BAE's Hawk is almost 30 years old. For how much longer can the advanced trainer's sales viability be maintained?

Next year, on 21 August, is the 30th anniversary of the first flight of the Hawker Siddeley Hawk advanced trainer. By then, BAE Systems hopes to have an order for 31 improved versions of the aircraft from its original customer, the UK Royal Air Force. If BAE and the Ministry of Defence can thrash out a deal, advanced Hawk 128s are due to be delivered to the RAF from 2006 - 30 years after the first Hawk T1 was delivered to the service.

BAE has subsequently sold over 800 of the two-seat jets (including the Boeing T-45 Goshawk for the US Navy) to 16 countries - more if users of the NATO Flying Training in Canada programme are added.

Since 1976, BAE has continually developed the aircraft. The RAF's T1 and the broadly similar Mk50 export versions were followed by the 60 series with the 5,700lb-thrust (25.4kN) Rolls-Royce Adour 861 turbofan and minor modifications to the wing and undercarriage. The subsequent Hawk 100 series has a new wing, with additional weapon pylons, including wingtip air-to-air missile rails. The cockpit has multifunction displays (MFD), a front cockpit head-up display (HUD) with repeater in the instructor's cockpit, hands-on-throttle-and-stick (HOTAS) inceptors and upgraded avionics, while a forward-looking infrared (FLIR) or laser designator can be installed in an extended nose.

Hawk 100s have been delivered with a variety of operational equipment, including in-flight refuelling probes and self-protection equipment. Other refinements include nosewheel steering and onboard oxygen generation. Marketed alongside the 100 series was the single-seat, radar-equipped Hawk 200.

Typically, each new customer has allowed BAE to develop the Hawk. The latest versions, the Mk127 lead-in fighter trainer (LIFT) for Australia and aircraft for South Africa, incorporate elements that will be the baseline for the RAF proposal.

The UK's future training plans are encompassed within its Military Flight Training System (MFTS), a proposed private finance initiative for aircrew training post-ab initio, through basic and advanced instruction to operational conversion unit (OCU) entry.

BAE made an unsolicited offer of the Hawk in 2001 and has been discussing it with the MoD. If new aircraft are to enter service in 2006, a deal needs to be struck this year. The RAF, however, is not BAE's sole target for the advanced Hawk, as it continues to seek exports, says Ray Rowlands, Hawk campaign support manager.

If BAE is to continue to sell Hawks, it has to develop an aircraft to compete successfully against the generation of trainers now in development, such as the Aermacchi M346, EADS Mako and Korea Aerospace Industries/Lockheed Martin T-50 Golden Eagle. These aircraft have capabilities that the Hawk lacks, such as fly-by-wire, a supersonic top speed and low-observable characteristics. Getting the new Hawk right for the export market is important and Hawk user group meetings have driven BAE's thinking, says Rowlands. The aircraft has been a significant earner for BAE over the past three decades and is the only aircraft in the company's portfolio that has export potential without the encumbrance of overseas partners. BAE predicts it can sell 400-500 new Hawks over the next 15 years.

Training needs are changing, says Hawk test pilot Pete Wilson. Skills acquired during advanced training have shifted from flying ability to developing situational awareness - the skill to manage not only the cockpit, but to develop an understanding of what is happening in the rest of a formation and being able to manage a mission.

New developments

The Hawk 128 proposed to the RAF will be based on Australia's LIFT aircraft, combined with the Adour 951 selected for South Africa's Hawks. The new engine is digitally controlled, has a mean time between overhauls doubled to 4,000h and is rated at 6,500lb thrust. Since August last year, BAE has been flying the Hawk New Development Aircraft (HNDA) from its Warton site in north-west England. Rowlands describes HNDA as the "34th LIFT" - the last aircraft in the batch built for Australia. This aircraft will shortly go to South Africa for a nine-month trial programme.

Like the aircraft, the Adour is significantly different from the engines delivered to the RAF in the 1970s. The Adour 951 is built in modules and incorporates single-crystal turbine blades and other refinements. Thrust could be further increased, although this would require changes to the Hawk's wing, intakes and structure. Additional thrust would improve acceleration and time to height, says Wilson.

