Four people trapped when an ultra-light plane crashed and lodged in a ferris wheel have walked away uninjured.

The 53-year-old pilot and his 32-year-old male passenger were rescued from the wreckage nearly three hours after the plane crashed into the wheel at fair grounds in the seaside township of Old Bar, on the NSW mid-north coast, on Saturday morning.

The light aircraft lodged in the frame of the amusement ride more than 10 metres off the ground.

A nine-year-old boy and a 13-year-old girl who were on the ferris wheel at the time of the incident were trapped for more than an hour before being rescued.

"All the people involved in that incident do appear to have been able to get away without any serious injury," a Rural Fire Services spokesman said.

Local resident Gary Jones said his nine-year-old twin boys got off the ferris wheel just seconds before the plane hit.

"It was a hell of a shock," Mr Jones said today.

"My sons were on the ferris wheel ... they got off probably 60 seconds before (the plane hit)."

Emergency services are currently using a crane to extract the wreckage of the Cheetah S200 from the ferris wheel.

Air Safety investigators will examine the circumstances surrounding the crash.