RAAF Lead-in Fighter – Aermacchi MB-339FD

The MB-339 emerged in the mid 1970s as a successor to the MB-326. The first of two MB-339X prototypes flew for the first time on August 12, 1976, while deliveries of initial production MB-339As to the Italian Air Force began in 1979. The MB-339 is based on the MB-326 and retains the same basic wing and rear fuselage. The most obvious change is the MB-339’s new forward fuselage with stepped tandem cockpits, which overcomes the very limited forward visibility of the MB-326’s rear seat (the 339’s rear seat is 32.5cm/13in higher than the front seat). Other aerodynamic changes include a larger fin and two ventral strakes, one either side of the rear fuselage. The wing leading edge was reprofiled and the wing features six hardpoints designed for a variety of weaponry ranging from 500lb bombs to Sidewinder AAMs, gunpods (with 30mm DEFA cannon) and fuel tanks.

Like the MB-326, the MB-339 is powered by a Rolls-Royce Viper turbojet. Aermacchi looked at fitting the 339 with a more modern turbofan, or even two turbofans mounted side by side. Instead an uprated and improved Viper (developed by Rolls-Royce and Fiat Avio) was selected despite a small fuel consumption penalty because of the engine’s simplicity, low initial cost, maturity and good hot and high performance.

The basic MB-339 model is the MB-339A, which has been sold to the air forces of Italy, Malaysia, Nigeria, Dubai and Peru, and the Argentine Navy (some of which saw service in the Falklands War being used for light strike, although with minimal effect). Lockheed and Aermacchi offered a development of the MB-339 dubbed the T-Bird II to meet the US Air Force/Navy’s JPATS trainer requirement (won by a modified PC-9, the Beech Mk II). A single seater, the MB-339K Veltro 2, was flown in prototype form but not ordered into production.

The improved MB-339C flew for the first time on December 17, 1995. The C features an uprated Viper 680, a laser rangefinder in the nose, modernised avionics including a single multifunction display in each cockpit, head up displays and radar warning receivers mounted in the tail. New Zealand was the only MB-339C customer, ordering 18 for $NZ266m in 1990. These were delivered from 1991 and serve with 14 Squadron based at Wigram.

The MB-339FD (FD = Full Digital), as is on offer to the RAAF is the most advanced development of the basic MB-339. Based on the MB-339C with the same engine and many common systems, the MB-339FD was designed for advanced/lead-in fighter training for forthcoming modern fighters such as the Eurofighter 2000. The MB-339FD was developed primarily in response to an Italian Air Force requirement for such an aircraft and that service currently has 15 on order as the MB-339CD.

The most significant changes to the MB-339FD are its modern avionics and cockpit displays. The MB-339FD’s cockpits are designed to be fully representative of next generation and modernised fighters, and each is fitted with three colour, active matrix, liquid crystal multi function displays. The three displays are identical and interchangeable. The MB-339FD has a head-up display in each cockpit and HOTAS (hands on throttle and stick) controls.

The MB-339FD’s avionics system is built on a dual redundant MIL STD 1553B databus. Main avionics components are the mission computer, ring laser gyro INS with embedded GPS, air data computer, stores management system, radar altimeter, a data recording system and a data transfer system. At the heart of the avionics system is the mission processor, its functions include main bus controller, system database, main computer, HUD symbology generator, MFD format selection, video signal manager, altitude alerter and vector map generation.

Mission data can be prepared on a ground based PC and downloaded via a cartridge into the data transfer system. Likewise recorded mission data, video of the HUD and inflight failure data can be retrieved from the data recording system for mission debriefing and analysis.

The MB-339FD is also offered with a number of other optional items. As on the MB-339C, a laser rangefinder for accurate weapons delivery can be fitted in the nose. Also as on the C, the FD can be fitted with a radar warning receiver mounted in the tail and chaff and flare dispensers (AN/ALE-40), and it can carry an underwing ELT-555 ECM jammer pod. The MB-339FD is also the first trainer to be offered with an inflight refuelling probe.

The MB-339FD’s six underwing hardpoints are designed to accommodate a full range of NATO and US standard weapons, including two 30mm DEFA gunpods, AIM-9 Sidewinder or Matra Magic air-to-air missiles, AGM-65 Maverick air-to-ground missiles, bombs, rockets and even two OTO Melara Marte Mk II anti ship missiles (launched visually or with target illumination from another aircraft or a pod mounted radar). Although the RAAF’s lead-in fighter requirement does not incorporate a close air support role, weapons training is important and any RAAF MB-339FDs would carry practice bombs and gunpods, etc. In addition the aircraft’s stores management system can simulate weapons delivery.

Airframe wise the MB-339FD remains largely as the MB-339C. Improvements to the airframe to extend life past the MB-339C’s demonstrated fatigue life of 10,000 hours include the use of some new materials in manufacture, new cold working manufacturing techniques and optimised weight distribution. It is also fitted with a strain counter system for expended life monitoring.

Power for the MB-339FD comes from a Rolls-Royce Viper 680-43, (which also powers the MB-339C) outputting a maximum of 4400lb (19.7kN). The powerplant is the major difference between the Italian Air Force’s MB-339CD and the FD, for commonality reasons the CD will be fitted with the earlier and less powerful Viper 632-43 of the MB-339A. The Viper turbojet is certainly proven, earlier variants powered the Jindivik, Jet Provost, Strikemaster and MB-326. The Viper 680 is the latest and most powerful incarnation and has a TBO of 1200 hours. Aermacchi claims that for a given mission, fuel consumption is “virtually the same” as that of similar performance turbofan powered trainers.

The MB-339FD’s fuel system holds 1430kg (3453lb) of fuel in three tanks, one two cell tank in the fuselage and the two wingtip tanks. A further 522kg (1151lb) can be carried by two underwing tanks. Endurance could be further extended by inflight refuelling.

To meet the Australian Industry Involvement requirements of the lead-in fighter project, Aermacchi has teamed with Hawker de Havilland and Honeywell Australia. If the Macchi is selected, Hawker de Havilland would assemble the aircraft at Bankstown, and would also manufacture some components and have responsibility for through life support. Honeywell would participate in electronic systems/avionics design, integration, production and logistics support.

The MB-339FD is likely to have the lowest unit cost of the three lead-in fighter contenders. Development of the advanced three screen glass cockpit is being funded by the Italian Air Force, while the rest of the aircraft is closely related to the MB-339C in service with New Zealand. Note optional inflight refuelling probe.

Deliveries of the first of 15 Italian Air Force MB-339CDs is scheduled for the second half of next year – one of the strengths of Aermacchi’s bid that development of the CD’s glass cockpit and other improvements (and hence risk) are being covered by the Italian Air Force. Deliveries are due for completion in 1997, meaning that Aermacchi would be well placed to meet the RAAF’s tight scheduling for a 1999 entry into service. Aermacchi says the other benefits of the MB-339FD for the RAAF’s requirement is the aircraft’s cost and overall compliance with the RFT.

The MB-339FD’s cockpit features three LCD multifunction displays, a head-up display and HOTAS controls. (Aermacchi)

Should the MB-339 be ordered there may be some scope for joint maintenance with New Zealand, given the similarity of engines and airframe between the MB-339FD and MB-339C, although commonality is somewhat limited given the FD’s new cockpit displays and avionics. The other MB-339 regional operator is Malaysia, although its aircraft are MB-339As with a less powerful Viper 632 and analog avionics, and any basis for maintenance cooperation would probably be limited.

The third contender for the LIF programme, the McDonnell Douglas T-45 Goshawk, will be reviewed in our March issue