THE THREE KEY TARGETS for the Pilatus PC-21 development programme were that:

• the aircraft should have an aerodynamic performance capable of undertaking a wider training role than any other turboprop in the world;
• the training system should be the most capable and flexible in the world;
• acquisition and life-cycle costs should not exceed the turboprop benchmark.

On 1 May 2002, Pilatus Aircraft Limited rolled out the latest in a long line of turboprop training aircraft. PC-21 was an all-new design that began as a proof-of-concept study in 1998 and launched as a full-scale development in January 1999. The thrust of the programme was to produce an integrated training system that included a completely new aircraft and an associated synthetic training environment.

The aircraft that rolled out was loaded with an operational flight plan that included full engine, instrument and crew alerting system and a full training load from basic to simulated weapons for fighter lead-in training. The roll-out briefing demonstrated that the aircraft software load could be transferred into ground-based training and powered from a laptop. What the 300 guests could not see was that the aircraft was flightworthy. Less than 50 working days later, PC-21 had completed ground tests and satisfied the Swiss Federal Office of Civil Aviation that its airborne performance would meet safety requirements for a low-altitude transit across France to the Royal International Air Tattoo and the Farnborough Air Show.

The first prototype set off for a fault-free transit to RAF Fairford with just 10 hours 13 minutes' flight test time. Rapid prototyping using state-of-the-art design techniques that produce reliable and predictable results, save time, eliminate numerous prototypes and minimize development overheads that would be amortised and passed to the customer.

The Pilatus interpretation of an expanded envelope is to push capability and economic boundaries. Capability comes from aerodynamic performance and the ability of the avionics-based training system to teach pilots skills they will use on the front-line. Economics come from downloading this skill training from jet trainers that operate at cost ratios of 5:1 against the turboprop. The aircraft should challenge students by a calculated margin that stretches rather than frightens. This is done by mapping engine power as a function of airspeed and producing roll rates that are benign at moderate stick deflections and fighter-like when flown hard. Low-level speed range also is important and PC-21 enables navigational exercises to be flown at 300kts, unlike any other turboprop trainer.

PC-21 eats into jet time with significant economic benefits. Capability also comes from the ability to train pilots to manage complex avionics systems. PC-21 has three open architecture computers that power large active matrix displays, HUD and associated input devices. The cockpit is designed to maximise training value and be easily updated to cope with training requirements over its 30-year life. Changing a processor without a major software re-write and changing a display format without costly re-certification are essential to whole-life cost management that is also about relationships with suppliers. Contracts that address long-term service provision are likely to result in better value for money because they provide incentives for innovation and efficiency.

Expanded Envelope is not just about the platform capabilities. It is about the balance of capability, acquisition and whole-life cost. Development costs do have an impact on the platform price, easy updating reduces the life-cycle cost of ownership but innovative relationships with suppliers and downloading of training have significant effects on value for money. As for financial transacting options, such as PFI, Pilatus prepared for that in the development programme.