There has been very little research conducted into the factors influencing passengers’ use of seat belts when the seat-belt sign is not illuminated, and the effectiveness of different techniques to increase the use of seat belts.
Although passengers are routinely advised after takeoff to wear their seat belts when seated, this advice typically does not reinforce how the seat belts should be worn.
The LTN-101 air data inertial reference unit (ADIRU) model had a demonstrated susceptibility to single event effects (SEE). The consideration of SEE during the design process was consistent with industry practice at the time the unit was developed, and the overall fault rates of the ADIRU were within the relevant design objectives.
There was a limitation in the algorithm used by the A330/A340 flight control primary computers (FCPCs) for processing angle of attack (AOA) data. This limitation meant that, in a very specific situation, multiple spikes in AOA from only one of the three ADIRUs could result in a nose-down elevator command.
When developing the A330/A340 flight control primary computer software in the early 1990s, the aircraft manufacturer’s system safety assessment and other development processes did not fully consider the potential effects of frequent spikes in the data from an air data inertial reference unit.
Industry practices for tracking faults or performance problems with line-replaceable units are limited, unless the units are removed for examination. Consequently, the manufacturers of aircraft equipment have incomplete information for identifying patterns or trends that can be used to improve the safety, availability or reliability of the units.
The existing take-off certification standards, which were based on the attainment of the take-off reference speeds, and flight crew training that was based on monitoring of and responding to those speeds, did not provide crews a means to detect degraded take-off acceleration.
Operation of the M-18A in accordance with Civil Aviation Safety Authority exemptions EX56/07 and EX09/07 at weights in excess of the basic Aircraft Flight Manual maximum take-off weight (MTOW), up to the MTOW listed on the Type Certificate Data Sheet, may not provide the same level of safety intended by the manufacturer when including that weight on the Type Certificate.
The operator’s training and processes in place to enable flight crew to manage distractions during the pre-departure phase did not minimise the effect of distraction during safety critical tasks.
The failure of the digital flight data recorder (DFDR) rack during the tail strike prevented the DFDR from recording subsequent flight parameters.
The lack of a designated position in the pre-flight documentation to record the green dot speed precipitated a number of informal methods of recording that value, lessening the effectiveness of the green dot check within the loadsheet confirmation procedure.
A number of operators of the PZL M-18 Dromader aircraft had not applied the appropriate service life factors to the aircraft’s time in service for operations conducted with take-off weights greater than 4,700 kg, as required by the aircraft’s service documentation. Hence the operators could not be assured that their aircraft were within their safe service life.
The lack of a requirement for a charter-specific risk assessment in this case meant that the risks associated with the charter were not adequately addressed.
The procedural and guidance framework for commercial balloon operations generally, did not provide a high level of assurance in regard to the safe conduct of low flying.
The Society of Automotive Engineers specification AS7477 was ambiguous in relation to the requirement to cold roll the head-to-shank fillet radius of MS9490-34 bolts.
A number of non-cold rolled bolts were installed on PT6A-67 series engines during manufacture and overhaul
The scheduled maintenance requirements for ex-military UH-1 series helicopters may not adequately address the increased risk of fatigue failures associated with repetitive heavy lifting operations that were not considered in the original design fatigue calculations.
There were no soft and hard triggers in the operator’s Flight Operational Quality Assurance system to monitor the selection of the aircraft’s landing gear during an approach.
The conflicting requirements and definitions in the operator’s publications in relation to the pilot not flying role had the potential to diminish the importance of monitoring as an essential element in an aircraft’s safe operation.
There was no correlation between the results of the operator’s Flight Operational Quality Assurance and Air Safety Incident Report investigations.
