Air Canada is grounding its Boeing 737 Max 8 planes until at least July 1, as the investigation into the deadly Ethiopian Airlines crash continues.

The move comes as carriers work to fill the gaps left by the now-grounded aircraft.

The July timeline is intended to "provide customers certainty for booking and travel," the company said in a press release, and added there is no idea when the Max 8’s could return to service.

In the meantime, Air Canada has been substituting different aircraft on those routes, extending leases on planes scheduled to leave the fleet and even contracting and leasing aircraft from Air Transat for some flights.

Some routes have been temporarily cancelled, including seasonal flights from Vancouver to Kauai and the Big Island in Hawaii.

Air Canada says customers booked on those flights are being accommodated on other routings. Travellers affected by the changes will have a refund option and a full fee waiver, according to the company.

WestJet told CTV that beginning next week its flight schedule will reflect the grounding of Max 8’s through to the end of April.

"We are closely in contact with Boeing, Transport Canada and other regulators to understand how and when to safely reintroduce the MAX aircraft into service," said company spokesperson Lauren Stewart in an emailed statement.

Travel agency Flight Centre said a lot of its clients have been impacted.

"The thing to remember is it doesn’t just affect people that are booked on the aircraft, the Max aircraft," said vice-president of corporate communications Allison Wallace. "It could be that their travel plans are affected because of the reshuffling of planes. So, it’s really good to reconfirm your flight."

Wallace added people can check with their travel agent or the airline, depending on how they booked their flight, but warned it may be harder to get a concrete answer if your trip isn’t happening soon.

Air Canada has said it will be notifying customers of any changes. The airline has 24 of the 737 Max 8’s in its fleet, and was due to receive six more aircraft from Boeing in March and April. Those deliveries are currently suspended.