Forced/precautionary landing involving a Cessna 172E, VH-DJI, 30 km east of Broome, Western Australia, on 23 June 1994

The pilot was carrying out a fence inspection at 500 feet above ground level when the engine power reduced to idle. He changed the fuel tank selector to the fullest tank but there was no response from the engine. The pilot then closed and opened the throttle lever a number of times. This resulted in an increase to 1000 revolutions per minute, but power again returned to idle when he stopped moving the throttle. As the aircraft was losing altitude the pilot discontinued his trouble shooting activities and attempted a forced landing in heavily timbered terrain. The aircraft struck a number of trees during the landing.

The only fault found during an inspection of the wreckage was a fuel tank vent line containing a wasps nest. Testing of the line indicated that the nest could move causing either a partial or full blockage. The vent outlet was covered with a piece of gauze to prevent this type of occurrence. The fuel tanks were fitted with vented fuel caps.

The reason for the loss of power was not determined.