The aircraft's centre of gravity varied significantly with hopper weight and could exceed both the forward and aft limits at different times during a flight.
The ATSB is satisfied that the actions taken and proposed by CASA and owner/developer of the STC will, when complete, adequately address the safety issue.
On 6 December 2011, the Australian Transport Safety Bureau advised the Civil Aviation Safety Authority (CASA) of the potential for excessive movement of the aircraft’s centre of gravity (c.g.) as the payload in the hopper is dumped or dispensed.
The ATSB also brought the safety issue to the attention of the Aerial Agricultural Association of Australia on 16 December 2011.
The ATSB is satisfied that the actions taken and proposed by the ATSB, CASA and STC holder will adequately address the safety issue.
On 22 December 2011, CASA distributed a letter to operators of the M18, M18A, and M18B Dromader advising of the potential unusual movement of the aircraft’s c.g. as the payload in the hopper is dumped or dispensed. The letter also advised operators to assess the weight and balance of their aircraft, develop new loading systems if necessary, and ensure that all pilots are familiar with the aircraft loading systems and the potential for c.g. variation.
The ATSB is satisfied that the actions taken and proposed by the ATSB, CASA and STC holder will adequately address the safety issue.
On 12 January 2012, the holder of the Supplemental Type Certificate (STC) permitting operations up to 6,600 kg take-off weight advised the ATSB that the design would be reviewed to assess and address any excessive c.g. variation that may occur as the result of hopper payload and fuel usage during a flight.
In addition, they planned to advise all operators using the STC of the potential for excessive c.g. variation.
The ATSB is satisfied that the actions taken and proposed by the ATSB, CASA and STC holder will adequately address the safety issue.
