Bombardier’s first CS300 has joined a CSeries test program now racking up flights at a rate the manufacturer says keeps the all-new airliner on track for certification toward the end of this year. Certification of the 135-seat CS300 is expected about six months after approval of the initial 110-seat CS100.

In addition to unique testing required for the stretched variant, two CS300 test aircraft will conduct trials to support certification of the basic design, augmenting flying by five test CS100s and the first production aircraft, which will be used for final FAA function and reliability testing.

The first CS300, flight test vehicle (FTV) 7, made a 4-hr., 58-min. maiden flight from Mirabel, Quebec, on Feb. 27. The aircraft and systems performed as expected, and with no post-flight modifications required, according to Bombardier, the aircraft was back in the air on March 3.

Maintaining a fast pace in flight tests is critical to meeting Bombardier’s commitment to begin CS100 deliveries this year after the 100-day grounding that followed the May 2014 uncontained failure of a Pratt & Whitney PW1500G geared turbofan during post-maintenance ground testing.

Testing has passed the 1,000-flight mark and “we’ve flown 25 hr. already in March, and that’s excluding the CS300,” Rob Dewar, Bombardier vice president and CSeries general manager, tells Aviation Week.

Initial results suggest Bombardier may be able to reduce the flight testing required to certify the CS300 because of its similarity to the CS100. “We chose to start tests with the longest flights we have so that if the results are favorable relative to the CS100, we can reduce a lot of testing,” he says.

“Handling on the first flight was absolutely identical to the 100,” Dewar notes, quoting pilot-in-command for the CS300 flight Andy Litavniks, who was co-pilot for the first CS100 flight in September 2013 and has a “couple of hundred hours” on the aircraft. “He did not see any differences, so we may have a smaller test program than we planned,” Dewar says.

Since initial results look good, Dewar plans “to put the 300s to work to help out the 100, as many of the systems are identical,” he says. “But we will keep the accounting separate, and those tests that are dedicated to the 100 will count against the 100’s certification target.”

Otherwise, the two test CS300s will focus on those aspects of the aircraft that are different from the CS100. “All the systems are identical part numbers except the brakes, fire extinguishers because of the longer cargo bays, and longer wiring harnesses,” says Dewar. The CS300 is 12 ft. longer than the CS100. “The only systems tests required are related to the differences.”

They will include cabin temperature pull-down/pull-up and smoke evacuation tests. The second CS300 test aircraft, FTV8, will be equipped with an interior. “We originally planned passenger evacuation tests but, based on the CS100 tests, we don’t think they will be required,” he says.

Taking advantage of the work already completed on the CS100, the CS300 entered flight testing in the latest build standard. “We have six build standards, mostly related to software, and FTV7 flew in Build 5, which is [entry-into-service] EIS-ready,” says Dewar, adding the final Build 6 will incorporate any changes that emerge from the remaining tests. One of the CS100s, FTV3, is also at Build 5, along with the first production CSeries, P1, which is off the assembly line in Mirabel and scheduled to fly this summer.

CS300 flight testing has begun with the fly-by-wire flight control system in back-up direct mode, without envelope protection, but will switch to normal mode shortly, says Dewar, adding that CS100 test aircraft always fly in normal mode. “First, we have to go to the more extreme parts of the flight envelope in direct mode, then we can move into normal mode.”

While FTV1, 3 and 4 were relocated to Wichita to take advantage of better winter weather, the two test CS300s are planned to remain in Mirabel. “We are over the worst of the weather and plan on keeping them here,” he says. The final CS100 test aircraft, FTV5, is scheduled to fly this month and will be based at Mirabel. FTV5 is the first CSeries to be equipped with an interior.

As for the CS100, “80% of high-risk tests are completed,” says Dewar. “We have finished all stall tests, with and without ice shapes, and meet all stall performance requirements. We have done engine relights—up to 24-26 per flight—with favorable results. We have done evacuation tests, all development tests for the brakes and preliminary noise measurements.”

Still ahead is runway performance testing, to confirm minimum unstick speed, which is planned for the spring in Salina, Kansas. Also to come is final certification of the brakes and runway water-ingestion testing. FTV2 has been configured for natural icing tests and Bombardier is waiting for the right conditions. “We are holding schedule. The best time is the fall or the spring, and the best conditions should be toward the end of March and into April. We are ready now,” he says.

Aircraft FTV4 has completed cruise performance testing, and results are “on track with or slightly better than” predictions, says Dewar. Test vehicles are usually heavier than production aircraft, but the CSeries FTVs “are in pretty good shape,” he notes, adding that “payload/range of the aircraft is better than brochure.”

Development tests to measure airport noise show the aircraft “is about 1 dB better than predicted,” he says. “Two measurement points are better and one is slightly worse, which is pretty good. We are quieter than the Q400.” Being as quiet as the Bombardier regional turboprop is critical to at least one CS100 customer, Porter Airlines, which operates out of Toronto’s downtown island airport.

With flight tests racking up, attention is turning to entry into service and Dewar holds daily meetings to track reliability and dispatch issues. “It is critical to identify and resolve these in flight test,” he says. “The test aircraft are averaging 98.5% dispatch reliability, which is a record for us in flight test.”

Ground tests and aircraft upgrades performed while the fleet was grounded last year have helped increase maturity. “The extra four months have helped,” admits Dewar. Malmo Aviation stepped down as the planned launch operator of the CS100 last year, citing the potential for further delays, but Bombardier is now “working with a couple of operators” on the pilot and maintenance training, manuals and spares provisioning required for service entry.

As for production, Dewar says the CSeries is now being built “in position,” as planned, with no traveled work. This includes the three aircraft on the final-assembly line in the new building at Mirabel: second CS300 test aircraft FTV8 and production CS100s P2 and P3. Fuselage work that was moved to Bombardier plants for the initial aircraft is now back in place with SACC in Shenyang, China, he says.

To stabilize the front end of production, Bombardier is building the first block of five production CSeries in a single configuration and the second block of five in a different “but very similar” configuration. However, Dewar says Bombardier has strived for a modular, track-mounted, “plug-and-play” interior configuration to avoid major customization. “All the customers so far are inside the box,” he says.

Bombardier in February revealed projected CSeries development costs now total $5.4 billion, up from the original $3.4 billion, in part because of last year’s grounding. Dewar says earned value—the credit accrued for hours flown—is slightly ahead of plan. But in the new development cost estimate, “we took a bit of margin—you can imagine there is not a big appetite to go back and ask for more money,” he says.

In the face of liquidity concerns caused by higher product development costs and lower free cash flow, the Canadian manufacturer in late February raised $868 million in new equity. This was more than 40% of the $600 million originally outlined under a new financing plan unveiled last month. Bombardier has also announced plans to raise $2.25 billion in new debt, up from the $1.5 billion outlined in early February. Citing the increased liquidity, and progress in CSeries flight testing, analysts have improved their outlook for the company. 

Editor's Note: This article was edited to clarify that the CSeries year-end goal is certification rather than entry into revenue service.