After a 27-day hiatus, the first CSeries aircraft took off from Montreal’s Mirabel airport today for its fourth test flight.

The flight, which follows a second round of ground vibration testing, comes the evening before Bombardier is set to announce its third quarter financial results on 31 October.

The aircraft, a 110-seat CS100 variant, left Mirabel’s runway 24 at 15:36 local time and climbed northeast from the airport, reaching an altitude of 12,000ft, according to

The aircraft flew a back-and-forth pattern from east to west before turning southwest and descending back to Mirabel, where it landed shortly after 17:00 local, having completed a roughly 90min flight.

Bombardier did not immediately respond to a request from Flightglobal for more information about the flight.

The company flew the aircraft on its maiden flight on the morning of 16 September, following months of delays and build up.

After two more test flights, the last of which happened 3 October, Bombardier announced the aircraft would re-enter a series of ground vibration checks.

Those tests followed Bombardier’s June announcement that the aircraft had completed ground vibration testing, a necessary step in clearing it for its first flight.

The company has said the CSeries, which has Pratt & Whitney PW1500G geared turbofan engines, will be ready to enter service roughly 12 months after the first flight.

The aircraft was originally scheduled to enter service in late 2012, but Bombardier disclosed a six-month delay last November, which was attributed to the readiness of some suppliers. The milestone event was delayed further to 16 September,as Bombardier installed software updates and continued testing.

Source: Cirium Dashboard