TORONTO, March 18 (Reuters) – Air Canada has asked the government’s labor relations board to intervene after an unusually large number of pilots called in sick on a busy spring-break weekend, contributing to numerous flight cancellations, Canada’s largest airline said on Sunday.

Spokesman Peter Fitzgerald said the airline experienced “numerous delays and cancellations” over the weekend.

“While weather, a disruption caused by a fire at our major hub in Toronto, and other factors affected our operation, some impact was the result of a higher-than usual pilot book-offs,” he said by email.

“While Air Canada supports the right of its employees to book off when they are unwell or otherwise unfit to work, we cannot condone such activities as part of industrial action to disrupt our operations and we have asked the CIRB (Canadian Industrial Relations Board) to intervene.”

The airline did not specify what action it was seeking from the board.

Air Canada has been in dispute with several of its unions, including its pilots, as it seeks to cut costs and change the way it operates.

Arguing an Air Canada work stoppage could damage the economy’s fragile recovery from recession, the government intervened last week to prevent both a lockout of the pilots by Air Canada and a planned strike by the airline’s machinists.