reducing its single-seat buy to 65. However, it is accepted that these numbers would distort the worksharing, and that some refinement will be necessary.
At time of writing the first two production batch contracts have been signed (for 30 and 84 aircraft), and a third (for 78 aircraft) is due to be signed shortly. The production breakdown is as follows:
single-seaters: 19 8 two-seaters: 2 1
single-seaters: 53 22 two-seaters: 6 3
single-seaters: 37 15 two-seaters: 19 7
The first production AMX (serial MM 7089) had its maiden flight at Caselle on 11 May 1988 with Egidio Nappi at the controls. The second was flown by Riccardo Durione at Venegono on 26 September 1988. By end April six production aircraft had flown, and are due to be delivered to the Reparto Sperimentale Volo at Practica di Mare for intensive flying trials. The first operational unit will be the 103 [degrees] Gruppo at Istrana. The first production aircraft from the Embraer line (Serial 5500) had its maiden flight on 12 August, and three Brazilian aircraft are due to be delivered this year. The first operational unit, the 16th Aviation Group, will be based in Santa Cruz in the state of Rio de Janeiro.
Survivability being of paramount importance, various camouflage schemes were tested on the prototypes. The Italian production aircraft will be painted pale grey and the Brazilian paint scheme is light grey to the wing line and medium grey on the upper surfaces.
The AMX has an excellent degree of systems redundancy. Navigation is based on a Litton LN-39 INS, with two-axis gyro and air data for backup. The Brazilian version also has TACAN, VOR/ILS, DME and ADF, but of these radio aids the Italian version has only TACAN, with provision for MLS to be added. Navigation, weapon-aiming and the flight control system are based on two Aeritalia computers.
The rudder is operated by duplicated FBW, with duplicated hydraulics, though no manual reversion, hence deadstick landings are crosswind-limited. The ailerons are pushrod-operated by actuators mounted over the engine, and have manual reversion. The four spoilers are FBW-operated. The tailplane is also FBW-operated, while the elevators are cable-operated with manual reversion. Accumulators provide emergency hydraulic power for undercarriage extension, wheel-brakes, nose-wheel steering and anti-skid, but not for flap deflection. Survivability also benefits from the fitting of the Elettronica ELT/553 self-protection jammer and four chaff-flare dispensers.
With a load of eight 240 kg Mk. 82 bombs, the AMX has a LO-LO radius of 220 nm (410 km), or a HI-LO-LO-HI radius of 310 nm (575 km). With two 450 kg. 83s and two 242 Imp. gal. (1100 litre) tanks, these radius figures become 430 nm (800 km) and 630 nm (1170 km) respectively.
Three types of reconnaissance pallet, including one with a long-range Zeiss camera, have already been cleared. Future equipment developments include the TIALD (Thermal Imaging Airborne Laser Designator) pod, in which Aeritalia is teamed with Ferranti, GEC Sensors and British Aerospace. Flight trials with the FIAR Grifo-ASV search radar in place of the same company's Pointer ranging radar will begin in late 1990. The Brazilian version will begin life with laser-ranging, but a new radar is being developed by Technasa and SMA. For the longer term, an upgraded Spey and other engine options are being considered.
In summary, the Italo/Brazilian AMX is an effective attack aircraft with considerable sales potential, if the price is right.
PHOTO : The AMX in low-speed configuration. Note the twin store locations under the fuselage. Twin
PHOTO : internally-mounted 30 mm DEFAs identify it as an Italian type.
PHOTO : The first Brazilian prototype. The bulge under the fuselage just ahead of the engine
PHOTO : intakes is a reconnaissance pallet containing a Zeiss mapping camera.
PHOTO : The Ferranti TIALD (Thermal Imaging Airborne Laser Designator) pod under the inboard pylon
PHOTO : allows the AMX to launch a variety of laser-guided glide bombs.
PHOTO : Wingtip stores are generally used for short-range air-to-air missiles. This sequence shows
PHOTO : the launch of an AIM-9.
PHOTO : The AMX has a total of four underwing hardpoints plus one under-fuselage point. With twin
PHOTO : or triple carriers, it has a maximum load capacity of 3800 kg.
PHOTO : Frontal view clearly shows the two DEFA muzzles. Brazilian models have one 20 mm General
PHOTO : Electric M 621 gun.
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|Title Annotation:||Aeritalia/Aermacchi S.p.A./Embraer S.A. team's attack plane|
|Date:||Oct 1, 1989|
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