Canada is in the midst of upgrading 14 its CP-140 maritime patrol aircraft with structural refurbishing (as needed) and new electronics. Canada has eighteen CP-140 Auroras, which entered service in the early 1980s. The CP-140 Aurora is an American P-3 airframe equipped with gear from the American P-3C Orion and the S-3A Viking naval surveillance aircraft. The CP-140 is mainly an ASW (anti-submarine warfare) aircraft that can also perform maritime surveillance, counter-drug, search and search-and-rescue. Three CP-140s were bought in the 1990s (the Arcturus model) for use as training or maritime patrol (no ASW) missions.
The refurbishment is mainly concerned with keeping the aircraft flyable for another twelve years, as well as and making them more capable when patrolling over land, there being much less of a submarine threat (with the demise of the Soviet Union submarine fleet in the 1990s) these days. Back in 2011, noting the success American P-3 and British Nimrod maritime patrol aircraft had at doing reconnaissance over land, Canada upgraded ten of its CP-140s so they could track things on land. Thus modified, the CP-140s were able to also serve on peacekeeping missions, where large, unruly areas have to be patrolled. This upgrade program has been proceeding, on and off (depending on which way the political winds were blowing) since the late 1990s.
Canada has the longest coastline (243,792 kilometers) of any nation on the planet. This is largely because of its immense (162,000 kilometers) Arctic coastline and the coastlines of over 52,000 islands. Eighteen CP-140s are not sufficient to constantly patrol these coastlines, but these aircraft can quickly be sent to any part of the coast if surveillance is needed.