The aircraft took off from Coonagh Airfield at 13.30 hours. The pilot had his father and young son on board as passengers and this was planned to be a sightseeing flight. The intended flight was outside controlled airspace and no flight plan had been filed with Shannon ATC. The pilot intended to fly NE across country along the east side of Lough Derg on the river Shannon as far as Garrykennedy and to return to Coonagh. Whilst over Killaloe in a descent inbound for Coonagh, the engine spluttered, the RPM decayed and after the propeller wind-milling for some time, it stopped rotating. The pilot then picked out a landing field, turned through 270º and commenced his forced landing. As the aircraft flared the belly of the fuselage caught a boulder in the field’s perimeter hedge and the aircraft came to rest close to the hedge. All the occupants exited the aircraft unaided. There was no fire.