Bombardier Reassessing CSeries Flight-Test Schedule

By Graham Warwick
Source: Aviation Week & Space Technology

Firm orders still stand at 177 aircraft, but will “definitely” reach the target of 300 by EIS, says Mike Arcamone, president of Bombardier Commercial Aircraft. Several customers are waiting for flight tests to confirm the performance projections, he says. Aircraft Nos. 2 and 4 are the performance-test vehicles. “Midway through flight test, will we have the majority of the performance data,” says Dewar.

The CSeries conducted its first flight in middle-of-the-envelope conditions, taking off at mid-weight and reduced thrust—which contributed to its extraordinary quietness. The aircraft reached 12,500-ft. altitude and 230-kt. airspeed, retracting the landing gear and varying flap and slat settings during a 2.5-hr. flight, says chief test pilot Chuck Ellis, who commanded flight-test vehicle 1 (FTV1).

There was one minor fault during the flight: an advisory message from one of the subsystems. “We made a small adjustment, and achieved all of our objectives,” Ellis says. Most of the extra time on the ground over the past weeks was spent testing and maturing the aircraft software. “A lot of the maturity work was around erroneous messages. We had one message on the flight, and there was no functionality issue. I was expecting five to 10, not just one,” says Dewar.

The CSeries is Bombardier's first fly-by-wire (FBW) aircraft, and FTV1's first flight was in the direct, or degraded mode that is the backup in the event of a flight-control failure. “We were very conservative, and by flying in a degraded mode were able to see the aircraft responding, not the FBW computers interacting. We were trying to remove that part of the equation,” Ellis says.

The FBW system will be switched to fully augmented normal mode for later flights. Bombardier's fly-by-wire control philosophy is “to give the pilots cues when the aircraft is approaching its limits, but allow them a bit more,” says Ellis. The CSeries also is the company's first aircraft with sidestick controllers. “We have soft and hard stops. But the aircraft is designed around the soft stops.”

The remaining four CS100 flight-test vehicles, the first production aircraft and the first test aircraft for the 130-/160-seat CS300 are in final assembly at Mirabel, but Bombardier will review the results from FTV1 before flying the next aircraft, in case changes are required. Modifications from ground testing have been rolled into FTV2-5. “Everything we learned on 1 we have put into 2-5. We could get two aircraft up fast, but there is no sense putting two in the air if we have to change them,” Dewar says.

Static structural testing has continued beyond the seven safety-of-flight cases required for first flight, with no issues so far with the aluminum-lithium fuselage and resin-transfer molded carbon-fiber wing. “We are tracking to plan,” says Dewar. Final assembly of the fatigue-test article has begun on site at IABG in Germany, where durability testing is expected to begin by year-end.

Test and initial production aircraft are being assembled at Mirabel, in a facility originally built for the smaller CRJ700 series. Construction of a dedicated CSeries assembly building will be completed by mid-2014, when production needs to move. The new building will have four fixed stations for joining of the fuselage sections and wing and mounting of the gear. Once on their wheels, aircraft join a moving assembly line for completion.

Production is beginning to ramp up, and is planned to reach a capacity of 120 aircraft a year by the end of 2016. China's Shenyang Aircraft, which already builds the rear fuselage section, is beginning assembly of the center and forward fuselage sections and will take over from Bombardier's Belfast, Northern Ireland, plant.

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