Embraer is conducting final validation tests of the fly-by-wire system on its new Legacy 500 midsize business jet, and is hoping to finally obtain clearance for the aircraft’s first flight within weeks.

Software issues with the fly-by-wire system have pushed back first flight by almost a year. But the system is fully installed, and executives are optimistic that those issues are well behind them.

Once it resolved the fly-by-wire issues, Embraer had hoped to have the first prototype flying by the end of September—but that schedule has slipped. The company’s conservative estimate is that the first flight will come this quarter, but executives are hoping that it could be within weeks.

Four Prototypes

While awaiting the beginning of the certification program, the Brazilian manufacturer continues to progress on development of the aircraft. Embraer displayed the first painted prototype to reporters Oct. 3 at its factory in Sao Jose dos Campos, Brazil. It is one of two prototypes that are ready to begin flying once the company receives clearance from aviation authorities. A third prototype, which will be used to validate interior systems, is in final assembly, and metal has been cut on the fourth Legacy 500, which will be used as a demonstrator.

The company has logged 2,500 hours on an iron bird test rig, used to test the fly-by-wire system.

The company is still targeting an entry-into-service date by the end of 2013, but Ernest Edwards, president of Embraer Executive Jets, concedes that could be an aggressive timetable, depending on when the aircraft flies.

As the aircraft approaches first flight, interest continues to pick up for the $18.4 million jet. Based on the current timeline, the next available Legacy 500 slot is at the end for the fourth quarter in 2015, Edwards says.

Aside from the fly-by-wire software issues, Edwards says the development program has been the smoothest that the company has ever undertaken. The aircraft is the first for Embraer to have a completely paperless design.

The digital design process involved three-dimensional simulations, not only for the aircraft itself, but for the development of the tooling and the development of the manufacturing processes. The company dedicated 800 engineers to the program.

Edwards notes that when Parker Aerospace encountered software problems with the fly-by-wire system, Embraer brought in its own engineers to team on the project. Parker also ended up subcontracting with BAE Systems, which helped work through the issues. Edwards, who says the issues were “just all a bad dream,” notes that the company has been pleased by the results from BAE.

The system is a complete fly-by-wire, a first for a midsize executive jet and the first complete system for an Embraer aircraft. It replaces conventional controls with electronic sensors that rely on inputs such as angle-of-attack, speed, temperature and aircraft configuration to control the elevator, aileron, spoiler and rudder.

The system provides automatic pitch, trim, roll and yaw compensation. It was designed with “soft limits” that enable the pilot to override normal performance envelope limits, but it corrects flight before the aircraft stalls.

The system is controlled by a side stick, replacing the traditional column. This provides a “cleaner cockpit,” says Augusto Salgado da Rocha, senior manager of product strategy and sales engineering for Executive Jets. In addition, Embraer is bringing auto-braking capabilities to one of its midsize aircraft for the first time.

Powered by two Honeywell HTF 7500E turbofans producing 6,500 lbst, the Legacy 500 will fly at Mach 0.82 with a 3,000 nm range. The cockpit is equipped with Rockwell Collins Pro Line Fusion avionics with four 15-in. displays that incorporate capabilities such as synthetic vision, electronic charts and graphical flight planning. Also offered is enhanced vision and head-up guidance capability.

While called a midsize, the cabin’s cross-section is more akin to a super midsize, with a 6-ft., stand-up cabin that is 6 ft., 10 in. wide. The aircraft can hold up to 12 passengers.

Support Network

While Embraer continues with the development program, it is establishing a support network that is expected to be announced soon, says Edson Carlos Mallaco, VP of customer support and services for Embraer Executive Jets.

The first simulator, provided through its partnership with FlightSafety International, is being built and should be ready for testing by year-end, Mallaco says. While Embraer has not determined the exact location for training yet, he expects the first simulator will be stationed in the U.S. and a second in Europe.

Once the aircraft moves into flight testing, Embraer expects to shift some engineers to the development of the smaller Legacy 450, which was launched alongside the 500 in 2008. Both models were designed with a goal of 95% commonality—the main differences being that the 450 has a shorter fuselage (it holds seven to nine passengers) and less range (2,300 nm). Both aircraft will share a type rating.

Embraer cut metal on the first 450 in August. The 450 development program is expected to benefit from work accomplished on its larger sibling and is expected to follow just a year behind the 500.