An aircraft per month, start end 2009

The engine will be Honeywell's F-124, digital flight control system is by Teleavio/Marconi Italiana in collaboration with BAE Systems of Santa Monica, and Dowty and Microtecnica for actuators. The avionics core system, including Head Up Displays, LCD Multi-Function Displays and the main Mission Processor, is provided by Alenia DSAE, and the Inertial Navigation System/Laser Gyro and integrated GPS by Honeywell. Ejection seats are Martin Baker/ SICAMB Mk 16. The electrical generator is provided by ASE (formerly Magneti Marelli Avio). Partnership agreements have been reached with Honeywell/FIAT Aviazione, Teleavio/Marconi Italiana/BAE Systems, Alenia DSAE and ASE. Further agreements are expected, also in the area of the Training System/ground based training media.

The first M-346 prototype is scheduled to fly by mid-2002, followed by a second prototype one year later. Full development funding is in place. The Italian Air Force will be in charge of certification. Deliveries are planned by 2005.-346 Gets Ready to Test the Market


Apr 22, 2007
By Andy Nativi

The moment of truth is near for AleniaAermacchi, as the company wraps up development work on the M-346 advanced jet trainer. There appears to be little doubt as to the aircraft's technical credentials, but offering a high-end trainer in a distinctly low-end budget environment will pose a formidable challenge.

The trainer aircraft business is a fickle one. Everyone needs them, though nobody wants to spend the money. Procurement decisions are delayed as scarce budgets are diverted to sexier projects. There's rarely a quick return on investment, taxing the patience of even the most steadfast chief financial officer.

And while margins in the high-end trainer business can be decent, the financial risks can be dire. It's that kind of an environment that caused EADS, for instance, to abandon its own plans to develop a product--the Mako--for this segment.

Clearly, it's not a business for the timid. Carmelo Cosentino, CEO of AleniaAermacchi, points out that "several companies are able to develop, from scratch, a new advanced trainer. But it is a long and costly exercise, requiring at least €1 billion ($1.35 billion) for a transonic aircraft and €1.5-2 billion if a supersonic design is pursued."

That the market isn't easy is evident. Even though the aircraft is maturing, AleniaAermacchi so far has failed to win a launch customer.

For the Italian company, seeing the M-346 through was a more natural decision than for others, because it is fundamentally a trainer house. It has produced as many as 2,000 trainers, selling the full range of such aircraft, from the basic SF-260s, offered as piston or turboprop-powered models, to the advanced jet-powered MB-339, now being reintroduced, to the still-in-development M-346.

So in a market where there are already plenty of offerings--the BAE Systems Hawk and the Korean Aerospace Industry T-50 to name two--what does the M-346 bring to the table?

Program officials say it is the first true fifth-generation trainer, but such nomenclature is often mere marketing spin. In this case, they mean it prepares students for the latest generation of front-line fighters and represents a modern-build standard. AleniaAermacchi representatives contend they've actually skipped a generation, since what is commonly referred to as fourth-generation trainers are nothing more than third-generation models with avionics upgrades.

The T-50 is generally seen as falling in the fifth-generation category, too, although it is conceived as an element of a "family" of aircraft that include the A-50 attack version and the potential F-50 light fighter. That has driven different design choices, emphasizing combat more than training, backers of the Italian aircraft argue. The market in the coming few years will indicate whether AleniaAermacchi's views are reflected by their customers.

The M-346 has had a long and sometimes rocky history. The project builds on work Aermacchi undertook in the 1980s to identify the requirements for a next-generation advanced trainer. These culminated in the early 1990s in the AT-2000/PTS-2000 study with what was then still part of Dornier. In parallel, Russia's Yakovlev performed similar studies.

That led in 1992 to Aermacchi and Yakovlev partnering, to share knowledge and develop the Yak/AEM-130D demonstrator. The latter started flying in April 1996. But differing project requirements, corporate priorities and Russia's financial crisis ended the cooperative effort in 1999.

As a result, despite a shared ancestry, the M-346 and Russia's latest trainer, the Yak-130, are fundamentally different.

The M-346 is much smaller and lighter, but with a wider flight envelope, more agility and a higher thrust-to-weight ratio. The Yak-130 was hurt by the cancellation of the Klimov RD-35 engine program, which forced Yakovlev to use the less-powerful, compact DV-2. With heavier electronics and systems, the aircraft lags compared with its sibling, although its price tag is much lower.

The Italian project moved into high gear in 2000. The first prototype was rolled out in June 2003 and started flying in July 2004, followed by a second aircraft in May 2005. The two prototypes have logged more than 300 flight hours, shared roughly equally. AleniaAermacchi plans to complete 700 flight hours before full operational capability is reached.

The test program has had its share of glitches. The flight control system didn't mature as quickly as hoped, so AleniaAermacchi shifted some work from its principal partner, BAE Systems, to sister company Alenia Aeronautica. The latter holds a licensing arrangement with BAE, but the shift cost time.

