The wreck of three aircraft downed during World War Two have been found off the coast of the Federated States of Micronesia.

Photo: University of Delaware

Researchers from NGO Project Recover and the universities of Delaware and California made the discovery.

It took the group four expeditions over the course of two years to find the crafts' remains.

Researchers spent 50 days surveying nearly 70km of seafloor before making the discovery on the sea floor in Chuuk State in the FSM.

According to the University of Delaware, the downed aircraft included two Dauntless dive bombers and one Avenger torpedo bomber.

It said the aircraft flew from the aircraft carriers USS Enterprise and USS Intrepid and went missing in action 76 years ago.

Photo: University of Delaware

The aircraft were also associated with seven American servicemen missing in action during the war.

The university's School of Marine Science director, Mark Moline, said while the discovery of those sites was exhilarating and validating, the feelings were mixed with the "humbling emotions of the sacrifices made by these service members and their families in protecting our freedoms".

Project Recover's lead archaeologist Andrew Pietruszka said researchers were "now assembling reports for review by the US government to potentially set into motion a process for recovering and identifying the remains of up to seven crew members".