More time is needed to complete software verification

Full type certification of the Embraer 170 regional jet, expected this month, has been delayed until the first quarter of next year to allow more time to complete software verification for the Honeywell-developed fly-by-wire flight-control system.

The slippage means that deliveries will start more than a year later than the original December 2002 target set when the first aircraft flew in February last year. Since then the programme has suffered several slips, including a delay in the development of the aircraft's Honeywell Primus Epic avionics that pushed back full certification by three months to November from the revised target of June. The latest setback is unrelated to this.

Embraer received provisional type certification for the 170 from Brazilian airworthiness authority CTA on 13 November. While the manufacturer says this allows delivery of aircraft to airlines to begin crew training and route testing, Alitalia Express has opted to reschedule delivery of its aircraft to next year. Embraer says it is in discussions with US Airways aimed at defining initial deliveries of the 170. Because of the delay, the company has removed all eight 170s scheduled for delivery this year from its forecast, and is projecting deliveries of 102 aircraft for the year instead of the 110 previously announced.

Embraer says tests were completed with "good results in terms of performance, comfort and reliability", but that talks between the aircraft and avionics manufacturers, and the Brazilian, European and US airworthiness authorities, resulted in an understanding that additional flight-control system software certification documentation is needed before granting definitive type certification.

Honeywell says the flight-control software has been completely tested at the system level, and has performed to the certification requirements. The remaining work involves software verification tasks required for DO-178B certification. "Documentation is taking longer than expected," the company says. The complexity involved in certificating partitioned software in the Primus Epic integrated avionics was responsible for previous delays.

Source: Flight International