Software problems in a remote electronics unit tied to the fly-by-wire control system for the new Embraer Legacy 500 and Legacy 450 business jets are at the root of a one-year delay in first flight and certification, the Brazilian airframer has revealed. Originally set for certification in the second half of 2012, the company now plans to certify the twinjets in late 2013 and 2014, respectively.

Embraer chief executive Frederico Curado, speaking to analysts during the company's third-quarter results call on 2 November, said certification had "never" been planned for 2012, although Embraer - as recently as August - had held to a 2012 certification for the Legacy 500, followed approximately one year later by its smaller sibling, the Legacy 450.

Set to fill the gap between the Phenom 300 light jet and Legacy 650 super-midsize, the Legacy 500 and Legacy 450 midsize and mid-light twinjets feature sidestick controllers and three-axis fly-by-wire control systems, built by US-headquartered Parker Aerospace and its subcontractor, aerospace defence and security giant BAE Systems.

US-based manufacturer Rockwell Collins is supplying its Pro Line Fusion integrated avionics suite for the cockpit.

An Embraer spokesman said the remote electronics unit software is Parker's responsibility, and Embraer continues to work with the company "to understand the full extent of the issue and its resolution".

He added: "The flight control computer and its software developed by BAE are ready to go. From what we have seen so far, the first flight delay is unlikely to go beyond the third quarter of next year.

"The prototypes continue to be assembled as planned and Embraer rearranged the ground test sequence, including ground vibration tests, fuel system, brakes and steering and maturity tests, to minimise impact on entry into service."

First flight of a pre-production Legacy 500, previously scheduled for some time in the third or fourth quarter of this year, has been pushed back to the second or third quarter next year, Embraer added.

Flightglobal first reported delays with first flight due to the fly-by-wire software issues at the National Business Aviation Association gathering in early October. At the show, Embraer reported that it had mated the wing and fuselage for the first of the three prototype aircraft and was installing various systems, as well as the vertical and horizontal stabilizers and cabin door, rudder and elevator assemblies.

The Honeywell HTF7500E engines for the first aircraft have also been delivered to Embraer's manufacturing facilities in Brazil.

"Our supplier we just found out is late," Curado said in the 2 November call, adding that Embraer was debating the issue and would likely bring the software "in house".

Source: Flight International