The pilot had failed to return from a flight in the local area. A search was organised, and the wreckage of the aircraft was located the following morning. It had crashed into a swampy area and the pilot, although still alive, was seriously injured and unconscious. Although he subsequently survived his injuries he has no recall whatever of the accident sequence. Inspection of the wreckage indicated that the aircraft had hit the swamp in a flat attitude at a high vertical velocity but with little forward speed. The propeller was undamaged and appeared to have been stopped at the time of impact. A subsequent check of the engine revealed a faulty magneto. The precise nature of the fault was not determined but the engine would not start or run until an alternative ignition system was fitted. The engine then ran perfectly and no other faults were found with it. This particular engine was fitted with a single ignition system, as permitted by existing regulations.