However, most aircraft changes have been relatively minor. The air brake initially was to extend 60 deg. but that resulted in tail buffeting, so the extension is now limited to 40 deg. The eventual fix is to move the brake 1-meter forward, while the intake for the environment control system, at the root of the tail, will be enlarged. It had been partially masked by the open speed-brake.

Control laws are still being refined and, so far, don't support the full airframe capability. In particular, it isn't easy to optimize use of the leading edge flaps to vary camber as a function of angle of attack, Mach and total pressure.

Other lessons could yet emerge as trials examine the most extreme points of the flight envelope, but developers are sanguine that they have no major worries.

The next M-346 to be delivered will be the first production representative model and is due to fly by year-end. It will be used to fully test, develop and then freeze the production configuration, and to certify the full structure.

The most immediate program milestone is a "development initial operational capability" standard. The Italian air force is set to certify the core systems and the fully expanded flight envelope. In 2008, a second certification for the production standard should take place, followed a year later by approval of the cleanly configured aircraft throughout the flight envelope. Finally, in 2010, the M-346 is scheduled to reach full operational capability, including seven basic armaments load-outs.

Production should take place in parallel. Output capacity will be for eight aircraft per year, but could grow to an aircraft per month should the market demand it. The low-rate build should be completed in 2010, with deliveries starting in late 2009.

Systems and aircraft performance are what truly define the M-346. Despite its bid for the high-end market, AleniaAermacchi steered clear of pushing to the extreme of the flight envelope, opting to forgo an afterburning engine, arguing that associated acquisition and operating costs rendered it nonviable. A high-transonic aircraft with two non-afterburning engines and greater agility will combine safety and low costs with performances equivalent, or even superior, to those offered by combat aircraft in a large part of the flight envelope (corner speed is at Mach 0.6/15,000 ft.), without sacrificing ease of control at takeoff, landing and approach, says PieroClaudio Iaia, M-346 program manager.

The M-346's aerodynamic configuration has been optimized for that performance. The aircraft's trapezoidal, mid-mounted, variable-camber-wing, with a leading edge sweep of 30.8 deg. and a moderate aspect ratio of 4, features a profile, with a 2% twist, and a thickness (6% at the tip, 8% at the root) specifically designed for transonic performance.

The flat, lower fuselage contributes lift (up to 30% of the total), and the wing is carefully blended with the fuselage, which includes generous leading edge extensions that are instrumental in aircraft controllability at high angles of attack (AOA), coupled with patented wing fences. The leading edge extension and fence combination allows the aircraft to exploit vortex lift, avoiding vortex bursting and the associated loss of lift.

Exploiting the vortex lift is particularly important for M-346 high-angle performance, since the aircraft doesn't have canards to help in that portion of the flight envelope. An added benefit is that the leading edge structural element shields the air intakes from ingesting unstable air that can lead to loss of thrust and further engine problems.

Thanks to a carefully calibrated ratio between the intake capture and throat areas, the high AOA/maneuvering intake pressure recovery is 0.97, maintaining good engine performance. With an optimal lift/drag curve over a wide part of the envelope and a lift coefficient maximum of 1.6, the aircraft is designed for short takeoff and landing runs, while both drag rise and trim drag are reduced and controlled over a large part of the envelope.

Designers placed particular attention on post-stall recovery and controllability at very high AOA. The M-346 is supposed to allow "carefree" handling and complete spin resistance well above 40-deg. AOA, a performance level that only some fighter aircraft can achieve. A raft of design factors contribute to the stability at those operating extremes, including the wing, wing fences, carefully rounded nose and a fuselage with a low-aspect-ratio forebody, a high tail positioned well forward on the fuselage spine to keep it effective at high AOA, and the generously sized horizontal tail to achieve the high-control authority.

The aerodynamic formula is bolstered by a four-channel reconfigurable digital flight control system, which manages a moderate subsonic relaxed longitudinal stability (5%) of the aircraft, that in turn allows maximum agility in the air combat arena. The level of redundancy allows the M-346 to continue its mission even if one channel fails. A dual-channel failure still allows degraded performance to return the aircraft to base. Instructors can deliberately degrade the flight controls in flight to teach students how to handle the aircraft in such situations.

The aircraft is powered by twin Honeywell F124-GA-200s, with dual-redundant full authority digital flight controls. The powerplants are designed to work with a sub-optimal airflow and be surge resistant, thanks to the high-pressure compressor design which features four axial stages and a centrifugal stage. Even though the bypass ratio is merely moderate, at 0.47, the specific fuel flow consumption is low. A production M-346 with 50% of fuel load, weighing about 5,900 kg. (13,007 lb.), will have a thrust-to-weight ratio of 0.9:1. By comparison, an advanced trainer with a single afterburning engine needs to use reheat to achieve maximum performance and a thrust-to-weight ratio nearing 1:1, and will therefore have merely one-third the endurance.

