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.