OTTAWA -- The Liberal government said Tuesday it wants to buy 18 Super Hornets on a temporary basis until a competition can be held to replace Canada's existing fleet of CF-18 fighter jets. The decision-point comes after a drawn-out process to acquire new warplanes that dates back almost 20 years. Here's a timeline:

1980: Canada decides to buy 138 F-18 Hornets to replace existing air force planes. Their projected lifespan was about 20 years.

1997: The Liberal government invests $10 million in the U.S.-led Joint Strike Fighter program to develop a new fighter jet.

2000: Upgrades to the existing fleet of CF-18s begin in order to keep them flying until 2020.

2001: Lockheed Martin's F-35 wins a competition under the Joint Strike Fighter program, beating out Boeing.

2010: The Conservative government announces it will buy 65 F-35s to replace the CF-18s at a cost of $9 billion. The cost estimate and decision to sole source generate controversies for more than two years.

2012:

  • Auditor general releases report saying the price tag is $10 billion higher. Conservatives put a freeze on the budget, and hand the procurement process over to a new secretariat.
  • A separate Defence Department review later in the year pegs the full cost of owning and operating 65 F-35s through the 2050s at nearly $46 billion.
  • National Fighter Procurement Secretariat awards contract to KPMG to review financials for the fighter jet replacement program.
  • The secretariat begins consulting industry on available options to replace the CF-18.
  • Defence Department does its own assessment of the F-35.
  • Independent panel also appointed to review fighter jet options.

2014:

  • Independent panel delivers its report to government. It evaluated several plans but makes no recommendation, a decision left to senior bureaucrats.
  • The recommendation to cabinet is that the F-35 is the right choice.
  • The Conservative government says it will continue to participate in the Joint Strike Fighter Program to keep all options open until a decision is made on the replacement of the CF-18 fleet.

2015:

  • The Liberal promise in their campaign platform that they won't buy the F-35s and will hold an open and transparent competition. After forming government in November 2015, the mandate letter for Defence Minister Sajjan repeats promise to hold a competition, but drops specific language on F-35s.

2016:

  • Air Force commander Lt.-Gen. Michael Hood tells a Commons committee that Canada has enough fighter jets, and a decision on a replacement can wait five years.
  • Defence Minister Harjit Sajjan says the Air Force is facing a "capability gap," which he later explains as a shortage of fighter jets to meet its NATO and NORAD commitments.
  • Postmedia reports the government is looking at scrapping the idea of an open competition in favour of a sole-source purchase of Boeing Super Hornets. The government says no decision has been made.
  • Sajjan announces a new round of consultations with industry to decide the best path forward.
  • Canada pays $33 million to stay in the F-35 program.
  • The Liberal government announces it will enter negotiations with U.S. company Boeing to buy 18 Super Hornets as a stop-gap to make sure the air force has enough fighter jets until a replacement for Canada's CF-18s can be chosen in about five years. Costs are not disclosed.