Crash of a Piper PA-31-350 Navajo Chieftain in Innemincka

The pilot was conducting a scheduled passenger service flight from Port Augusta with a stop at Innamincka. A commercial pilot, travelling as a non-paying passenger, occupied the co-pilot's seat to observe the operation. Two additional passengers were on board the aircraft for the entire flight. After landing at Innamincka, the aircraft was refuelled by the pilot in command and the oil levels of both engines were checked by the observer, who experienced difficulty securing the combination oil filler cap-dipsticks. He asked the pilot for instructions and, although some advice was given, the pilot did not check the security of the dipsticks. Take-off was commenced towards the north into a 10-15 knot wind with a surface temperature of about 20 degrees C. Shortly after lift-off, at the first power reduction, the observer in the co-pilot's seat advised that there was oil seeping back along the cowl from the right side oil filler hatch. The pilot reported that he increased power to both engines but believed there was no response from the right. He began an immediate left turn to complete a circuit and attempted to secure the right engine and feather the propeller. The aircraft then began a roll to the right, the nose dropped and the aircraft impacted the ground. As the aircraft rolled right and the nose dropped, the pilot reported that he had secured the left engine and feathered the propeller. The observer in the co-pilot seat reported hearing a continuous stall warning horn as the right wing began to drop. All occupants, although injured, were able to vacate the aircraft through the main cabin door. The pilot provided assistance to the passengers and then returned to the airport to summon help.