"Every milestone builds more confidence," says Rob Dewar, vice-president and general manager of the CSeries program.
"If you look at other programs, this is typically where people have challenges either on the wing testing or on the power-up so we're pretty comfortable. There's still a lot to do but getting these milestones behind us definitely builds confidence for the teams."
The Montreal-based aircraft manufacturer said the electrical systems were successfully powered on from a cable on the ground around 2 a.m. on Saturday, a week later than analysts had forecast.
The test plane contains more than 200 kilometres of electrical wires.
"We have already powered up some of the subsystems and we will progress basically through all of the subsystems in the coming weeks," Dewar said in an interview from Mirabel, north of Montreal, where most of the testing is taking place.
The electrical system has previously been tested at supplier Hamilton-Sundstrand and on the on-ground test plane, Dewar noted.
"We had very few snags, less than a handful (which is) better than expected."
Bombardier (TSX:BBD.B) also said Monday it has completed two crucial wing tests on its grounded test aircraft ahead of the plane's first flight, expected by the end of June.
It completed up and down bend testing of the aircraft's wings in March that applied intense pressure on the Belfast-made wings that simulated the maximum load the wings could face.
That testing performed was "clean" with no issues surfacing, Dewar said.
The company said safety-of-flight tests are progressing well on the integrated systems test rig for the 100- to 160-seat aircraft.
After finishing the first test flight aircraft, the CSeries will undergo ground vibration tests and then ground runs where the plane is taxied around its centre near the old Mirabel airport.
Bombardier won't say when that could take place or the window for when the first flight could occur.
"Our commitment has been to fly by the end of June and we're tracking to that plan."
Bombardier has received orders and commitments for 382 CSeries aircraft, including 148 firm orders. It expects to have 300 firm orders from 20 to 30 customers by the aircraft's entry-into-service in mid-2014.
Bombardier Aerospace president Guy Hachey told an investors conference last week that the CSeries is in a "critical execution phase" over the next six to eight weeks as systems integration is ongoing and being tested.
Among the main concerns is the navigation system, which needs safety approval before the plane can get off the ground.
Several analysts said they remain confident about the June target for the crucial test flight despite the risks.
"Given the additional transparency and significant progress in the last few months, we remain confident that first flight can occur by the end of June," wrote Benoit Poirier of Desjardins Capital Markets.
After first flight, Bombardier expects to add one plane in testing a month.
The Quebec company expects to produce 20 to 30 aircraft in the first year, ramping up to 120 per year in three to four years.
Poirier expects eight deliveries this year.
On the Toronto Stock Exchange, Bombardier's shares closed down 11 cents, or 2.71 per cent, to C$3.95 in Monday trading.