Occurrence Briefs are concise reports that detail the facts surrounding a transport safety occurrence, as received in the initial notification and any follow-up enquiries. They provide an opportunity to share safety messages in the absence of an investigation.
On 4 September 2020 at 1300 Eastern Standard Time, a pilot and instructor were conducting training in a Piper PA-31-325, 9 NM south of Cambridge, Tasmania. The instructor was training the pilot with a simulated engine fire, including engine shutdown, feathering of the propeller and cross feeding of fuel.
Once the simulated exercise began, the pilot worked through the checklist for securing an inoperative engine. The pilot completed the checklist, which included closing the firewall shut-off lever, closing the throttle and feathering the propeller. The pilot then began going through the stages of returning the aircraft to normal flight operations. While they were unfeathering the propeller, the revolutions per minute of the propeller unexpectedly accelerated and the pilot returned it back to the feathered stage. Engine power could not be restored, and the instructor made the decision to shut down the no.1 engine. The pilot suggested diverting the aircraft to Hobart. The instructor agreed and contacted air traffic control, declaring a PAN PAN before diverting the aircraft to Hobart. The aircraft landed safely and was met by engineers from the instructor’s company.
During the post-flight inspection, engineers discovered that the no.1 engine firewall shut-off lever was still in the closed position. When the training exercise was over, the firewall shut-off lever should have been in the open position. Because of this, the no.1 engine was unable to return to full power during the unfeathering procedure, which subsequently led to the in-flight engine shutdown.
This incident highlights the importance of pilots having a good working knowledge of aircraft systems and checklists prior to practicing emergency procedures. In this instance, the checklist for unfeathering the engine did not include a check of the firewall shut-off lever. As a result, the firewall shut-off lever was left in the closed position, resulting in the loss of engine power.
About this report
Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.