The plane could be seen in the 50ft-wide River Derwent, near the village of Aughton this morning, with just part of its tail sticking out above the water.
Two people managed to free themselves from the stricken craft after it came down at the weekend, They were taken to hospital but were not believed to have been seriously hurt.
A spokesman for Humberside Fire Service said crews were called to the remote spot at about 4.15pm on Saturday.
He said the two people on board did not need rescuing as they had got out themselves.
The spokesman said an air ambulance landed to take them to hospital.
He also said the Environment Agency was alerted due to the plane being in the river.
The aircraft is understood to have taken off from from Sherburn Aero Club, which is about eight miles away.
Club director Richard Maxted said he had "absolutely no idea what happened" to the two-seater Robin 2160.
He said: "An aeroplane inverted in the water is not something you see
every day, thank God, and at this stage we can't even specify what has happened."