Bombardier confirms that the fly-by-wire system on its first CSeries test aircraft has been set to “direct” mode during the first four test flights.

The aircraft has not yet flown with the fly-by-wire system set to “normal” mode, but the company will test more of the aircraft’s systems during subsequent test flights, Bombardier tells Flightglobal.

The latest test flight, on 30 October, was intended to calibrate the aircraft’s instruments and to ensure their accuracy, the company says.

During that 90min flight the aircraft climbed to 12,000ft and reached speeds up to 340kt, according to Bombardier.

The aircraft has flown four times since the first flight on 16 September, but the latest flight follows a 27-day hiatus in flight testing.

Bombardier said it conducted a second round of ground vibration tests during that period and installed a software update to the fly-by-wire flight control system.

The CSeries fly-by-wire system is operated in two modes: direct and normal.

Airline pilots are expected to fly the aircraft almost always in the normal mode. Flight envelope protections to prevent the aircraft from stalling or manoeuvring too aggressively are activated in this mode.

The direct mode provides none of the envelope protections offered by the fly-by-wire system and would only be used by airline pilots in degraded situations.

Source: Cirium Dashboard