The engine also provides thrust growth possibilities. A near-term step would see improvements to the high-pressure turbine's material to a single crystal, which would deliver an extra 300 lb. of thrust. The long-term plans, says Mark Johnston, an engineer at Honeywell Aerospace, include shifting to an advanced, two-stage fan, which would increase both fan flow and efficiency and provide for an increase to 7,500 lb., about 1,000 lb. more thrust than now available.

On the avionics front, AleniaAermacchi has tried to find a low-cost way to replicate most of what would be found on a modern combat aircraft. The trainer is fitted with dual-redundant, 1553B digital data buses. It also carries two main computers, a navigation suite including a ring-laser gyro inertial navigation system with GPS radar altimeter, along with more traditional navigation beacon systems, a communication suite with friend-or-foe identification system, and two V/UHF radios (a third is on the prototypes). There are also dual head-up displays and the capability for helmet-mounted displays.

Like most trainer aircraft developers, AleniaAermacchi is keeping the option open for a combat aircraft derivative. The M-346 could carry up to 3.1 tons of external stores, distributed over nine wing and fuselage hardpoints. It could still achieve a 515-kt., 5.5g turning performance with a heavy load-out.

Although the trainer doesn't have a radar system, the nose section can be outfitted with a mechanical or electronically scanned array that would be provided by Galileo Avionica Grifo. Environmental control and power supply allow for the upgrade. Installing a navigation, laser-designation, or reconnaissance pod, with the ability to display imagery on the head-up displays or helmet-mounted sight should be possible. Provisions also exist for installation of electronic countermeasures.

While the aircraft is not intended to be stealthy, as AleniaAermacchi engineers will openly concede, steps have been taken to minimize the radar cross section. For instance, the engine's diverterless air intakes have slightly curved ducts in order to partially mask the engine compressor face in frontal aspect from an adversary's radar. The duct and lips can be covered with radar-absorbing material. Similar surface treatment would be applied to the wing's leading edge, in particular the obvious dogtooth, which otherwise would generate a significant radar return. Wing fences and pylons also would be covered.

The third prototype will sport a canopy with an advanced "gold" film, which will mask the double cockpit.

Provisions have also been made to boost survivability in the infrared arena. The relatively cool engines have a diffused jet plume thanks to the nozzle position, which has the dual benefit of reducing the infrared signature and drag.

Another derivation could be a single-seat version. The space now used by the back seat would allow for additional fuel or other equipment to be carried.

But the aircraft alone is only one element of any modern training system. Therefore, AleniaAermacchi is developing the broader training system concept, which would include the typical array of simulators, spanning from simple cockpit trainers to a full-motion arrangement. Partners, expected to be named soon, would be responsible for those efforts.

One of the system's features is an embedded simulation capability, used mainly for the most advanced phases of training. The system can replicate multimode fire-control and missile-warning radar receivers and countermeasures systems, including jammers, and the Link-16 Multifunction Information Distribution System that is becoming the backbone of coalition air-to-air combat tactics. Both air- and ground-threat scenarios can be played out.

The question now is whether these attributes will loosen tight wallets. AleniaAermacchi officials argue that use of the M-346 is more cost-effective than having the advanced phases of tactics and flight training done on actual combat fighters. They also note that many advanced fighters, notably the F-22 and F-35, will exist only as single-seaters. It's no surprise, then, that the company is courting the U.S. Air Force as a potential customer.

A slew of trainer aircraft decisions are expected in 5-10 years. But even before then, some important customers will indicate how the market is leaning. Greece, Poland, the United Arab Emirates and a few others are now in the market for an advanced training solution.

A handicap, however, is that the Italian air force has not yet bought the aircraft, although it has signaled an intent to do so. Company officials hope for confirmation soon. The Italian economic development ministry likely will finance part of the entire 12 low-rate aircraft, properly kicking off production.

AleniaAermacchi-parent Finmeccanica isn't just relying on the aircraft's attributes to do the sales job. Industrial workshares are being offered to companies in countries buying the aircraft. That card is already being played in Greece, where Hellenic Aerospace Industries has been made a partner.

Cosentino argues that "there is plenty of room to craft a cooperative program with involvement of partners in both the aircraft and the other elements of the complete training system."

M-346 SPECIFICATIONS

ENGINES
(2) Honeywell F-124-GA-200
THRUST, at sea level
28 kN (6,250 lb.)
INTERNAL FUEL
1,850 kg. (2,050 series)
MEASUREMENTS
Wingspan
9.7 meters
Length
11.52 meters
Height
4.98 meters
WEIGHTS
Empty
6,000 kg. (4,700 series)
Takeoff, clean
8,000 kg. (6,700 series)
Takeoff, maximum
8,000 kg. (9,800 series)
SPEED, max.
Mach 0.97 / 575 KCAS
(Mach 1.2 / 600 KCAS series)
LIMIT LOAD FACTORS
+7 / -2.5g (+8 / -3g series)
ANGLE OF ATTACK, max.
20 deg. (+40-deg. series)