Three-quarters of Challenger jet fleet overdue for retirement

Four of Canada's six Challenger jets have reached the end of their service life, but National Defence has yet to retire them or develop a plan to replace them.

An analysis conducted for military commanders says the jets, which have been political lightning rods in the past, can no longer be upgraded and would cost additional money to remain in the air past 2014.

The 2013 documents, obtained by The Canadian Press under the Access to Information Act, laid out three different proposals, all of which called for the bulk of the fleet to be retired last year.

Jets safe to fly: government

But a spokeswoman for the Royal Canadian Air Force says all six of the Challengers remain in service with 412 Squadron in Ottawa and no changes have been made to their status.

Captain Holly-Anne Brown would not say when a decision would be made, saying the jets are well-maintained and safe to fly.

Options being considered include upgrading the on-board electronics of the 30-year-old aircraft in order to allow them to fly overseas.