Air North has confirmed it will drastically cut back its service between Whitehorse, Yellowknife, and Ottawa.
In a statement on Monday, the airline said the route will not be cancelled entirely but will instead be dropped between January and June 2019, then return for the summer period.
Existing scheduled flights up to and including January will continue to operate. The fate of the route beyond September 2019 is unclear.
"After much consideration, Air North has decided to reduce the frequency of regularly scheduled service between Whitehorse/Yellowknife/Ottawa during certain non-peak travel periods," read Monday's statement.
"Following the existing January 2019 flights, the route will resume for summer service starting 15 June, 2019 until 01 September, 2019.
"Additional flights may be added outside of our current schedule to support travel both to and from the Yellowknife and Ottawa regions."
Joe Sparling, the company's president and chief executive, said "rising costs" were the primary factor – in particular the cost of fuel.
Sparling had earlier criticized Yellowknife Airport for increasing its landing fees and imposing an airport improvement fee on passengers, suggesting those changes had also contributed to the decreasing popularity of the route.
Yellowknife residents had campaigned online to keep the route – which is currently twice-weekly – flying after first hearing of Air North's concerns about its long-term viability.
"Starting in early January, after the Christmas and New Year period, we will reduce our capacity during periods when our loads are likely to be very poor," said Sparling.
"By doing this, we will avoid operating flights which are not likely to meet their direct operating costs.
"This will allow us to continue to provide affordable service during high-demand periods."