On 29 November 2022 at about 1630 local time, the pilot of a Rockwell International 114 was conducting a private general handling demonstration for a passenger, about 3 NM (6 km) south-west of Swan Hill Airport, Victoria.
While conducting a 20° right turn at about 1,750 ft above ground level, there was a sudden loss of engine power. The propeller continued to windmill. The pilot established a glide attitude, confirmed the power loss, and attempted to restart the engine. The pilot reported that the fuel selector was changed from the right tank to ‘BOTH’, the throttle was opened a one-quarter inch, and the fuel-air mixture set to ‘rich’, but the engine did not restart. They could not recall if the electric auxiliary fuel boost pump was applied, which was required by the aircraft manufacturer’s emergency ‘airstart’ procedure. The pilot also stated that the environmental conditions during the flight were ‘very bumpy due to thermal activity.’
At about 750 ft, the pilot abandoned attempts to start the engine and committed to executing a forced landing. The landing gear and flaps were selected down, and a large field was chosen for the landing. A MAYDAY call was made and the aircraft’s location broadcast on the common traffic advisory frequency. The aircraft landed without incident.
A visual inspection of the aircraft was completed by the pilot and no damage was found. The pilot checked the fuel tanks and measured about 100 L in the left tank, and nil indication of fuel in the right tank. The pilot had checked the right tank during the pre-flight inspection and noted 65 L at that time. It was reasoned that the nil indication of the right tank was due to the angle of the aircraft at the time of the check. The pilot concluded that the engine failure was due to ‘fuel starvation due to the prolonged turn and angle of bank/choppy winds.’
The engine was restarted with the fuel tank selector on the left tank and the auxiliary fuel boost pump on. Checks were conducted and the engine performed as expected. With the belief that the power loss was due to a low fuel level, and after an assessment of the field and a discussion with the passenger, it was decided to fly back to the Swan Hill. The pilot also noted that they were close to the airport and there were other small fields available if another power loss occurred en route.
After landing at Swan Hill, further assessment of the issue was conducted. The right fuel tank was checked with the aircraft level and 47 L of fuel was indicated. However, the engine would not start or run without the auxiliary boost pump on, regardless of the fuel tank selector position. After consulting maintenance personnel, the engine-driven mechanical fuel pump was suspected to have failed. This pump had been installed new during a recent engine rebuild.
The aircraft was fitted with an engine-driven mechanical fuel pump, which provided a continuous flow of fuel to the engine. The pump design allowed pressurised fuel from the auxiliary fuel pump to flow through it in the event of a failure. The electric auxiliary fuel pump was controlled by a 2-position switch in the cockpit and was used as a boost for starting, or in the event the engine-driven pump failed.
Emergency engine airstart procedure
The pilot’s operating handbook emergency procedures checklist specified the following conditions for a windmilling engine airstart:
- maintain a minimum airspeed of 82 kt for a windmilling propeller
- fuel selector is on the fuller tank; the procedure specifically noted not to use the BOTH position
- mixture is rich
- throttle position is at least half open
- ignition switch is selected to ‘BOTH’
- auxiliary fuel pump is on.
This incident highlights the importance of sound pilot judgement and aeronautical decision‑making. The United States Federal Aviation Administration (Pilot’s Handbook of Aeronautical Knowledge) recommends pilots use the perceive, process, and perform model to aid decision-making by utilising a number of checklists. When discussing the various steps within the checklists, it was specifically noted that:
It is important to recognize the reality of an aircraft’s mechanical condition. If you find a maintenance discrepancy and then find yourself saying that it is “probably” okay to fly with it anyway, you need to revisit the consequences…
While no further issues occurred on the subsequent flight to Swan Hill, system failures can occur in many ways, often without an obvious reason and can sometimes be transient in nature. Whenever there is any doubt as to the serviceability of an aircraft, specialist assistance should be sought, and a thorough inspection completed prior to flight resuming.
It is further emphasised that pilots should also know and understand an aircraft’s emergency procedures and be able to perform them from memory.
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.