Cyclone on 1st deployment since fatal crash grounded, 'temporarily unserviceable'

The CH-148 Cyclone helicopter accompanying HMCS Toronto on its latest NATO mission is "temporarily unserviceable for maintenance reasons," the Department of National Defence said Tuesday.

The deployment of the maritime helicopter was considered an important step forward in returning the aircraft to service after last spring's deadly crash off Greece, which claimed the lives of six military members.

"The current problem relates to the aircraft's fuel bladders, and is believed to be unrelated to any known issues," defence spokeswoman Jessica Lamirande said in an email CBC News.

"The issue is being worked on by our maintenance and technical experts along with Sikorsky, in accordance with the In-Service Support Contract."

The department gave no indication when the maritime helicopter would return to service.

HMCS Toronto departed Halifax on Saturday for a six-month mission.

Flight restrictions after April crash

The cause of the accident in the Ionian Sea, on April 29, is still under investigation, although the focus is on the flight control system and how the aircrew responded to unexpected actions by the computer system.

The director of the air force's technical airworthiness authority said last month that it's too early to say if there is something actually wrong with the flight control system.

The Cyclones were grounded in the aftermath of the crash but now that investigators have a handle on the cause, the fleet has been cleared to resume operations.

The downed helicopter had been flying off HMCS Fredericton in support of NATO's Operation Reassurance in the Mediterranean Sea.

The Halifax-based frigate returned to home port on Tuesday, where the crew was greeted by family members and Defence Minister Harjit Sajjan.

The crash killed Sub-Lt. Abbigail Cowbrough, Capt. Brenden Ian MacDonald, Capt. Kevin Hagen, Capt. Maxime Miron-Morin, Sub-Lt. Matthew Pyke, and Master Cpl. Matthew Cousins.

The setback for the new helicopter detachment comes as aircrews adjust to some of the flight restrictions placed on them as a result of the crash.

At the same time, HMCS Toronto experienced its own technical issues which delayed the warship's departure last week.

Lamirande said the frigate experienced problems with its port shaft bearing.

"Technicians were able to replace the part, however the time to complete the repair resulted in a two-day delay in departure," she said.

HMCS Toronto also experienced a "minor" internal fuel spill the night before its rescheduled departure.

"The spill was confined to the ship, but had to be cleaned up before the ship could get underway," Lamirande said.