The location of the decompression panel and absence of cabin floor sealing above the main equipment centre increased the risk of liquid ingress into the aircraft’s electrical systems.
The aircraft operator’s documented design objectives did not explicitly require the protection of non-structural systems from liquid contact or ingress.
The United States Federal Aviation Administration regulations and associated guidance material did not fully address the potential harm to flight safety posed by liquid contamination of electrical system units in transport category aircraft.
The removal of fluid quantity markings from, and unapproved modifications to the helicopter’s spray tank by the operator increased the risk of overweight operations
The floor sealing around the forward galley was not of sufficient extent to prevent liquids from passing through to the under floor area.
The operator’s flight crew quick reference handbook did not include sufficient information for flight crew to manage the emergency.
Maintenance processes did not identify or correct the deterioration of the drip shield.
The Aerial Agricultural Association of Australia suggestion that an additional hazard identification check be carried out prior to a cleanup run was not routinely practiced by the pilots, or monitored by the operator.
The recording lineworker’s shoulder restraint had been repaired using an unapproved stitch pattern and density.
The operator's joint testing procedures were not comprehensive with respect to hazard identification and the use of standard phraseology.
Neither the maintenance provider, nor the helicopter operator appreciated the potential significance of mid-span transposition information to the joint testing task.
There was no direct supervision of the joint testing operations.
On 30 November 2010 the ATSB had, in close consultation with Rolls-Royce and the UK Air Accidents Investigation Branch, established that the occurrence was directly related to the fatigue cracking of an oil feed stub pipe within the No.2 engine’s HP/IP bearing support structure. The ATSB identified the following safety issue:
Practices used within the ATS Group did not ensure that NOTAMs were effectively reviewed and communicated.
The Out of Hours telephone numbers for Proserpine Airport, listed in the Jeppesen Airways Manual, were incorrect.
There were no published communications procedures or phraseology that should before used by pilots during firebombing operations to provide separation assurance at fire locations when there was no air attack supervisor present.
The lack of guidance material for the supervision of a pilot with an Agriculture Pilot (Aeroplane) Rating Grade 2 increases the risk of inadequate supervision of such a pilot
Confusion within the aerial application industry concerning the correct authorisation for a supervisor of a pilot with an Agriculture Pilot (Aeroplane) Rating Grade 2 (Ag 2) increases the risk of an inappropriately qualified person supervising such a pilot.
The training and assessment system was ineffective, in this case, because it placed an individual with deficiencies in scanning and conflict resolution in a control position.
The operator's cabin emergency procedures did not include specific crew actions to be carried out in the event of a PATR failure.