It has been decided that the next-generation Hawk will have an open-architecture avionics system, says Rowlands. Open architecture makes it easier to introduce new avionics and sensors, and simpler to upgrade existing equipment. The system becomes "plug and play", says Rowlands. The company has selected an architecture stores management computer from BAE Avionics at Brough in eastern England and has tested it against a rival system.

BAE is also considering radar and weapons simulation systems, including carriage of a RAIDS pod, which allows the flight data, and performance against other aircraft, to be recorded for use during ground debriefing. RAIDS pods "are almost definite", says Rowlands.

Other considerations include the cockpit ergonomics and man-machine interface, adds Rowlands. The Hawk already has colour liquid-crystal MFDs and HUD. Mechanical standby instruments will now be replaced by digital displays. Other new cockpit avionics could include direct voice input, Terprom terrain-avoidance/following, helmet-mounted sights and a 3-5µm FLIR. Such additions will be customer led, says Rowlands.

Frontline emulation

Wilson says the Hawk cockpit, with its three MFDs, reflects a typical fourth-generation fighter, and tailoring the design for a customer allows the teaching of a frontline type's modus operandi. Hawk weapons and navigation systems can be adapted to operate like those in an air force's frontline type. Australia's Hawks mimic the Boeing F/A-18 Hornet. If a piece of information appears in the F/A-18's HUD, "we show it in the Hawk's HUD. We're making sure the pilot looks in the right place and presses the right buttons, to make it natural," says Wilson.

BAE has also considered introduction of a fly-by-wire flight control system (FCS) and performed aerodynamic studies. Hawk competitors often point to its lack of a digital FCS, subsonic performance and limited high-alpha performance. Rowlands says: "Do we look at fly-by-wire? Yes. But it doesn't come up as a prime objective from potential customers." He adds that the crucial question is "what value is fly-by-wire, what does it take from the OCU syllabus?" Transferring content from the OCU to advanced training provides a cost benefit; it is cheaper (or should be) to operate an advanced trainer than a frontline fighter. Fly-by-wire is an expensive option, notes Wilson, adding: "It's still in the melting pot, but I don't think it adds value, although we could do it for a customer."

Rowlands talks of performing "a half-way measure" to fly-by-wire. Addition of an autopilot would allow the aircraft to fly itself - as a fighter would, while the student concentrates on formation management and battle planning. Retention of a non-digital FCS will continue to provide a student with an aircraft that has to be flown correctly. "It teaches the student the reversionary procedures for when the digital systems aren't working," says Wilson.

During advanced training an air force is still trying to determine who will "make the grade", says Wilson. If a pilot during advanced training "can demonstrate three-dimensional situation awareness, then they will 'hack' high alpha [AoA] manoeuvres", he adds. In a typical 100h advanced training syllabus, high alpha would probably only be 1h, "then it is not worth the investment", says Wilson. Supersonic flight is the same, he adds. Once there was an issue with trim changes as the aircraft approached and passed through Mach 1, but not any more. "It takes money to make an aircraft supersonic," he adds.

Wilson believes the Hawk "is fast enough" for today's training requirements. The aircraft will fly at 540kt (1,000km/h) at low level, he says. "It does not accelerate the same as a frontline jet, but it stays there, and because of the engine's fuel efficiency it will stay there for a long time," he says. The Hawk can perform a 450kt initial point to target run like a frontline fighter, it can turn at 4g or 6g, similar to a combat aircraft, and fly a typical 1h low-level mission, he adds. He adds that not every frontline fighter is supersonic or capable of high alpha manoeuvring.

Wilson says the increased use of synthetic environments to teach repetitive drills and actions before a sortie is flown makes it possible to shift large formation training from the OCU to advanced training. Typically, pilots do not fly four-ship formations until OCU, but this could be moved to the training school, allowing pilots to train in "four versus four and eight versus eight" scenarios earlier in their careers.

Customer changes

BAE has considered improving the aircraft's aerodynamics, including the wing and intakes, and, while no decisions have been taken, Rowlands says "rather than be technically driven, we will only make changes to meet customer requirements".

If the Hawk is to remain successful, BAE needs to ensure that it only makes desired changes, says Rowlands. It also needs to avoid ending up with a significantly new platform. Support requirements and through-life costs are now understood, and systems issues have been addressed, but this knowledge would be worthless with a new aircraft, he says, although it is a key advantage in marketing the existing aircraft.

Source: Flight International