The Civil Aviation Safety Authority has grounded Australia’s fleet of 30 Dromader M-18A aircraft following the fatal crash of Dromader VH-TZJ during firebombing activities west of Ulladulla on the NSW South Coast last month, which the ATSB has found resulted from the aircraft’s wing separating in flight.
“The grounding is to allow work to continue on reviewing safety issues relating to maintenance inspections and the operation of the aircraft.” CASA said in a statement. “CASA is obtaining maintenance data and information from the Dromader operators. This will be carefully analysed before Dromader flights resume.”
The announcement follows the ATSB’s release of an initial report on the accident, in which well regarded pilot David Black was killed, found that the aircraft’s wing separated inflight as a result of fatigue cracking.
Said the ATSB: “The on-site examination found that the left wing had separated at the joint between the outer wing and the centre wing sections. The ATSB team examined the joints closely to determine the failure mode that resulted in the in-flight separation of the wing. Preliminary examination indicated that the left outer wing lower attachment lug had fractured through an area of pre-existing fatigue cracking in the lug lower ligament. The fatigue cracking reduced the structural integrity of the fitting to the point where operational loads produced an overstress fracture of the remaining lug material.”