The pilot of a Rockwell Commander 114 failed to select the fullest fuel tank on take-off, which the Australian Transport Safety Bureau (ATSB) believes led to the aircraft crashing into the water 1 km north of Redcliffe Airport in QLD.
Commander VH-WMM departed Redcliffe in December 2021 on a private flight carrying the pilot and three passengers. Shortly after take-off, the engine surged then lost power completely when the Commander was in a left turn. The pilot elected to continue the left turn to get back to Redcliffe, but the aircraft lost altitude and impacted the water before turning over to settle inverted.
Although the aircraft came to rest on a mud flat in only 2 m of water, none of the occupants were able to escape.
According to the ATSB investigation report, video taken by one of the passengers showed the pilot did not carry out trouble checks after the engine stopped. The pilot also failed to maintain best glide speed and lowered the landing gear in response to a gear warning horn. The ATSB report concludes that the landing gear caused the aircraft to become inverted after ditching.
Investigators found the fuel selector set to the left tank, which likely had been emptied by cross-feeding to the right tank when WMM was parked on the ground. Calculations showed there was 115 l in the right tank.
Also, a perceived engine issue arose during the pre-take-off checks causing the pilot to taxi back to ground help, but the pilot realised they had mixed-up the propeller pitch and mixture controls.
ATSB Director Transport Safety Dr Stuart Godley said the perceived problem was a distraction for the pilot.
“During preparation for the flight, the perceived engine problem distracted the pilot during the conduct of pre-take-off checks,” Godley said.
“After rectifying the issue, the pilot did not complete the remaining pre-take-off checks, including fuel tank selection, before departure.”
It was likely that the fuel tank selection prior to take-off was to the left fuel tank only, which led to fuel starvation and engine stoppage soon after take-off, the investigation found.
“Likely experiencing the effects of stress and time pressure following the engine power reduction and then stoppage, the pilot did not conduct initial emergency actions and attempted to return to the runway for landing,” Godley said.
The Rockwell Commander 114 has a straight-and-level flapless stall speed of 63 KIAS. The passenger video recorded stall annunciation before impact with the water, which revealed the aircraft was below the best glide speed of 82 KIAS.
“This tragic accident highlights the importance of using checklists as they provide pilots with the detailed normal and emergency checks specific to the aircraft type without having to rely on committing these to memory,” Godley said.
“This ensures that aircraft are operated in a way that meets aircraft flight manual requirements and limitations.
“When distracted, restarting an interrupted checklist from the beginning is a means of ensuring that all steps to be performed are done so in order and the checklist is complete.”
The full investigation report is on the ATSB website.