One of the Pratt & Whitney PW1500G turbofans installed on the first Bombardier CSeries flight-test vehicle suffered an unspecified “incident” late on Thursday afternoon during stationary ground maintenance testing at Bombardier’s facilities in Mirabel, Quebec, the airframe manufacturer confirmed on Friday.

Bombardier said it is investigating the incident with the support of Pratt & Whitney and the appropriate authorities, namely Transport Canada. “Safety is the priority, and the CSeries aircraft flight-test program will resume once the investigation is completed,” it said in a statement.

Contacted for comment by AIN, a Bombardier spokesman would not elaborate on the exact nature of the incident, but did acknowledge that it resulted in external damage to the engine and the airframe. He also noted that flight-test crew gained control of the situation soon after event and subsequently towed the aircraft into its hangar for more thorough inspection.

The spokesman added that the company did not expect the incident to result in another major disruption to the program.

Asked to elaborate on the nature of the episode, Pratt & Whitney issued a short statement acknowledging its participation in the investigation. “Pratt & Whitney is working closely with Bombardier to understand the incident,” it said. “No further details are available at this time.”