The 62-year-old suffered serious leg, chest and head injuries and was taken to the Launceston General Hospital.

Police said that after a successful take-off in his single-seater Monnett, the pilot lost power and turned the aircraft before spiralling out of the sky about 5.35pm.

The plane plunged 100m, crashing into a paddock about 200m from Daveys Lane at Western Junction, 1km south-east of the airport.

Details on the man's proposed flight path were not available last night.

Western Junction couple Rick and Trudy Hart were working outside in their vegetable garden in Trafalgar Lane when they heard what they described as a "very loud lawn mower".

"It was a terrible noise and then it just cut out and dropped," Mr Hart said.

"We heard the engine stop. We drove around the corner, saw him try to turn. He did a few ugly loops and disappeared behind the trees.

"When we heard the thud we knew he was in trouble and rang triple zero."

Mr and Mrs Hart witnessed emergency crews pull the man from the wreckage.

"It is a miracle he is alive, all you have to do is look at that," Mr Hart said.

"But he was talking."

Emergency services were notified of the incident at 5.40pm.

Launceston police Sgt Jayson Taws said the Bureau of Air Safety Investigation had been advised of the accident and police were waiting on advice before taking over the investigation.

"Looks like he tried to put it (the plane) into a glide and lost control and spiralled and hit the ground," Sgt Taws said.

"It appears that the engine has cut out mid-flight and he has crashed into the paddock."

A police unit was sent to the man's home in Launceston to notify relatives.

The incident came 13 days after a Monarch gyroplane crashed into the Tamar River.

On April 6 pilot Allan Wardill was returning from a reconnaissance for a proposed Three Peaks Race flyover when the accident happened.

He was not injured.