Fighter manufacturers are eyeing an opportunity to replace the Swiss air force's entire fighter fleet, although the requirement will be the subject of a public vote planned for early 2020.

Four years ago, Switzerland's planned acquisition of 22 Saab Gripen Es was scrapped after a public referendum narrowly rejected the allocation of funds required to purchase the Swedish-built type. The deal had been intended to replace the Swiss air force's aged Northrop F-5 interceptors.

Last November Bern then outlined an ambitious "Air 2030" programme to replace its F-5s, Boeing F/A-18C/Ds and ground-based air-defence systems during the next decade, with the activity valued at Swfr8 billion ($8.4 billion). Proceeding with such a sweeping modernisation activity would require approvals to increase its current defence spending levels by 1.4% per year.

Outlining its latest programme schedule, the nation's government says parliamentary debate will occur in 2019, before a public referendum to be conducted no later than "spring 2020". Selection of a new fighter is likely to occur by the end of the same year, it adds, with a contract signature likely in 2022 and deliveries anticipated between 2025 and 2030.

The Swiss air force has an inventory of 53 F-5E/Fs, although only 26 of these are regularly flown – and only in daylight and good visibility. "Against an adversary equipped with modern means, they would have no chance," the government says. Bern also operates a 30-strong F/A-18 fleet, with the twin-engined model expected to remain in frontline use until 2030.

Potential candidates for the fighter fleet renewal include the trio of types considered in the last phase of Switzerland's previous contest: the Gripen E, plus Dassault's Rafale and the Eurofighter Typhoon. Boeing may also promote its F/A-18E/F Super Hornet, while Washington could pitch the Lockheed Martin F-35.

Among the terms of its procurement plan, the Swiss government will seek an offset package worth at least 100% of the purchase price.

Separately, the air force has performed inspections on its F/A-18 fleet, following the discovery of cracks in a landing flap hinge on a C-model fighter late in January. The activity identified a similar problem on a further five aircraft, the first of which was returned to use in early March following repairs performed by RUAG Aerospace.