Ahead of the 1936 season, the airport was equipped with permanent installations, including wharfs and a small terminal building.

However, DNL considered that the fjord was not sufficiently protected against the elements, had too large waves and too much ship traffic.

[3] The service had three weekly round-trip flights, with stops in Bergen, Ålesund, Molde, Kristiansund, Brønnøysund, Sandnessjøen, Bodø, Svolvær, Narvik, Harstad and Tromsø.

The port authority had considered the possibility of using Ilsvika on the fjord, but the site was exposed to waves and would need the expansion of a causeway.

These included a floating wharf, a slipway to avoid aircraft being damaged if they should blow on land and a terminal building.

[6] The plans were approved by the municipal council in February 1936, allowing construction of the 18,000-Norwegian krone project to commence.

Operation of the airport was carried out by the airline, which received a subsidy of NOK 1,400 from Trondheim Municipality.

[11] NFDS subcontracted the airport bus to Styrkaar Melbye, who held the concession to operate a scheduled service to Jonsvatnet.

[13] For the 1937 season the service was taken over by Widerøe, flew a route from Trondheim via Brønnøysund and Sandnessjøen to Bodø using a Bellanca 31-40.

The route commenced on 3 July and flew five round trips per week until the season was completed on 30 September.

This was in part because the government required increased municipal contribution to the routes, which were largely financed through state subsidies.

Contrary to their intelligence statements, Værnes was in a dilapidated state, lacking such amenities as a paved runway.

All supplies would need to be flown in to Trøndelag until 13 April, and it was therefore imperative for the Wehrmacht that an air base be established in the region.

[15] The Wehrmacht, therefore, decided the following day that it would use the iced up lake of Jonsvatnet as a temporary air station, located between Valset and Malmannøya.

[15] The ice was still thick on the lake, about one meter (three feet), giving sufficient support for the Luftwaffe to land heavy bombers at Jonsvatnet.

[17] British and French troops landed in the Namsos area on 14 April, causing an increase in German air activity.

Attacks also targeted Allied ships, and the bombers were successful at sinking Rutlandshire of the Royal Navy.

However, the ice was beginning to melt and the Luftwaffe determined to start evacuation of the airfield, moving the aircraft to Værnes.

A British reconnaissance mission on 25 April concluded that only two aircraft were left and that the airport was generally abandoned.

The Heinkel He 111 and Junkers Ju 88 aircraft were unable to take off and were, after their fuel tanks had been emptied, abandoned by the Luftwaffe and sank soon afterwards,[22] to a depth of 74 meters (243 ft).

[24] After the war ended, DNL resumed flights from Trondheim in 1946, this time using Ilsvika as its main airport.

[25] Vestlandske Luftfartsselskap started a seaplane service from Bergen via Ålesund, Molde and Kristiansund to Trondheim on 14 May 1951.

[26] The aviation club signed a lease for lakeside property at Valset in 1967, intending to relocate their operations from Værnes to Jonsvatnet.

The issue lay at rest until 1994, when Forsvarets Forum questioned whether the wrecks were a threat to the lake as a drinking water source.

The Norwegian Aviation Museum received permission from the Ministry of Defense in 1995 to raise the wrecks, as they never determined what to do with the aircraft.

However, there were contradictions in restrictions: domesticated cows were allowed to bathe, but not humans, and all motor boat activities were banned, although the lake acted as a water aerodrome.

During the public hearing, the Ministry of the Environment supported the municipality's stance, stating that the lake, as a recreational and nature area, should be shielded from use by seaplanes.

[36] Plans for raising the wrecks resumed in 2004, after the German Museum of Technology in Berlin offered to pay the cost of the work.

[30] The military invited Artur von Casimir, the Heinkel's last pilot, to witness the operation, which commenced on 24 August 2004.

[41] This time the CAA supported the motion of closure, citing reasons of general public interests.