The Coulson Aviation crew resource management practice of limiting the pilot monitoring (PM) announcements to deviations outside the target retardant drop parameter tolerances increased the risk of the aircraft entering an unrecoverable state before the PM would alert the pilot flying.
Coulson Aviation have not advised the ATSB of any safety action taken to address this safety issue and therefore the ATSB issues the following safety recommendation.
The Australian Transport Safety Bureau recommends that Coulson Aviation takes safety action to address their crew resource management procedures for retardant drops to reduce the risk of the aircraft entering an unrecoverable state before the pilot monitoring alerts the pilot flying.