During a visual approach to Runway 32 the engine began to run roughly, to the extent that no useful power was available. The pilot made a "Mayday" call and elected to attempt a forced landing on Runway 05. In the latter stages of the approach it became obvious to the pilot that the aircraft would not reach the runway. It flew into a tall sugar cane crop and overturned at low speed. The cane cushioned the final impact. Investigation revealed that both magnetos contained leaking, obsolete coils. They had overheated, causing the ignition to fail. The coils were clear case coils which should have been withdrawn from service in the early 1970's in accordance with a specific Airworthiness Directive (AD). The AD had been withdrawn when it was considered that Licenced Aircraft Maintenance Engineers (LAMEs) in the aviation industry were sufficiently aware of the hazards posed by these coils and that all in-service clear case coils had been replaced. At engine runup, both magnetos had checked serviceable because the coils were cold. During the flight, they had heated sufficiently to cause an internal breakdown of their function, resulting in a significant power loss. The pilot misjudged the subsequent forced landing and the aircraft undershot the runway threshold.
